appypod-rattail/pod/elements.py
2013-06-25 12:04:23 +02:00

189 lines
7.9 KiB
Python

# ------------------------------------------------------------------------------
# This file is part of Appy, a framework for building applications in the Python
# language. Copyright (C) 2007 Gaetan Delannay
# Appy is free software; you can redistribute it and/or modify it under the
# terms of the GNU General Public License as published by the Free Software
# Foundation; either version 3 of the License, or (at your option) any later
# version.
# Appy is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE. See the GNU General Public License for more details.
# You should have received a copy of the GNU General Public License along with
# Appy. If not, see <http://www.gnu.org/licenses/>.
# ------------------------------------------------------------------------------
from xml.sax.saxutils import quoteattr
from appy.shared.xml_parser import XmlElement
from appy.pod.odf_parser import OdfEnvironment as ns
from appy.pod import PodError
# ------------------------------------------------------------------------------
class PodElement:
OD_TO_POD = {'p': 'Text', 'h': 'Title', 'section': 'Section',
'table': 'Table', 'table-row': 'Row', 'table-cell': 'Cell',
None: 'Expression'}
POD_ELEMS = ('text', 'title', 'section', 'table', 'row', 'cell')
# Elements for which the '-' operator can be applied.
MINUS_ELEMS = ('section', 'table')
@staticmethod
def create(elem):
'''Used to create any POD elem that has an equivalent OD element. Not
for creating expressions, for example.'''
return eval(PodElement.OD_TO_POD[elem])()
class Text(PodElement):
OD = XmlElement('p', nsUri=ns.NS_TEXT)
# When generating an error we may need to surround it with a given tag and
# sub-tags.
subTags = []
class Title(PodElement):
OD = XmlElement('h', nsUri=ns.NS_TEXT)
subTags = []
class Section(PodElement):
OD = XmlElement('section', nsUri=ns.NS_TEXT)
subTags = [Text.OD]
# When we must remove the Section element from a buffer, the deepest element
# to remove is the Section element itself.
DEEPEST_TO_REMOVE = OD
class Cell(PodElement):
OD = XmlElement('table-cell', nsUri=ns.NS_TABLE)
subTags = [Text.OD]
def __init__(self):
self.tableInfo = None # ~OdTable~
self.colIndex = None # The column index for this cell, within its table.
class Row(PodElement):
OD = XmlElement('table-row', nsUri=ns.NS_TABLE)
subTags = [Cell.OD, Text.OD]
class Table(PodElement):
OD = XmlElement('table', nsUri=ns.NS_TABLE)
subTags = [Row.OD, Cell.OD, Text.OD]
# When we must remove the Table element from a buffer, the deepest element
# to remove is the Cell (it can only be done for one-row, one-cell tables).
DEEPEST_TO_REMOVE = Cell.OD
def __init__(self):
self.tableInfo = None # ~OdTable~
class Expression(PodElement):
'''Represents a Python expression that is found in a pod or px.'''
OD = None
def __init__(self, pyExpr, pod):
# The Python expression
self.expr = pyExpr.strip()
self.pod = pod # True if I work for pod, False if I work for px.
# Must we, when evaluating the expression, escape XML special chars
# or not?
if self.expr.startswith(':'):
self.expr = self.expr[1:]
self.escapeXml = False
else:
self.escapeXml = True
if self.pod:
# pod-only: store here the expression's true result (before being
# converted to a string).
self.result = None
# pod-only: the following bool indicates if this Expression instance
# has already been evaluated or not. Expressions which are tied to
# attribute hooks are already evaluated when the tied hook is
# evaluated: this boolean prevents the expression from being
# evaluated twice.
self.evaluated = False
# self.result and self.evaluated are not used by PX, because they
# are not thread-safe.
def evaluate(self, context):
'''Evaluates the Python expression (self.expr) with a given
p_context, and returns the result. More precisely, it returns a
tuple (result, escapeXml). Boolean escapeXml indicates if XML chars
must be escaped or not.'''
escapeXml = self.escapeXml
# Evaluate the expression, or get it from self.result if it has already
# been computed.
if self.pod and self.evaluated:
res = self.result
# It can happen only once, to ask to evaluate an expression that
# was already evaluated (from the tied hook). We reset here the
# boolean "evaluated" to allow for the next evaluation, probably
# with another context.
self.evaluated = False
else:
# Evaluates the Python expression
res = eval(self.expr, context)
# pod-only: cache the expression result.
if self.pod: self.result = res
# Converts the expr result to a string that can be inserted in the
# pod/px result.
resultType = res.__class__.__name__
if resultType == 'NoneType':
res = u''
elif resultType == 'str':
res = res.decode('utf-8')
elif resultType == 'unicode':
pass # Don't perform any conversion, unicode is the target type.
elif resultType == 'Px':
# A PX that must be called within the current PX. Call it with the
# current context.
res = res(context, applyTemplate=False)
# Force escapeXml to False.
escapeXml = False
else:
res = unicode(res)
return res, escapeXml
class Attributes(PodElement):
'''Represents a bunch of XML attributes that will be dumped for a given tag
in the result. pod-only.'''
OD = None
floatTypes = ('int', 'long', 'float')
dateTypes = ('DateTime',)
def __init__(self, env):
self.attrs = {}
# Depending on the result of a tied expression, we will dump, for
# another tag, the series of attrs that this instance represents.
self.tiedExpression = None
# We will need the env to get the full names of attributes to dump.
self.env = env
def computeAttributes(self, expr):
'''p_expr has been evaluated: its result is in expr.result. Depending
on its type, we will dump the corresponding attributes in
self.attrs.'''
exprType = expr.result.__class__.__name__
tags = self.env.tags
attrs = self.attrs
if exprType in self.floatTypes:
attrs[tags['value-type']] = 'float'
attrs[tags['value']] = str(expr.result)
elif exprType in self.dateTypes:
attrs[tags['value-type']] = 'date'
attrs[tags['value']] = expr.result.strftime('%Y-%m-%d')
else:
attrs[tags['value-type']] = 'string'
def evaluate(self, context):
# Evaluate first the tied expression, in order to determine its type.
try:
self.tiedExpression.evaluate(context)
self.tiedExpression.evaluated = True
except Exception, e:
# Don't set "evaluated" to True. This way, when the buffer will
# evaluate the expression directly, we will really evaluate it, so
# the error will be dumped into the pod result.
pass
# Analyse the return type of the expression.
self.computeAttributes(self.tiedExpression)
# Now, self.attrs has been populated. Transform it into a string.
res = ''
for name, value in self.attrs.iteritems():
res += ' %s=%s' % (name, quoteattr(value))
return res
# ------------------------------------------------------------------------------