Add basic merge feature to MasterView

tailbone/templates/master/index.mako

@@ -15,7 +15,34 @@
   ${h.javascript_link(request.static_url('tailbone:static/js/jquery.ui.tailbone.js'))}
   <script type="text/javascript">
     $(function() {
+
         $('.newgrid-wrapper').gridwrapper();
+
+        % if master.mergeable and request.has_perm('{}.merge'.format(permission_prefix)):
+
+            $('form[name="merge-things"] button').button('option', 'disabled', $('.newgrid tbody td.checkbox input:checked').length != 2);
+
+            $('.newgrid-wrapper').on('click', 'tbody td.checkbox input', function() {
+                $('form[name="merge-things"] button').button('option', 'disabled', $('.newgrid tbody td.checkbox input:checked').length != 2);
+            });
+
+
+            $('form[name="merge-things"]').submit(function() {
+                var uuids = [];
+                $('.newgrid tbody td.checkbox input:checked').each(function() {
+                    uuids.push($(this).parents('tr:first').data('uuid'));
+                });
+                if (uuids.length != 2) {
+                    return false;
+                }
+                $(this).find('[name="uuids"]').val(uuids.toString());
+                $(this).find('button')
+                    .button('option', 'label', "Preparing to Merge...")
+                    .button('disable');
+            });
+
+        % endif
+
     });
   </script>
 </%def>
@@ -26,6 +53,13 @@
   % endif
 </%def>
 
-<%def name="grid_tools()"></%def>
+<%def name="grid_tools()">
+  % if master.mergeable and request.has_perm('{}.merge'.format(permission_prefix)):
+    ${h.form(url('{}.merge'.format(route_prefix)), name='merge-things')}
+      ${h.hidden('uuids')}
+      <button type="submit">Merge 2 ${model_title_plural}</button>
+    ${h.end_form()}
+  % endif
+</%def>
 
 ${grid.render_complete(tools=capture(self.grid_tools).strip(), context_menu=capture(self.context_menu_items).strip())|n}

tailbone/templates/master/merge.mako

@@ -0,0 +1,135 @@
+## -*- coding: utf-8 -*-
+<%inherit file="/base.mako" />
+
+<%def name="title()">Merge 2 ${model_title_plural}</%def>
+
+<%def name="head_tags()">
+  ${parent.head_tags()}
+  <script type="text/javascript">
+
+    $(function() {
+
+        $('button.swap').click(function() {
+            $(this).button('disable').button('option', 'label', "Swapping, please wait...");
+            var form = $(this).parents('form');
+            var input = form.find('input[name="uuids"]');
+            var uuids = input.val().split(',');
+            uuids.reverse();
+            input.val(uuids.join(','));
+            form.submit();
+        });
+
+        $('form.merge input[type="submit"]').click(function() {
+            $(this).button('disable').button('option', 'label', "Merging, please wait...");
+            var form = $(this).parents('form');
+            form.append($('<input type="hidden" name="commit-merge" value="yes" />'));
+            form.submit();
+        });
+
+    });
+
+  </script>
+  <style type="text/css">
+    p {
+        margin: 20px auto;
+    }
+    p.warning {
+        color: red;
+    }
+    a.merge-object {
+        font-weight: bold;
+    }
+
+    table {
+        border-collapse: collapse;
+        border-left: 1px solid black;
+        border-top: 1px solid black;
+        font-size: 11pt;
+        margin-left: 50px;
+        min-width: 80%;
+    }
+
+    table th,
+    table td {
+        border-bottom: 1px solid black;
+        border-right: 1px solid black;
+    }
+
+    table td {
+        padding: 5px 10px;
+    }
+
+    table td.value {
+        font-family: monospace;
+        white-space: pre;
+    }
+
+    table.diff tr.diff td.keep-value {
+        background-color: #cfc;
+    }
+    table.diff tr.diff td.remove-value {
+        background-color: #fcc;
+    }
+    table.diff td.result-value.diff {
+        background-color: #fe8;
+    }
+    div.buttons {
+        margin-top: 20px;
+    }
+  </style>
+</%def>
+
+<%def name="context_menu_items()">
+  <li>${h.link_to("Back to {}".format(model_title_plural), url(route_prefix))}</li>
+</%def>
+
+<ul id="context-menu">
+  ${self.context_menu_items()}
+</ul>
+
+<p class="warning">
+  You are about to <strong>merge</strong> two ${model_title} records,
+  (possibly) along with various related data.&nbsp; The tool you are using now
+  is somewhat generic and is not able to give you the full picture of the
+  implications of this merge.&nbsp; You are urged to proceed with caution!
+</p>
+
+<p>
+  The ${h.link_to("{} on the right".format(model_title), view_url(object_to_keep), target='_blank', class_='merge-object')}
+  will be <strong>kept</strong>
+  and the ${h.link_to("{} on the left".format(model_title), view_url(object_to_remove), target='_blank', class_='merge-object')}
+  will be <strong>deleted</strong>.&nbsp; The one which is to be kept may also
+  be updated to reflect certain aspects of the one being deleted; however again
+  the details are up to the app logic for this type of merge and aren't fully
+  known to the generic tool which you're using now.
+</p>
+
+<table class="diff">
+  <thead>
+    <tr>
+      <th>field name</th>
+      <th>deleting ${model_title}</th>
+      <th>keeping ${model_title}</th>
+      <th>resulting ${model_title}</th>
+    </tr>
+  </thead>
+  <tbody>
+    % for field in sorted(merge_fields):
+        <tr${' class="diff"' if keep_data[field] != remove_data[field] else ''|n}>
+          <td class="field">${field}</td>
+          <td class="value remove-value">${repr(remove_data[field])}</td>
+          <td class="value keep-value">${repr(keep_data[field])}</td>
+          <td class="value result-value${' diff' if resulting_data[field] != keep_data[field] else ''}">${repr(resulting_data[field])}</td>
+        </tr>
+    % endfor
+  </tbody>
+</table>
+
+${h.form(request.current_route_url(), class_='merge')}
+<div class="buttons">
+  ${h.hidden('uuids', value='{},{}'.format(object_to_remove.uuid, object_to_keep.uuid))}
+  <a class="button" href="${index_url}">Whoops, nevermind</a>
+  <button type="button" class="swap">Swap which ${model_title} is kept/removed</button>
+  ${h.submit('merge', "Yes, perform this merge")}
+</div>
+${h.end_form()}

tailbone/views/master.py

@@ -55,6 +55,7 @@ class MasterView(View):
     viewable = True
     editable = True
     deletable = True
+    mergeable = False
 
     listing = False
     creating = False
@@ -394,6 +395,70 @@ class MasterView(View):
             'instance_title': instance_title,
             'form': form})
 
+    def get_merge_fields(self):
+        if hasattr(self, 'merge_fields'):
+            return self.merge_fields
+
+    def get_merge_coalesce_fields(self):
+        if hasattr(self, 'merge_coalesce_fields'):
+            return self.merge_coalesce_fields
+        return []
+
+    def merge(self):
+        """
+        Preview and execute a merge of two records.
+        """
+        object_to_remove = object_to_keep = None
+        if self.request.method == 'POST':
+            uuids = self.request.POST.get('uuids', '').split(',')
+            if len(uuids) == 2:
+                object_to_remove = self.Session.query(self.get_model_class()).get(uuids[0])
+                object_to_keep = self.Session.query(self.get_model_class()).get(uuids[1])
+
+                if object_to_remove and object_to_keep and self.request.POST.get('commit-merge') == 'yes':
+                    msg = unicode(object_to_remove)
+                    try:
+                        self.validate_merge(object_to_remove, object_to_keep)
+                    except Exception as error:
+                        self.request.session.flash("Requested merge cannot proceed (maybe swap keep/remove and try again?): {}".format(error), 'error')
+                    else:
+                        self.merge_objects(object_to_remove, object_to_keep)
+                        self.request.session.flash("{} has been merged into {}".format(msg, object_to_keep))
+                        return self.redirect(self.get_action_url('view', object_to_keep))
+
+        if not object_to_remove or not object_to_keep or object_to_remove is object_to_keep:
+            return self.redirect(self.get_index_url())
+
+        remove = self.get_merge_data(object_to_remove)
+        keep = self.get_merge_data(object_to_keep)
+        return self.render_to_response('merge', {'object_to_remove': object_to_remove,
+                                                 'object_to_keep': object_to_keep,
+                                                 'view_url': lambda obj: self.get_action_url('view', obj),
+                                                 'merge_fields': self.get_merge_fields(),
+                                                 'remove_data': remove,
+                                                 'keep_data': keep,
+                                                 'resulting_data': self.get_merge_resulting_data(remove, keep)})
+
+    def validate_merge(self, removing, keeping):
+        """
+        If applicable, your view should override this in order to confirm that
+        the requested merge is valid, in your context.  If it is not - for *any
+        reason* - you should raise an exception; the type does not matter.
+        """
+
+    def get_merge_data(self, obj):
+        raise NotImplementedError("please implement `{}.get_merge_data()`".format(self.__class__.__name__))
+
+    def get_merge_resulting_data(self, remove, keep):
+        result = dict(keep)
+        for field in self.get_merge_coalesce_fields():
+            if remove[field] and not keep[field]:
+                result[field] = remove[field]
+        return result
+
+    def merge_objects(self, removing, keeping):
+        raise NotImplementedError("please implement `{}.merge_objects()`".format(self.__class__.__name__))
+
     ##############################
     # Core Stuff
     ##############################
@@ -635,7 +700,8 @@ class MasterView(View):
             'default_sortkey': getattr(self, 'default_sortkey', None),
             'sortdir': getattr(self, 'sortdir', 'asc'),
             'pageable': self.pageable,
-            'checkboxes': self.checkboxes,
+            'checkboxes': self.checkboxes or (
+                self.mergeable and self.request.has_perm('{}.merge'.format(self.get_permission_prefix()))),
             'checked': self.checked,
             'row_attrs': self.get_row_attrs,
             'cell_attrs': self.get_cell_attrs,
@@ -662,8 +728,12 @@ class MasterView(View):
         defined; it depends on the type of data the grid deals with.
         """
         if callable(self.row_attrs):
-            return self.row_attrs(row, i)
+            attrs = self.row_attrs(row, i)
-        return self.row_attrs
+        else:
+            attrs = dict(self.row_attrs)
+        if self.mergeable:
+            attrs['data-uuid'] = row.uuid
+        return attrs
 
     def get_cell_attrs(self, row, column):
         """
@@ -1142,6 +1212,14 @@ class MasterView(View):
             config.add_tailbone_permission(permission_prefix, '{0}.create'.format(permission_prefix),
                                            "Create new {0}".format(model_title))
 
+        # merge
+        if cls.mergeable:
+            config.add_route('{}.merge'.format(route_prefix), '{}/merge'.format(url_prefix))
+            config.add_view(cls, attr='merge', route_name='{}.merge'.format(route_prefix),
+                            permission='{}.merge'.format(permission_prefix))
+            config.add_tailbone_permission(permission_prefix, '{}.merge'.format(permission_prefix),
+                                           "Merge 2 {}".format(model_title_plural))
+
         # view
         if cls.viewable:
             config.add_tailbone_permission(permission_prefix, '{}.view'.format(permission_prefix),