appypod-rattail/gen/mixins/__init__.py

'''This package contains mixin classes that are mixed in with generated classes:
   - mixins/BaseMixin is mixed in with standard Zope classes;
   - mixins/ToolMixin is mixed in with the generated application Tool class.'''

# ------------------------------------------------------------------------------
import os, os.path, re, sys, types, urllib, cgi
from appy import Object
from appy.px import Px
from appy.fields.workflow import UiTransition
import appy.gen as gen
from appy.gen.utils import *
from appy.gen.layout import Table
from appy.gen.descriptors import WorkflowDescriptor, ClassDescriptor
from appy.shared import utils as sutils
from appy.shared.data import rtlLanguages
from appy.shared.xml_parser import XmlMarshaller, XmlUnmarshaller
from appy.shared.diff import HtmlDiff

# ------------------------------------------------------------------------------
NUMBERED_ID = re.compile('.+\d{4}$')

# ------------------------------------------------------------------------------
class BaseMixin:
    '''Every Zope class generated by appy.gen inherits from this class or a
       subclass of it.'''
    _appy_meta_type = 'Class'

    def get_o(self):
        '''In some cases, we want the Zope object, we don't know if the current
           object is a Zope or Appy object. By defining this property,
           "someObject.o" produces always the Zope object, be someObject an Appy
           or Zope object.'''
        return self
    o = property(get_o)

    def getInitiatorInfo(self, appy=False):
        '''Gets information about a potential initiator object from the request.
           Returns a 2-tuple (initiator, field):
           * initiator is the initiator (Zope or Appy) object;
           * field is the Ref instance.
        '''
        rq = self.REQUEST
        if not rq.get('nav', '').startswith('ref.'): return None, None
        splitted = rq['nav'].split('.')
        initiator = self.getTool().getObject(splitted[1])
        field = initiator.getAppyType(splitted[2])
        if appy: initiator = initiator.appy()
        return initiator, field

    def createOrUpdate(self, created, values,
                       initiator=None, initiatorField=None):
        '''This method creates (if p_created is True) or updates an object.
           p_values are manipulated versions of those from the HTTP request.
           In the case of an object creation from the web (p_created is True
           and a REQUEST object is present), p_self is a temporary object
           created in /temp_folder, and this method moves it at its "final"
           place. In the case of an update, this method simply updates fields
           of p_self.'''
        rq = getattr(self, 'REQUEST', None)
        obj = self
        if created and rq:
            # Create the final object and put it at the right place.
            tool = self.getTool()
            # The app may define a method klass.generateUid for producing an UID
            # for instance of this class. If no such method is found, we use the
            # standard Appy method to produce an UID.
            id = None
            klass = tool.getAppyClass(obj.portal_type)
            if hasattr(klass, 'generateUid'):
                id = klass.generateUid(obj.REQUEST)
            if not id:
                id = tool.generateUid(obj.portal_type)
            if not initiator:
                folder = tool.getPath('/data')
            else:
                folder = initiator.getCreateFolder()
                # Check that the user can add objects through this Ref.
                initiatorField.checkAdd(initiator)
            obj = createObject(folder, id, obj.portal_type, tool.getAppName())
        # Get the fields on the current page
        fields = None
        if rq: fields = self.getAppyTypes('edit', rq.get('page'))
        # Remember the previous values of fields, for potential historization
        previousData = None
        if not created and fields:
            previousData = obj.rememberPreviousData(fields)
        # Perform the change on the object
        if fields:
            # Store in the database the new value coming from the form
            for field in fields:
                value = getattr(values, field.name, None)
                field.store(obj, value)
        if previousData:
            # Keep in history potential changes on historized fields
            obj.historizeData(previousData)

        # Call the custom "onEditEarly" if available. This method is called
        # *before* potentially linking the object to its initiator.
        appyObject = obj.appy()
        if created and hasattr(appyObject, 'onEditEarly'):
            appyObject.onEditEarly()

        # Manage potential link with an initiator object
        if created and initiator:
            initiator.appy().link(initiatorField.name, appyObject)

        # Call the custom "onEdit" if available
        msg = None # The message to display to the user. It can be set by onEdit
        if hasattr(appyObject, 'onEdit'): msg = appyObject.onEdit(created)

        # Update last modification date
        if not created:
            from DateTime import DateTime
            obj.modified = DateTime()
        # Unlock the currently saved page on the object
        if rq: self.removeLock(rq['page'])
        obj.reindex()
        return obj, msg

    def updateField(self, name, value):
        '''Updates a single field p_name with new p_value.'''
        field = self.getAppyType(name)
        # Remember previous value if the field is historized.
        previousData = self.rememberPreviousData([field])
        # Store the new value into the database
        field.store(self, value)
        # Update the object history when relevant
        if previousData: self.historizeData(previousData)
        # Update last modification date
        from DateTime import DateTime
        self.modified = DateTime()

    def delete(self):
        '''This method is self's suicide.'''
        # Call a custom "onDelete" if it exists
        appyObj = self.appy()
        if hasattr(appyObj, 'onDelete'): appyObj.onDelete()
        # Any people referencing me must forget me now
        for field in self.getAllAppyTypes():
            if field.type != 'Ref': continue
            for obj in field.getValue(self):
                field.back.unlinkObject(obj, appyObj, back=True)
        # Uncatalog the object
        self.reindex(unindex=True)
        # Delete the filesystem folder corresponding to this object
        folder = os.path.join(*self.getFsFolder())
        if os.path.exists(folder):
            sutils.FolderDeleter.delete(folder)
            sutils.FolderDeleter.deleteEmpty(os.path.dirname(folder))
        # Delete the object
        self.getParentNode().manage_delObjects([self.id])

    def onDelete(self):
        '''Called when an object deletion is triggered from the ui'''
        rq = self.REQUEST
        tool = self.getTool()
        obj = tool.getObject(rq['uid'])
        obj.delete()
        msg = obj.translate('action_done')
        # If we are called from an Ajax request, simply return msg
        if hasattr(rq, 'pxContext') and rq.pxContext['ajax']: return msg
        if obj.getUrl(rq['HTTP_REFERER'], mode='raw') == obj.getUrl(mode='raw'):
            # We were consulting the object that has been deleted. Go back to
            # the main page.
            urlBack = tool.getSiteUrl()
        else:
            urlBack = obj.getUrl(rq['HTTP_REFERER'])
        obj.say(msg)
        obj.goto(urlBack)

    def onDeleteEvent(self):
        '''Called when an event (from object history) deletion is triggered
           from the ui.'''
        rq = self.REQUEST
        # Re-create object history, but without the event corresponding to
        # rq['eventTime']
        history = []
        from DateTime import DateTime
        eventToDelete = DateTime(rq['eventTime'])
        for event in self.workflow_history['appy']:
            if (event['action'] != '_datachange_') or \
               (event['time'] != eventToDelete):
                history.append(event)
        self.workflow_history['appy'] = tuple(history)
        appy = self.appy()
        self.log('data change event deleted for %s.' % appy.uid)
        self.goto(self.getUrl(rq['HTTP_REFERER']))

    def onLink(self):
        '''Called when object (un)linking is triggered from the ui.'''
        rq = self.REQUEST
        tool = self.getTool()
        sourceObject = tool.getObject(rq['sourceUid'])
        field = sourceObject.getAppyType(rq['fieldName'])
        return field.onUiRequest(sourceObject, rq)

    def onCreate(self):
        '''This method is called when a user wants to create a root object in
           the "data" folder or an object through a reference field. A temporary
           object is created in /temp_folder and the edit page to it is
           returned.'''
        rq = self.REQUEST
        className = rq.get('className')
        # Create the params to add to the URL we will redirect the user to
        # create the object.
        urlParams = {'mode':'edit', 'page':'main', 'nav':'',
                     'inPopup':rq.get('popup') == '1'}
        initiator, initiatorField = self.getInitiatorInfo()
        if initiator:
            # The object to create will be linked to an initiator object through
            # a Ref field. We create here a new navigation string with one more
            # item, that will be the currently created item.
            splitted = rq.get('nav').split('.')
            splitted[-1] = splitted[-2] = str(int(splitted[-1])+1)
            urlParams['nav'] = '.'.join(splitted)
            # Check that the user can add objects through this Ref field
            initiatorField.checkAdd(initiator)
        # Create a temp object in /temp_folder
        tool = self.getTool()
        id = tool.generateUid(className)
        appName = tool.getAppName()
        obj = createObject(tool.getPath('/temp_folder'), id, className, appName)
        return self.goto(obj.getUrl(**urlParams))

    def getDbFolder(self):
        '''Gets the folder, on the filesystem, where the database (Data.fs and
           sub-folders) lies.'''
        return os.path.dirname(self.getTool().getApp()._p_jar.db().getName())
        
    def getFsFolder(self, create=False):
        '''Gets the folder where binary files tied to this object will be stored
           on the filesystem. If p_create is True and the folder does not exist,
           it is created (together with potentially missing parent folders).
           This folder is returned as a tuple (s_baseDbFolder, s_subPath).'''
        objId = self.id
        # Get the root folder where Data.fs lies.
        dbFolder = self.getDbFolder()
        # Build the list of path elements within this db folder.
        path = []
        inConfig = False
        for elem in self.getPhysicalPath():
            if not elem: continue
            if elem == 'data': continue
            if elem == 'config': inConfig = True
            if not path or ((len(path) == 1) and inConfig):
                # This object is at the root of the filesystem.
                if NUMBERED_ID.match(elem):
                    path.append(elem[-4:])
            path.append(elem)
            # We are done if elem corresponds to the object id.
            if elem == objId: break
        path = os.sep.join(path)
        if create:
            fullPath = os.path.join(dbFolder, path)
            if not os.path.exists(fullPath): os.makedirs(fullPath)
        return dbFolder, path

    def view(self):
        '''Returns the view PX.'''
        obj = self.appy()
        return obj.pxView({'obj': obj, 'tool': obj.tool})

    def edit(self):
        '''Returns the edit PX.'''
        obj = self.appy()
        return obj.pxEdit({'obj': obj, 'tool': obj.tool})

    def ajax(self):
        '''Called via an Ajax request to render some PX whose name is in the
           request.'''
        obj = self.appy()
        return obj.pxAjax({'obj': obj, 'tool': obj.tool})

    def setLock(self, user, page):
        '''A p_user edits a given p_page on this object: we will set a lock, to
           prevent other users to edit this page at the same time.'''
        if not hasattr(self.aq_base, 'locks'):
            # Create the persistent mapping that will store the lock
            # ~{s_page: (s_userId, DateTime_lockDate)}~
            from persistent.mapping import PersistentMapping
            self.locks = PersistentMapping()
        # Raise an error is the page is already locked by someone else. If the
        # page is already locked by the same user, we don't mind: he could have
        # used back/forward buttons of its browser...
        userId = user.login
        if (page in self.locks) and (userId != self.locks[page][0]):
            self.raiseUnauthorized('This page is locked.')
        # Set the lock
        from DateTime import DateTime
        self.locks[page] = (userId, DateTime())

    def isLocked(self, user, page):
        '''Is this page locked? If the page is locked by the same user, we don't
           mind and consider the page as unlocked. If the page is locked, this
           method returns the tuple (userId, lockDate).'''
        if hasattr(self.aq_base, 'locks') and (page in self.locks):
            if (user.login != self.locks[page][0]): return self.locks[page]

    def removeLock(self, page, force=False):
        '''Removes the lock on the current page. This happens:
           - after the page has been saved: the lock must be released;
           - or when an admin wants to force the deletion of a lock that was
             left on p_page for too long (p_force=True).
        '''
        if page not in self.locks: return
        # Raise an error if the user that saves changes is not the one that
        # has locked the page (excepted if p_force is True)
        if not force:
            userId = self.getTool().getUser().login
            if self.locks[page][0] != userId:
                self.raiseUnauthorized('This page was locked by someone else.')
        # Remove the lock
        del self.locks[page]

    def removeMyLock(self, user, page):
        '''If p_user has set a lock on p_page, this method removes it. This
           method is called when the user that locked a page consults
           pxView for this page. In this case, we consider that the user has
           left the edit page in an unexpected way and we remove the lock.'''
        if hasattr(self.aq_base, 'locks') and (page in self.locks) and \
           (user.login == self.locks[page][0]):
            del self.locks[page]

    def onUnlock(self):
        '''Called when an admin wants to remove a lock that was left for too
           long by some user.'''
        rq = self.REQUEST
        tool = self.getTool()
        obj = tool.getObject(rq['objectUid'])
        obj.removeLock(rq['pageName'], force=True)
        urlBack = self.getUrl(rq['HTTP_REFERER'])
        self.say(self.translate('action_done'))
        self.goto(urlBack)

    def intraFieldValidation(self, errors, values):
        '''This method performs field-specific validation for every field from
           the page that is being created or edited. For every field whose
           validation generates an error, we add an entry in p_errors. For every
           field, we add in p_values an entry with the "ready-to-store" field
           value.'''
        rq = self.REQUEST
        for field in self.getAppyTypes('edit', rq.form.get('page')):
            if not field.validable or not field.isClientVisible(self): continue
            value = field.getRequestValue(self)
            message = field.validate(self, value)
            if message:
                setattr(errors, field.name, message)
            else:
                setattr(values, field.name, field.getStorableValue(self, value))
            # Validate sub-fields within Lists
            if field.type != 'List': continue
            i = -1
            for row in value:
                i += 1
                for name, subField in field.fields:
                    message = subField.validate(self, getattr(row,name,None))
                    if message:
                        setattr(errors, '%s*%d' % (subField.name, i), message)

    def interFieldValidation(self, errors, values):
        '''This method is called when individual validation of all fields
           succeed (when editing or creating an object). Then, this method
           performs inter-field validation. This way, the user must first
           correct individual fields before being confronted to potential
           inter-field validation errors.'''
        obj = self.appy()
        if not hasattr(obj, 'validate'): return
        msg = obj.validate(values, errors)
        # Those custom validation methods may have added fields in the given
        # p_errors object. Within this object, for every error message that is
        # not a string, we replace it with the standard validation error for the
        # corresponding field.
        for key, value in errors.__dict__.iteritems():
            resValue = value
            if not isinstance(resValue, basestring):
                resValue = self.translate('field_invalid')
            setattr(errors, key, resValue)
        return msg

    def onUpdate(self):
        '''This method is executed when a user wants to update an object.
           The object may be a temporary object created in /temp_folder.
           In this case, the update consists in moving it to its "final" place.
           If the object is not a temporary one, this method updates its
           fields in the database.'''
        rq = self.REQUEST
        tool = self.getTool()
        errorMessage = self.translate('validation_error')
        isNew = self.isTemporary()
        inPopup = rq.get('popup') == '1'
        # If this object is created from an initiator, get info about him
        initiator, initiatorField = self.getInitiatorInfo()
        initiatorPage = initiatorField and initiatorField.pageName or None
        # If the user clicked on 'Cancel', go back to the previous page
        buttonClicked = rq.get('button')
        if buttonClicked == 'cancel':
            if inPopup: back = tool.backFromPopup()
            elif initiator: # Go back to the initiator page
                urlBack = initiator.getUrl(page=initiatorPage, nav='')
            else:
                if isNew: urlBack = tool.getHomePage() # Go back to home page
                else:
                    # Return to the same page, excepted if unshowable on view
                    phaseObj = self.getAppyPhases(True, 'view')
                    pageInfo = phaseObj.getPageInfo(rq['page'], 'view')
                    if not pageInfo: urlBack = tool.getHomePage()
                    else: urlBack = self.getUrl(page=pageInfo.page.name)
            self.removeLock(rq['page'])
            self.say(self.translate('object_canceled'))
            if inPopup: return back
            return self.goto(urlBack)

        # Object for storing validation errors
        errors = Object()
        # Object for storing the (converted) values from the request
        values = Object()

        # Trigger field-specific validation
        self.intraFieldValidation(errors, values)
        if errors.__dict__:
            for k,v in errors.__dict__.iteritems(): rq.set('%s_error' % k, v)
            self.say(errorMessage)
            return self.gotoEdit()

        # Trigger inter-field validation
        msg = self.interFieldValidation(errors, values)
        if not msg: msg = errorMessage
        if errors.__dict__:
            for k,v in errors.__dict__.iteritems(): rq.set('%s_error' % k, v)
            self.say(msg)
            return self.gotoEdit()

        # Before saving data, must we ask a confirmation by the user ?
        appyObj = self.appy()
        saveConfirmed = rq.get('confirmed') == 'True'
        if hasattr(appyObj, 'confirm') and not saveConfirmed:
            msg = appyObj.confirm(values)
            if msg:
                rq.set('confirmMsg', msg.replace("'", "\\'"))
                return self.gotoEdit()

        # Create or update the object in the database
        obj, msg = self.createOrUpdate(isNew, values, initiator, initiatorField)

        # Redirect the user to the appropriate page
        if not msg: msg = self.translate('object_saved')
        # If the object has already been deleted (ie, it is a kind of transient
        # object like a one-shot form and has already been deleted in method
        # onEdit) or if the user can't access the object anymore, redirect him
        # to the user's home page.
        if not getattr(obj.getParentNode().aq_base, obj.id, None) or \
           not obj.mayView():
            if inPopup: return tool.backFromPopup()
            return self.goto(tool.getHomePage(), msg)
        if (buttonClicked == 'save') or saveConfirmed:
            obj.say(msg)
            if inPopup: return tool.backFromPopup()
            if isNew and initiator:
                return self.goto(initiator.getUrl(page=initiatorPage, nav=''))
            # Return to the same page, if showable on view
            phaseObj = self.getAppyPhases(True, 'view')
            pageInfo = phaseObj.getPageInfo(rq['page'], 'view')
            if not pageInfo: return self.goto(tool.getHomePage(), msg)
            return self.goto(obj.getUrl(page=pageInfo.page.name))
        # Get the current page name. We keep it in "pageName" because rq['page']
        # can be changed by m_getAppyPhases called below.
        pageName = rq['page']
        if buttonClicked in ('previous', 'next'):
            # Go to the previous or next page for this object. We recompute the
            # list of phases and pages because things may have changed since the
            # object has been updated (ie, additional pages may be shown or
            # hidden now, so the next and previous pages may have changed).
            # Moreover, previous and next pages may not be available in "edit"
            # mode, so we return the edit or view pages depending on page.show.
            phaseObj = self.getAppyPhases(True, 'edit')
            methodName = 'get%sPage' % buttonClicked.capitalize()
            pageName, pageInfo = getattr(phaseObj, methodName)(pageName)
            if pageName:
                # Return to the edit or view page?
                if pageInfo.showOnEdit:
                    # I do not use gotoEdit here because I really need to
                    # redirect the user to the edit page. Indeed, the object
                    # edit URL may have moved from temp_folder to another place.
                    return self.goto(obj.getUrl(mode='edit', page=pageName,
                                                inPopup=inPopup))
                else:
                    return self.goto(obj.getUrl(page=pageName, inPopup=inPopup))
            else:
                obj.say(msg)
                return self.goto(obj.getUrl(inPopup=inPopup))
        return obj.gotoEdit()

    def reindex(self, indexes=None, unindex=False):
        '''Reindexes this object the catalog. If names of indexes are specified
           in p_indexes, recataloging is limited to those indexes. If p_unindex
           is True, instead of cataloguing the object, it uncatalogs it.'''
        path = '/'.join(self.getPhysicalPath())
        catalog = self.getPhysicalRoot().catalog
        if unindex:
            catalog.uncatalog_object(path)
        else:
            if indexes:
                catalog.catalog_object(self, path, idxs=indexes)
            else:
                # Get the list of indexes that apply on this object. Else, Zope
                # will reindex all indexes defined in the catalog, and through
                # acquisition, wrong methods can be called on wrong objects.
                iNames = self.wrapperClass.getIndexes().keys()
                catalog.catalog_object(self, path, idxs=iNames)

    def xml(self, action=None):
        '''If no p_action is defined, this method returns the XML version of
           this object. Else, it calls method named p_action on the
           corresponding Appy wrapper and returns, as XML, its result.'''
        self.REQUEST.RESPONSE.setHeader('Content-Type','text/xml;charset=utf-8')
        # Check if the user is allowed to consult this object
        if not self.mayView(): return XmlMarshaller().marshall('Unauthorized')
        if not action:
            marshaller = XmlMarshaller(rootTag=self.getClass().__name__,
                                       dumpUnicode=True)
            res = marshaller.marshall(self, objectType='appy')
        else:
            appyObj = self.appy()
            try:
                methodRes = getattr(appyObj, action)()
                if isinstance(methodRes, Px):
                    res = methodRes({'self': self.appy()})
                elif isinstance(methodRes, file):
                    res = methodRes.read()
                    methodRes.close()
                elif isinstance(methodRes, basestring) and \
                     methodRes.startswith('<?xml'): # Already XML
                    return methodRes
                else:
                    marshaller = XmlMarshaller()
                    oType = isinstance(methodRes, Object) and 'popo' or 'appy'
                    res = marshaller.marshall(methodRes, objectType=oType)
            except Exception, e:
                tb = sutils.Traceback.get()
                res = XmlMarshaller(rootTag='exception').marshall(tb)
                self.log(tb, type='error')
                import transaction
                transaction.abort()
        return res

    def say(self, msg, type='info'):
        '''Prints a p_msg in the user interface. p_logLevel may be "info",
           "warning" or "error".'''
        rq = self.REQUEST
        if 'messages' not in rq.SESSION.keys():
            plist = self.getProductConfig().PersistentList
            messages = rq.SESSION['messages'] = plist()
        else:
            messages = rq.SESSION['messages']
        messages.append( (type, msg) )

    def log(self, msg, type='info'):
        '''Logs a p_msg in the log file. p_logLevel may be "info", "warning"
           or "error".'''
        logger = self.getProductConfig().logger
        if type == 'warning': logMethod = logger.warn
        elif type == 'error': logMethod = logger.error
        else: logMethod = logger.info
        user = self.getTool().getUser()
        # There could be not user at all (even not "anon") if we are trying to
        # authenticate an inexistent user for example.
        login = user and user.login or 'anon'
        logMethod('%s: %s' % (login, msg))

    def do(self):
        '''Performs some action from the user interface.'''
        rq = self.REQUEST
        action = rq['action']
        if rq.get('objectUid', None):
            obj = self.getTool().getObject(rq['objectUid'])
        else:
            obj = self
        if rq.get('appy', None) == '1': obj = obj.appy()
        return getattr(obj, 'on'+action)()

    def raiseUnauthorized(self, msg=None):
        '''Raise an error "Unauthorized access".'''
        from AccessControl import Unauthorized
        if msg: raise Unauthorized(msg)
        raise Unauthorized()

    def rememberPreviousData(self, fields):
        '''This method is called before updating an object and remembers, for
           every historized field, the previous value. Result is a dict
           ~{s_fieldName: previousFieldValue}~'''
        res = {}
        for field in fields:
            if not field.getAttribute(self, 'historized'): continue
            res[field.name] = field.getValue(self)
        return res

    def addHistoryEvent(self, action, **kw):
        '''Adds an event in the object history.'''
        user = self.getTool().getUser()
        userId = user and user.login or 'system'
        from DateTime import DateTime
        event = {'action': action, 'actor': userId, 'time': DateTime(),
                 'comments': ''}
        event.update(kw)
        if 'review_state' not in event: event['review_state'] = self.State()
        # Add the event to the history
        self.workflow_history['appy'] += (event,)

    def addDataChange(self, changes, notForPreviouslyEmptyValues=False):
        '''This method allows to add "manually" a data change into the objet's
           history. Indeed, data changes are "automatically" recorded only when
           a HTTP form is uploaded, not if, in the code, a setter is called on
           a field. The method is also called by m_historizeData below, that
           performs "automatic" recording when a HTTP form is uploaded. Field
           changes for which the previous value was empty are not recorded into
           the history if p_notForPreviouslyEmptyValues is True.

           For a multilingual string field, p_changes can contain a key for
           every language, of the form <field name>-<language>.'''
        # Add to the p_changes dict the field labels
        for name in changes.keys():
            # "name" can contain the language for multilingual fields.
            if '-' in name:
                fieldName, lg = name.split('-')
            else:
                fieldName = name
                lg = None
            field = self.getAppyType(fieldName)
            if notForPreviouslyEmptyValues:
                # Check if the previous field value was empty
                if lg:
                    isEmpty = not changes[name] or not changes[name].get(lg)
                else:
                    isEmpty = field.isEmptyValue(self, changes[name])
                if isEmpty:
                    del changes[name]
            else:
                changes[name] = (changes[name], field.labelId)
        # Add an event in the history
        self.addHistoryEvent('_datachange_', changes=changes)

    def historizeData(self, previousData):
        '''Records in the object history potential changes on historized fields.
           p_previousData contains the values, before an update, of the
           historized fields, while p_self already contains the (potentially)
           modified values.'''
        # Remove from previousData all values that were not changed
        for name in previousData.keys():
            field = self.getAppyType(name)
            prev = previousData[name]
            curr = field.getValue(self)
            try:
                if (prev == curr) or ((prev == None) and (curr == '')) or \
                   ((prev == '') and (curr == None)):
                    del previousData[name]
                    continue
            except UnicodeDecodeError, ude:
                # The string comparisons above may imply silent encoding-related
                # conversions that may produce this exception.
                continue
            # In some cases the old value must be formatted.
            if field.type == 'Ref':
                previousData[name] = [r.o.getShownValue('title') \
                                      for r in previousData[name]]
            elif field.type == 'String':
                languages = field.getAttribute(self, 'languages')
                if len(languages) > 1:
                    # Consider every language-specific value as a first-class
                    # value.
                    del previousData[name]
                    for lg in languages:
                        lgPrev = prev and prev.get(lg) or None
                        lgCurr = curr and curr.get(lg) or None
                        if lgPrev == lgCurr: continue
                        previousData['%s-%s' % (name, lg)] = lgPrev
        if previousData:
            self.addDataChange(previousData)

    def goto(self, url, msg=None):
        '''Brings the user to some p_url after an action has been executed.'''
        if msg: self.say(msg)
        return self.REQUEST.RESPONSE.redirect(url)

    def gotoEdit(self):
        '''Brings the user to the edit page for this object. This method takes
           care of not carrying any password value. Unlike m_goto above, there
           is no HTTP redirect here: we execute directly PX "edit" and we
           return the result.'''
        page = self.REQUEST.get('page', 'main')
        for field in self.getAppyTypes('edit', page):
            if (field.type == 'String') and (field.format in (3,4)):
                self.REQUEST.set(field.name, '')
        return self.edit()

    def gotoTied(self):
        '''Redirects the user to an object tied to this one.'''
        return self.getAppyType(self.REQUEST['field']).onGotoTied(self)

    def getCreateFolder(self):
        '''When an object must be created from this one through a Ref field, we
           must know where to put the newly create object: within this one if it
           is folderish, besides this one in its parent else.
        '''
        if self.isPrincipiaFolderish: return self
        return self.getParentNode()

    def getFieldValue(self, name, layoutType=None, outerValue=None):
        '''Returns the database value of field named p_name for p_self.'''
        if layoutType == 'search': return # No object in search screens
        field = self.getAppyType(name)
        if field.type == 'Pod': return
        if '*' not in name: return field.getValue(self)
        # The field is an inner field from a List.
        listName, name, i = name.split('*')
        listType = self.getAppyType(listName)
        return listType.getInnerValue(self, outerValue, name, int(i))

    def getRequestFieldValue(self, name):
        '''Gets the value of field p_name as may be present in the request.'''
        # Return the request value for standard fields.
        if '*' not in name:
            return self.getAppyType(name).getRequestValue(self)
        # For sub-fields within Lists, the corresponding request values have
        # already been computed in the request key corresponding to the whole
        # List.
        listName, name, rowIndex = name.split('*')
        rowIndex = int(rowIndex)
        if rowIndex == -1: return ''
        allValues = self.REQUEST.get(listName)
        if not allValues: return ''
        return getattr(allValues[rowIndex], name, '')

    def isDebug(self):
        '''Are we in debug mode ?'''
        for arg in sys.argv:
            if arg == 'debug-mode=on': return True

    def getClass(self, reloaded=False):
        '''Returns the Appy class that dictates self's behaviour.'''
        if not reloaded:
            return self.getTool().getAppyClass(self.__class__.__name__)
        else:
            klass = self.appy().klass
            moduleName = klass.__module__
            exec 'import %s' % moduleName
            exec 'reload(%s)' % moduleName
            exec 'res = %s.%s' % (moduleName, klass.__name__)
            # More manipulations may have occurred in m_update
            if hasattr(res, 'update'):
                parentName= res.__bases__[-1].__name__
                moduleName= 'Products.%s.wrappers' % self.getTool().getAppName()
                exec 'import %s' % moduleName
                exec 'parent = %s.%s' % (moduleName, parentName)
                res.update(parent)
            return res

    def getAppyType(self, name, className=None):
        '''Returns the Appy type named p_name. If no p_className is defined, the
           field is supposed to belong to self's class.'''
        isInnerType = '*' in name # An inner type lies within a List type.
        subName = None
        if isInnerType:
            elems = name.split('*')
            if len(elems) == 2: name, subName = elems
            else:               name, subName, i = elems
        if not className:
            klass = self.__class__.wrapperClass
        else:
            klass = self.getTool().getAppyClass(className, wrapper=True)
        res = getattr(klass, name, None)
        if res and isInnerType: res = res.getField(subName)
        return res

    def getAllAppyTypes(self, className=None):
        '''Returns the ordered list of all Appy types for self's class if
           p_className is not specified, or for p_className else.'''
        if not className:
            klass = self.__class__.wrapperClass
        else:
            klass = self.getTool().getAppyClass(className, wrapper=True)
        return klass.__fields__

    def getGroupedFields(self, layoutType, pageName, cssJs=None):
        '''Returns the fields sorted by group. If a dict is given in p_cssJs,
           we will add it in the css and js files required by the fields.'''
        res = []
        groups = {} # The already encountered groups
        # If a dict is given in p_cssJs, we must fill it with the CSS and JS
        # files required for every returned field.
        collectCssJs = isinstance(cssJs, dict)
        css = js = None
        config = self.getProductConfig(True)
        # If param "refresh" is there, we must reload the Python class
        refresh = ('refresh' in self.REQUEST)
        if refresh: klass = self.getClass(reloaded=True)
        for field in self.getAllAppyTypes():
            if refresh: field = field.reload(klass, self)
            if field.page.name != pageName: continue
            if not field.isShowable(self, layoutType): continue
            if collectCssJs:
                if css == None: css = []
                field.getCss(layoutType, css, config)
                if js == None: js = []
                field.getJs(layoutType, js, config)
            if not field.group:
                res.append(field)
            else:
                # Insert the UiGroup instance corresponding to field.group
                uiGroup = field.group.insertInto(res, groups, field.page,
                                                 self.meta_type)
                uiGroup.addElement(field)
        if collectCssJs:
            cssJs['css'] = css or ()
            cssJs['js'] = js or ()
        return res

    def getAppyTypes(self, layoutType, pageName, type=None):
        '''Returns the list of fields that belong to a given page (p_pageName)
           for a given p_layoutType. If p_pageName is None, fields of all pages
           are returned. If p_type is defined, only fields of this p_type are
           returned. '''
        res = []
        for field in self.getAllAppyTypes():
            if pageName and (field.page.name != pageName): continue
            if type and (field.type != type): continue
            if not field.isRenderable(layoutType): continue
            if not field.isShowable(self, layoutType): continue
            res.append(field)
        return res

    def getSlavesRequestInfo(self, pageName):
        '''When slave fields must be updated via Ajax requests, we must carry
           some information from the global request object to the ajax requests:
           - the selected values in slave fields;
           - validation errors.'''
        requestValues = {}
        errors = {}
        req = self.REQUEST
        for field in self.getAllAppyTypes():
            if field.page.name != pageName: continue
            if field.masterValue and callable(field.masterValue):
                # We have a slave field that is updated via ajax requests.
                name = field.name
                # Remember the request value for this field if present.
                if req.has_key(name) and req[name]:
                    requestValues[name] = req[name]
                # Remember the validation error for this field if present.
                errorKey = '%s_error' % name
                if req.has_key(errorKey):
                    errors[name] = req[errorKey]
        return sutils.getStringDict(requestValues), sutils.getStringDict(errors)

    def getCssJs(self, fields, layoutType, res):
        '''Gets, in p_res ~{'css':[s_css], 'js':[s_js]}~ the lists of
           Javascript and CSS files required by Appy types p_fields when shown
           on p_layoutType.'''
        # Lists css and js below are not sets, because order of Javascript
        # inclusion can be important, and this could be losed by using sets.
        css = []
        js = []
        config = self.getProductConfig(True)
        for field in fields:
            field.getCss(layoutType, css, config)
            field.getJs(layoutType, js, config)
        res['css'] = css
        res['js'] = js

    def getCssFor(self, elem):
        '''Gets the name of the CSS class to use for styling some p_elem. If
           self's class does not define a dict "styles", the defaut CSS class
           to use will be named p_elem.'''
        klass = self.getClass()
        if hasattr(klass, 'styles') and (elem in klass.styles):
            return klass.styles[elem]
        return elem

    def getAppyPhases(self, currentOnly=False, layoutType='view'):
        '''Gets the list of phases that are defined for this content type. If
           p_currentOnly is True, the search is limited to the phase where the
           current page (as defined in the request) lies.'''
        # Get the list of phases
        res = [] # Ordered list of phases
        phases = {} # Dict of phases
        for field in self.getAllAppyTypes():
            fieldPhase = field.page.phase
            if fieldPhase not in phases:
                phase = gen.Phase(fieldPhase, self)
                res.append(phase)
                phases[fieldPhase] = phase
            else:
                phase = phases[fieldPhase]
            phase.addPage(field, self, layoutType)
            if (field.type == 'Ref') and field.navigable:
                phase.addPageLinks(field, self)
        # Remove phases that have no visible page
        for i in range(len(res)-1, -1, -1):
            if not res[i].pages:
                del phases[res[i].name]
                del res[i]
        # Compute next/previous phases of every phase
        for ph in phases.itervalues():
            ph.computeNextPrevious(res)
            ph.totalNbOfPhases = len(res)
        # Restrict the result to the current phase if required
        if currentOnly:
            rq = self.REQUEST
            page = rq.get('page', None)
            if not page:
                if layoutType == 'edit': page = self.getDefaultEditPage()
                else:                    page = self.getDefaultViewPage()
            for phase in res:
                if page in phase.pages:
                    return phase
            # If I am here, it means that the page as defined in the request,
            # or the default page, is not existing nor visible in any phase.
            # In this case I find the first visible page among all phases.
            viewAttr = 'showOn%s' % layoutType.capitalize()
            for phase in res:
                for page in phase.pages:
                    if getattr(phase.pagesInfo[page], viewAttr):
                        rq.set('page', page)
                        pageFound = True
                        break
            return phase
        else:
            # Return an empty list if we have a single, link-free page within
            # a single phase.
            if (len(res) == 1) and (len(res[0].pages) == 1) and \
               not res[0].pagesInfo[res[0].pages[0]].links:
                return
            return res

    def highlight(self, text):
        '''This method highlights parts of p_value if we are in the context of
           a query whose keywords must be highlighted.'''
        # Must we highlight something?
        criteria = self.REQUEST.SESSION.get('searchCriteria')
        if not criteria or ('SearchableText' not in criteria): return text
        # Highlight every variant of every keyword
        for word in criteria['SearchableText'].strip().split():
            sWord = word.strip(' *').lower()
            for variant in (sWord, sWord.capitalize(), sWord.upper()):
                text = text.replace(variant, '***+%s-***' % variant)
                # If I replace immediately with the opening and ending "span"
                # tag (see below), I will have problems if the next keyword is
                # included in the tag, ie "la" (in 'class', or "spa" (in
                # 'span').
        text = text.replace('***+', '<span class="highlight">')
        return text.replace('-***', '</span>')

    def getSupTitle(self, navInfo=''):
        '''Gets the html code (icons,...) that can be shown besides the title
           of an object.'''
        obj = self.appy()
        if hasattr(obj, 'getSupTitle'): return obj.getSupTitle(navInfo)
        return ''

    def getSubTitle(self):
        '''Gets the content that must appear below the title of an object.'''
        obj = self.appy()
        if hasattr(obj, 'getSubTitle'): return obj.getSubTitle()
        return ''

    def getSupBreadCrumb(self):
        '''Gets the html code that can be shown besides the title of an object
           in the breadcrumb.'''
        obj = self.appy()
        if hasattr(obj, 'getSupBreadCrumb'): return obj.getSupBreadCrumb()
        return ''

    def getSubBreadCrumb(self):
        '''Gets the content that must appear below the title of an object in the
           breadcrumb.'''
        obj = self.appy()
        if hasattr(obj, 'getSubBreadCrumb'): return obj.getSubBreadCrumb()
        return ''

    def getListTitle(self, mode='link', nav='', target=None, page='main',
                     inPopup=False, selectJs=None, highlight=False):
        '''Gets the title as it must appear in lists of objects (ie in lists of
           tied objects in a Ref, in query results...).

           In most cases, a title must appear as a link that leads to the object
           view layout. In this case (p_mode == "link"):
           * p_nav     is the navigation parameter allowing navigation between
                       this object and others;
           * p_target  specifies if the link must be opened in the popup or not;
           * p_page    specifies which page to show on the target object view;
           * p_inPopup indicates if we are already in the popup or not.

           Another p_mode is "select". In this case, we are in a popup for
           selecting objects: every title must not be a link, but clicking on it
           must trigger Javascript code (in p_selectJs) that will select this
           object.

           The last p_mode is "text". In this case, we simply show the object
           title but with no tied action (link, select).

           If p_highlight is True, keywords will be highlighted if we are in the
           context of a query with keywords.
        '''
        # Compute common parts
        cssClass = self.getCssFor('title')
        # Get the title, with highlighted parts when relevant
        title = self.getShownValue('title')
        if highlight: title = self.highlight(title)
        if mode == 'link':
            inPopup = inPopup or (target.target != '_self')
            url = self.getUrl(page=page, nav=nav, inPopup=inPopup)
            onClick = target.openPopup or 'clickOn(this)'
            res = '<a href="%s" class="%s" onclick="%s" target="%s">%s</a>' % \
                  (url, cssClass, onClick, target.target, title)
        elif mode == 'select':
            res = '<span class="%s clickable" onclick="%s">%s</span>' % \
                  (cssClass, selectJs, title)
        elif mode == 'text':
            res = '<span class="%s">%s</span>' % (cssClass, title)
        return res

    # Workflow methods ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    def initializeWorkflow(self):
        '''Called when an object is created, be it temp or not, for initializing
           workflow-related data on the object.'''
        wf = self.getWorkflow()
        # Get the initial workflow state
        initialState = self.State(name=False)
        # Create a Transition instance representing the initial transition
        initialTransition = gen.Transition((initialState, initialState))
        initialTransition.trigger('_init_', self, wf, '', doSay=False)

    def getWorkflow(self, name=False, className=None):
        '''Returns the workflow applicable for p_self (or for any instance of
           p_className if given), or its name, if p_name is True.'''
        if not className:
            wrapperClass = self.wrapperClass
        else:
            wrapperClass = self.getTool().getAppyClass(className, wrapper=True)
        wf = wrapperClass.getWorkflow()
        if not name: return wf
        return WorkflowDescriptor.getWorkflowName(wf)

    def getWorkflowLabel(self, name=None):
        '''Gets the i18n label for p_name (which can denote a state or a
           transition), or for the current object state if p_name is None.'''
        name = name or self.State()
        if name == 'create_from_predecessor': return name
        return '%s_%s' % (self.getWorkflow(name=True), name)

    def getTransitions(self, includeFake=True, includeNotShowable=False,
                       grouped=True):
        '''This method returns info about transitions (as UiTransition
           instances) that one can trigger from the user interface.
           * if p_includeFake is True, it retrieves transitions that the user
             can't trigger, but for which he needs to know for what reason he
             can't trigger it;
           * if p_includeNotShowable is True, it includes transitions for which
             show=False. Indeed, because "showability" is only a UI concern,
             and not a security concern, in some cases it has sense to set
             includeNotShowable=True, because those transitions are triggerable
             from a security point of view.
           * If p_grouped is True, transitions are grouped according to their
             "group" attribute, in a similar way to fields or searches.
        '''
        res = []
        groups = {} # The already encountered groups of transitions.
        wfPage = gen.Page('workflow')
        wf = self.getWorkflow()
        currentState = self.State(name=False)
        # Loop on every transition
        for name in dir(wf):
            transition = getattr(wf, name)
            if (transition.__class__.__name__ != 'Transition'): continue
            # Filter transitions that do not have currentState as start state
            if not transition.hasState(currentState, True): continue
            # Check if the transition can be triggered
            mayTrigger = transition.isTriggerable(self, wf)
            # Compute the condition that will lead to including or not this
            # transition
            if not includeFake:
                includeIt = mayTrigger
            else:
                includeIt = mayTrigger or isinstance(mayTrigger, gen.No)
            if not includeNotShowable:
                includeIt = includeIt and transition.isShowable(wf, self)
            if not includeIt: continue
            # Create the UiTransition instance.
            info = UiTransition(name, transition, self, mayTrigger)
            # Add the transition into the result.
            if not transition.group or not grouped:
                res.append(info)
            else:
                # Insert the UiGroup instance corresponding to transition.group.
                uiGroup = transition.group.insertInto(res, groups, wfPage,
                                 self.__class__.__name__, content='transitions')
                uiGroup.addElement(info)
        return res

    def applyUserIdChange(self, oldId, newId):
        '''A user whose ID was p_oldId has now p_newId. If the old ID was
           mentioned in self's local roles, update it to the new ID. This
           method returns 1 if a change occurred, 0 else.'''
        if oldId in self.__ac_local_roles__:
            localRoles = self.__ac_local_roles__.copy()
            localRoles[newId] = localRoles[oldId]
            del localRoles[oldId]
            self.__ac_local_roles__ = localRoles
            self.reindex()
            return 1
        return 0

    def findNewValue(self, field, language, history, stopIndex):
        '''This function tries to find a more recent version of value of p_field
           on p_self. In the case of a multilingual field, p_language is
           specified. The method first tries to find it in
           history[:stopIndex+1]. If it does not find it there, it returns the
           current value on p_obj.'''
        i = stopIndex + 1
        name = language and ('%s-%s' % (field.name, language)) or field.name
        while (i-1) >= 0:
            i -= 1
            if history[i]['action'] != '_datachange_': continue
            if name not in history[i]['changes']: continue
            # We have found it!
            return history[i]['changes'][name][0] or ''
        # A most recent version was not found in the history: return the current
        # field value.
        val = field.getValue(self)
        if not language: return val or ''
        return val and val.get(language) or ''

    def getHistoryTexts(self, event):
        '''Returns a tuple (insertText, deleteText) containing texts to show on,
           respectively, inserted and deleted chunks of text in a XHTML diff.'''
        tool = self.getTool()
        mapping = {'userName': tool.getUserName(event['actor'])}
        res = []
        for type in ('insert', 'delete'):
            msg = self.translate('history_%s' % type, mapping=mapping)
            date = tool.formatDate(event['time'], withHour=True)
            msg = '%s: %s' % (date, msg)
            res.append(msg)
        return res

    def hasHistory(self, name=None):
        '''Has this object an history? If p_name is specified, the question
           becomes: has this object an history for field p_name?'''
        if not hasattr(self.aq_base, 'workflow_history') or \
           not self.workflow_history: return
        # Return False if the user can't consult the object history
        klass = self.getClass()
        if hasattr(klass, 'showHistory'):
            show = klass.showHistory
            if callable(show): show = klass.showHistory(self.appy())
            if not show: return
        # Get the object history
        history = self.workflow_history['appy']
        if not name:
            for event in history:
                if event['action'] and (event['comments'] != '_invisible_'):
                    return True
        else:
            field = self.getAppyType(name)
            # Is this field a multilingual field ?
            languages = None
            if field.type == 'String':
                languages = field.getAttribute(self, 'languages')
            multilingual = len(languages) > 1
            for event in history:
                if event['action'] != '_datachange_': continue
                # Is there a value present for this field in this data change?
                if not multilingual:
                    if (name in event['changes']) and \
                       (event['changes'][name][0]):
                        return True
                else:
                    # At least one language-specific value must be present
                    for lg in languages:
                        lgName = '%s-%s' % (field.name, lg)
                        if (lgName in event['changes']) and \
                           event['changes'][lgName][0]:
                            return True

    def getHistory(self, startNumber=0, reverse=True, includeInvisible=False,
                   batchSize=5):
        '''Returns a copy of the history for this object, sorted in p_reverse
           order if specified (most recent change first), whose invisible events
           have been removed if p_includeInvisible is True.'''
        history = list(self.workflow_history['appy'][1:])
        if not includeInvisible:
            history = [e for e in history if e['comments'] != '_invisible_']
        if reverse: history.reverse()
        # Keep only events which are within the batch
        res = []
        stopIndex = startNumber + batchSize - 1
        i = -1
        while (i+1) < len(history):
            i += 1
            # Ignore events outside range startNumber:startNumber+batchSize
            if i < startNumber: continue
            if i > stopIndex: break
            if history[i]['action'] == '_datachange_':
                # Take a copy of the event: we will modify it and replace
                # fields' old values by their formatted counterparts.
                event = history[i].copy()
                event['changes'] = {}
                for name, oldValue in history[i]['changes'].iteritems():
                    # "name" can specify a language-specific part in a
                    # multilingual field. "oldValue" is a tuple
                    # (value, fieldName).
                    if '-' in name:
                        fieldName, lg = name.split('-')
                    else:
                        fieldName = name
                        lg = None
                    field = self.getAppyType(fieldName)
                    # Field 'name' may not exist, if the history has been
                    # transferred from another site. In this case we can't show
                    # this data change.
                    if not field: continue
                    if (field.type == 'String') and \
                       (field.format == gen.String.XHTML):
                        # For rich text fields, instead of simply showing the
                        # previous value, we propose a diff with the next
                        # version, excepted if the previous value is empty.
                        if lg: isEmpty = not oldValue[0]
                        else: isEmpty = field.isEmptyValue(self, oldValue[0])
                        if isEmpty:
                            val = '-'
                        else:
                            newValue= self.findNewValue(field, lg, history, i-1)
                            # Compute the diff between oldValue and newValue
                            iMsg, dMsg = self.getHistoryTexts(event)
                            comparator= HtmlDiff(oldValue[0],newValue,iMsg,dMsg)
                            val = comparator.get()
                    else:
                        fmt = lg and 'getUnilingualFormattedValue' or \
                                     'getFormattedValue'
                        val = getattr(field, fmt)(self, oldValue[0]) or '-'
                        if isinstance(val, list) or isinstance(val, tuple):
                            val = '<ul>%s</ul>' % \
                                  ''.join(['<li>%s</li>' % v for v in val])
                    event['changes'][name] = (val, oldValue[1])
            else:
                event = history[i]
            res.append(event)
        return Object(events=res, totalNumber=len(history))

    def getHistoryCollapse(self):
        '''Gets a Collapsible instance for showing a collapse or expanded
           history in this object.'''
        return Collapsible('objectHistory', self.REQUEST)

    def getHistoryAjaxData(self, hook, startNumber, batchSize):
        '''Gets data allowing to ajax-ask paginated history data.'''
        params = {'startNumber': startNumber, 'maxPerPage': batchSize}
        # Convert params into a JS dict
        params = sutils.getStringDict(params)
        return "getAjaxHook('%s',true)['ajax']=new AjaxData('%s','pxHistory', "\
               "%s, null, '%s')" % (hook, hook, params, self.absolute_url())

    def mayNavigate(self):
        '''May the currently logged user see the navigation panel linked to
           this object?'''
        appyObj = self.appy()
        if hasattr(appyObj, 'mayNavigate'): return appyObj.mayNavigate()
        return True

    def getDefaultViewPage(self):
        '''Which view page must be shown by default?'''
        appyObj = self.appy()
        if hasattr(appyObj, 'getDefaultViewPage'):
            return appyObj.getDefaultViewPage()
        return 'main'

    def getDefaultEditPage(self):
        '''Which edit page must be shown by default?'''
        appyObj = self.appy()
        if hasattr(appyObj, 'getDefaultEditPage'):
            return appyObj.getDefaultEditPage()
        return 'main'

    def mayAct(self):
        '''m_mayAct allows to hide the whole set of actions for an object.
           Indeed, beyond workflow security, it can be useful to hide controls
           like "edit" icons/buttons. For example, if a user may only edit some
           Ref fields with add=True on an object, when clicking on "edit", he
           will see an empty edit form.'''
        appyObj = self.appy()
        if hasattr(appyObj, 'mayAct'): return appyObj.mayAct()
        return True

    def mayDelete(self):
        '''May the currently logged user delete this object?'''
        res = self.allows('delete')
        if not res: return
        # An additional, user-defined condition, may refine the base permission.
        appyObj = self.appy()
        if hasattr(appyObj, 'mayDelete'): return appyObj.mayDelete()
        return True

    def mayEdit(self, permission='write', permOnly=False, raiseError=False):
        '''May the currently logged user edit this object? p_permission can be a
           field-specific permission. If p_permOnly is True, the specific
           user-defined condition is not evaluated. If p_raiseError is True, if
           the user may not edit p_self, an error is raised.'''
        res = self.allows(permission, raiseError=raiseError)
        if not res: return
        if permOnly: return res
        # An additional, user-defined condition, may refine the base permission.
        appyObj = self.appy()
        if hasattr(appyObj, 'mayEdit'):
            res = appyObj.mayEdit()
            if not res and raiseError: self.raiseUnauthorized()
            return res
        return True

    def mayView(self, permission='read', raiseError=False):
        '''May the currently logged user view this object? p_permission can be a
           field-specific permission. If p_raiseError is True, if the user may
           not view p_self, an error is raised.'''
        res = self.allows(permission, raiseError=raiseError)
        if not res: return
        # An additional, user-defined condition, may refine the base permission.
        appyObj = self.appy()
        if hasattr(appyObj, 'mayView'):
            res = appyObj.mayView()
            if not res and raiseError: self.raiseUnauthorized()
            return res
        return True

    def onExecuteAction(self):
        '''Called when a user wants to execute an Appy action on an object.'''
        rq = self.REQUEST
        return self.getAppyType(rq['fieldName']).onUiRequest(self, rq)

    def onTrigger(self):
        '''Called when a user wants to trigger a transition on an object.'''
        rq = self.REQUEST
        wf = self.getWorkflow()
        # Get the transition
        name = rq['transition']
        transition = getattr(wf, name, None)
        if not transition or (transition.__class__.__name__ != 'Transition'):
            raise Exception('Transition "%s" not found.' % name)
        return transition.onUiRequest(self, wf, name, rq)

    def getRolesFor(self, permission):
        '''Gets, according to the workflow, the roles that are currently granted
           p_permission on this object.'''
        state = self.State(name=False)
        if permission not in state.permissions:
            wf = self.getWorkflow().__name__
            raise Exception('Permission "%s" not in permissions dict for ' \
                            'state %s.%s' % \
                            (permission, wf, self.State(name=True)))
        roles = state.permissions[permission]
        if roles: return [role.name for role in roles]
        return ()

    def appy(self):
        '''Returns a wrapper object allowing to manipulate p_self the Appy
           way.'''
        # Create the dict for storing Appy wrapper on the REQUEST if needed.
        rq = getattr(self, 'REQUEST', None)
        if not rq:
            # We are in test mode or Zope is starting. Use static variable
            # config.fakeRequest instead.
            rq = self.getProductConfig().fakeRequest
        if not hasattr(rq, 'wrappers'): rq.wrappers = {}
        # Return the Appy wrapper if already present in the cache
        uid = self.id
        if uid in rq.wrappers: return rq.wrappers[uid]
        # Create the Appy wrapper, cache it in rq.wrappers and return it
        wrapper = self.wrapperClass(self)
        rq.wrappers[uid] = wrapper
        return wrapper

    # --------------------------------------------------------------------------
    # Methods for computing values of standard Appy indexes
    # --------------------------------------------------------------------------
    def UID(self):
        '''Returns the unique identifier for this object.'''
        return self.id

    def Title(self):
        '''Returns the title for this object.'''
        title = self.getAppyType('title')
        if title: return title.getIndexValue(self)
        return self.id

    def SortableTitle(self):
        '''Returns the title as must be stored in index "SortableTitle".'''
        return sutils.normalizeText(self.Title())

    def SearchableText(self):
        '''This method concatenates the content of every field with
           searchable=True for indexing purposes.'''
        res = []
        for field in self.getAllAppyTypes():
            if not field.searchable: continue
            res.append(field.getIndexValue(self, forSearch=True))
        return res

    def Creator(self):
        '''Who create this object?'''
        return self.creator

    def Created(self):
        '''When was this object created ?'''
        return self.created

    def Modified(self):
        '''When was this object last modified ?'''
        if hasattr(self.aq_base, 'modified'): return self.modified
        return self.created

    def State(self, name=True, initial=False):
        '''Returns information about the current object state. If p_name is
           True, the returned info is the state name. Else, it is the State
           instance. If p_initial is True, instead of returning info about the
           current state, it returns info about the workflow initial state.'''
        wf = self.getWorkflow()
        if initial or not hasattr(self.aq_base, 'workflow_history'):
            # No workflow information is available (yet) on this object, or
            # initial state is asked. In both cases, return info about this
            # initial state.
            res = 'active'
            for elem in dir(wf):
                attr = getattr(wf, elem)
                if (attr.__class__.__name__ == 'State') and attr.initial:
                    res = elem
                    break
        else:
            # Return info about the current object state
            res = self.workflow_history['appy'][-1]['review_state']
        # Return state name or state definition?
        if name: return res
        else: return getattr(wf, res)

    def ClassName(self):
        '''Returns the name of the (Zope) class for self.'''
        return self.portal_type

    def Allowed(self):
        '''Returns the list of roles and users that are allowed to view this
           object. This index value will be used within catalog queries for
           filtering objects the user is allowed to see.'''
        # Get, from the workflow, roles having permission 'read'.
        res = self.getRolesFor('read')
        # Add users or groups having, locally, this role on this object.
        localRoles = getattr(self.aq_base, '__ac_local_roles__', None)
        if not localRoles: return res
        for id, roles in localRoles.iteritems():
            for role in roles:
                if role in res:
                    usr = 'user:%s' % id
                    if usr not in res: res.append(usr)
        return res

    def showState(self):
        '''Must I show self's current state ?'''
        stateShow = self.State(name=False).show
        if callable(stateShow):
            return stateShow(self.getWorkflow(), self.appy())
        return stateShow

    def showTransitions(self, layoutType):
        '''Must we show the buttons/icons for triggering transitions on
           p_layoutType?'''
        # Never show transitions on edit pages.
        if layoutType == 'edit': return
        # Use the default value if self's class does not specify it.
        klass = self.getClass()
        if not hasattr(klass, 'showTransitions'): return (layoutType=='view')
        showValue = klass.showTransitions
        # This value can be a single value or a tuple/list of values.
        if isinstance(showValue, basestring): return layoutType == showValue
        return layoutType in showValue

    getUrlDefaults = {'page':True, 'nav':True}
    def getUrl(self, base=None, mode='view', inPopup=False, relative=False,
               **kwargs):
        '''Returns an URL for this object.
           * If p_base is None, it will be the base URL for this object
             (ie, Zope self.absolute_url() or an URL this is relative to the
             root site if p_relative is True).
           * p_mode can be "edit", "view" or "raw" (a non-param, base URL)
           * If p_inPopup is True, the link will be opened in the Appy iframe.
             An additional param "popup=1" will be added to URL params, in order
             to tell Appy that the link target will be shown in a popup, in a
             minimalistic way (no portlet...).
           * p_kwargs can store additional parameters to add to the URL.
             In this dict, every value that is a string will be added to the
             URL as-is. Every value that is True will be replaced by the value
             in the request for the corresponding key (if existing; else, the
             param will not be included in the URL at all).'''
        # Define the URL suffix
        suffix = ''
        if mode != 'raw': suffix = '/%s' % mode
        # Define the base URL if omitted
        if not base:
            base = relative and self.absolute_url_path() or self.absolute_url()
            base += suffix
            existingParams = ''
        else:
            existingParams = urllib.splitquery(base)[1]
        # If a raw URL is asked, remove any param and suffix
        if mode == 'raw':
            if '?' in base: base = base[:base.index('?')]
            base = base.rstrip('/')
            for mode in ('view', 'edit'):
                if base.endswith(mode):
                    base = base[:-len(mode)].rstrip('/')
                    break
            return base
        # Manage default args
        if not kwargs: kwargs = self.getUrlDefaults
        if 'page' not in kwargs: kwargs['page'] = True
        if 'nav'  not in kwargs: kwargs['nav'] = True
        # Create URL parameters from kwargs
        params = []
        for name, value in kwargs.iteritems():
            if isinstance(value, basestring):
                params.append('%s=%s' % (name, value))
            elif self.REQUEST.get(name, ''):
                params.append('%s=%s' % (name, self.REQUEST[name]))
        # Manage inPopup
        if inPopup and ('popup=' not in existingParams):
            params.append('popup=1')
        if params:
            params = '&'.join(params)
            if base.find('?') != -1: params = '&' + params
            else:                    params = '?' + params
        else:
            params = ''
        return '%s%s' % (base, params)

    def getTool(self):
        '''Returns the application tool.'''
        return self.getPhysicalRoot().config

    def getProductConfig(self, app=False):
        '''Returns a reference to the config module. If p_app is True, it
           returns the application config.'''
        res = self.__class__.config
        if app: res = res.appConfig
        return res

    def getParent(self):
        '''If this object is stored within another one, this method returns it.
           Else (if the object is stored directly within the tool or the root
           data folder) it returns None.'''
        parent = self.getParentNode()
        # Not-Managers can't navigate back to the tool
        if (parent.id == 'config') and \
            not self.getTool().getUser().has_role('Manager'):
            return False
        if parent.meta_type not in ('Folder', 'Temporary Folder'): return parent

    def getShownValue(self, name='title', language=None):
        '''Call field.getShownValue on field named p_name.'''
        field = self.getAppyType(name)
        return field.getShownValue(self, field.getValue(self),
                                   language=language)

    def getBreadCrumb(self, inPopup=False):
        '''Gets breadcrumb info about this object and its parents (if it must
           be shown).'''
        # Return an empty breadcrumb if it must not be shown.
        klass = self.getClass()
        if hasattr(klass, 'breadcrumb') and not klass.breadcrumb: return ()
        # Compute the breadcrumb
        title = self.getAppyType('title')
        res = [Object(url=self.getUrl(inPopup=inPopup),
                      title=title.getShownValue(self, title.getValue(self)))]
        # In a popup: limit the breadcrumb to the current object.
        if inPopup: return res
        parent = self.getParent()
        if parent: res = parent.getBreadCrumb() + res
        return res

    def index_html(self):
        '''Base method called when hitting this object.
           - The standard behaviour is to redirect to /view.
           - If a parameter named "do" is present in the request, it is supposed
             to contain the name of a method to call on this object. In this
             case, we call this method and return its result as XML.
           - If method is POST, we consider the request to be XML data, that we
             marshall to Python, and we call the method in param "do" with, as
             arg, this marshalled Python object. While this could sound strange
             to expect a query string containing a param "do" in a HTTP POST,
             the HTTP spec does not prevent to do it.'''
        rq = self.REQUEST
        if (rq.REQUEST_METHOD == 'POST') and rq.QUERY_STRING:
            # A POST method containing XML data.
            rq.args = XmlUnmarshaller().parse(rq.stdin.getvalue())
            # Find the name of the method to call.
            methodName = rq.QUERY_STRING.split('=')[1]
            return self.xml(action=methodName)
        elif rq.has_key('do'):
            # The user wants to call a method on this object and get its result
            # as XML.
            return self.xml(action=rq['do'])
        else:
            # The user wants to consult the view page for this object
            return rq.RESPONSE.redirect(self.getUrl())

    def getUserLanguage(self):
        '''Gets the language (code) of the current user.'''
        if not hasattr(self, 'REQUEST'):
            return self.getProductConfig().appConfig.languages[0]
        # Return the cached value on the request object if present
        rq = self.REQUEST
        if hasattr(rq, 'userLanguage'): return rq.userLanguage
        # Try the value which comes from the cookie. Indeed, if such a cookie is
        # present, it means that the user has explicitly chosen this language
        # via the language selector.
        if '_ZopeLg' in rq.cookies:
            res = rq.cookies['_ZopeLg']
        else:
            # Try the LANGUAGE key from the request: it corresponds to the
            # language as configured in the user's browser.
            res = rq.get('LANGUAGE', None)
            if not res:
                # Try the HTTP_ACCEPT_LANGUAGE key from the request, which
                # stores language preferences as defined in the user's browser.
                # Several languages can be listed, from most to less wanted.
                res = rq.get('HTTP_ACCEPT_LANGUAGE', None)
                if res:
                    if ',' in res: res = res[:res.find(',')]
                    if '-' in res: res = res[:res.find('-')]
                else:
                    res = self.getProductConfig().appConfig.languages[0]
        # Cache this result
        rq.userLanguage = res
        return res

    def getLanguageDirection(self, lang):
        '''Determines if p_lang is a LTR or RTL language.'''
        if lang in rtlLanguages: return 'rtl'
        return 'ltr'

    def formatText(self, text, format='html'):
        '''Produces a representation of p_text into the desired p_format, which
           is "html" by default.'''
        if 'html' in format:
            if format == 'html_from_text': text = cgi.escape(text)
            res = text.replace('\r\n', '<br/>').replace('\n', '<br/>')
        elif format == 'text':
            res = text.replace('<br/>', '\n')
        else:
            res = text
        return res

    def translate(self, label, mapping={}, domain=None, default=None,
                  language=None, format='html', field=None):
        '''Translates a given p_label into p_domain with p_mapping.

           If p_field is given, p_label does not correspond to a full label
           name, but to a label type linked to p_field: "label", "descr"
           or "help". Indeed, in this case, a specific i18n mapping may be
           available on the field, so we must merge this mapping into
           p_mapping.'''
        cfg = self.getProductConfig()
        if not domain: domain = cfg.PROJECTNAME
        # Get the label name, and the field-specific mapping if any.
        if field:
            if field.type != 'group':
                fieldMapping = field.mapping[label]
                if fieldMapping:
                    if callable(fieldMapping):
                        fieldMapping = field.callMethod(self, fieldMapping)
                    mapping.update(fieldMapping)
            label = getattr(field, '%sId' % label)
        # We will get the translation from a Translation object.
        # In what language must we get the translation?
        if not language: language = self.getUserLanguage()
        tool = self.getTool()
        try:
            translation = getattr(tool, language).appy()
        except AttributeError:
            # We have no translation for this language. Fallback to 'en'.
            translation = getattr(tool, 'en').appy()
        res = getattr(translation, label, '')
        if not res:
            # Fallback to 'en'.
            translation = getattr(tool, 'en').appy()
            res = getattr(translation, label, '')
        # If still no result, put a nice name derived from the label instead of
        # a translated message.
        if not res: res = produceNiceMessage(label.rsplit('_', 1)[-1])
        else:
            # Perform replacements, according to p_format.
            res = self.formatText(res, format)
            # Perform variable replacements
            for name, repl in mapping.iteritems():
                if not isinstance(repl, basestring): repl = str(repl)
                res = res.replace('${%s}' % name, repl)
        return res

    def getPageLayout(self, layoutType):
        '''Returns the layout corresponding to p_layoutType for p_self.'''
        res = self.wrapperClass.getPageLayouts()[layoutType]
        if isinstance(res, basestring): res = Table(res)
        return res

    def download(self, name=None):
        '''Downloads the content of the file that is in the File field whose
           name is in the request. This name can also represent an attribute
           storing an image within a rich text field. If p_name is not given, it
           is retrieved from the request.'''
        rq = self.REQUEST
        name = rq.get('name')
        if not name: return
        # Security check
        if '_img_' not in name:
            field = self.getAppyType(name)
        else:
            field = self.getAppyType(name.split('_img_')[0])
        self.mayView(field.readPermission, raiseError=True)
        # Write the file in the HTTP response
        info = getattr(self.aq_base, name, None)
        if info:
            # Content disposition may be given in the request
            disposition = rq.get('disposition', 'attachment')
            if disposition not in ('inline', 'attachment'):
                disposition = 'attachment'
            info.writeResponse(rq.RESPONSE, self.getDbFolder(), disposition)

    def upload(self):
        '''Receives an image uploaded by the user via ckeditor and stores it in
           a special field on this object.'''
        # Get the name of the rich text field for which an image must be stored.
        params = self.REQUEST['QUERY_STRING'].split('&')
        fieldName = params[0].split('=')[1]
        ckNum = params[1].split('=')[1]
        # We will store the image in a field named [fieldName]_img_[nb].
        i = 1
        attrName = '%s_img_%d' % (fieldName, i)
        while True:
            if not hasattr(self.aq_base, attrName):
                break
            else:
                i += 1
                attrName = '%s_img_%d' % (fieldName, i)
        # Store the image. Create a fake File instance for doing the job.
        fakeFile = gen.File(isImage=True)
        fakeFile.name = attrName
        fakeFile.store(self, self.REQUEST['upload'])
        # Return the URL of the image.
        url = '%s/download?name=%s' % (self.absolute_url(), attrName)
        response = self.REQUEST.RESPONSE
        response.setHeader('Content-Type', 'text/html')
        resp = "<script type='text/javascript'>window.parent.CKEDITOR.tools" \
               ".callFunction(%s, '%s');</script>" % (ckNum, url)
        response.write(resp)

    def allows(self, permission, raiseError=False):
        '''Has the logged user p_permission on p_self ?'''
        res = self.getTool().getUser().has_permission(permission, self)
        if not res and raiseError: self.raiseUnauthorized()
        return res

    def isTemporary(self):
        '''Is this object temporary ?'''
        parent = self.getParentNode()
        if not parent: return # Is probably being created through code
        return parent.getId() == 'temp_folder'

    def onProcess(self):
        '''This method is a general hook for transfering processing of a request
           to a given field, whose name must be in the request.'''
        return self.getAppyType(self.REQUEST['name']).process(self)

    def onCall(self):
        '''Calls a specific method on the corresponding wrapper.'''
        self.mayView(raiseError=True)
        method = self.REQUEST['method']
        obj = self.appy()
        return getattr(obj, method)()

    def onReindex(self):
        '''Called for reindexing an index or all indexes on the currently shown
           object.'''
        if not self.getTool().getUser().has_role('Manager'):
            self.raiseUnauthorized()
        rq = self.REQUEST
        indexName = rq['indexName']
        if indexName == '_all_':
            self.reindex()
        else:
            self.reindex(indexes=(indexName,))
        self.say(self.translate('action_done'))
        self.goto(self.getUrl(rq['HTTP_REFERER']))
# ------------------------------------------------------------------------------