Refactor document indexing app

Convert half the widget to HTML widgets.

Rename links and views to use the nomeclature _template_
and _instance_ to differenciate between index instances
and index templates.

Update URL parameters to use the "_id" form.

Add more tests.

Add model permission inheritance to the IndexTemplateNode,
and IndexInstanceNode models.

Remove the level and document count display from the
instance node. Display instead the total items.

Use a FilteredSelectionForm subclass to display the list
of index templates to rebuild.

Add missing icons.

Add keyword arguments to links.

Modernize tests to use the document test mixin.

Update the permission requirements for the index template
document type selection screen. The document type view
permission is now required in addition to the index
template edit permission.

Use ExternalObjectMixin to reduce the code in all views.

Signed-off-by: Roberto Rosario <Roberto.Rosario@mayan-edms.com>

mayan/apps/document_indexing/forms.py

@@ -4,30 +4,23 @@ from django import forms
 from django.utils.encoding import force_text
 from django.utils.translation import ugettext_lazy as _
 
-from mayan.apps.acls.models import AccessControlList
 from mayan.apps.common.classes import ModelProperty
+from mayan.apps.common.forms import FilteredSelectionForm
 from mayan.apps.documents.models import Document
 
 from .models import Index, IndexTemplateNode
 from .permissions import permission_document_indexing_rebuild
 
 
-class IndexListForm(forms.Form):
-    indexes = forms.ModelMultipleChoiceField(
-        help_text=_('Indexes to be queued for rebuilding.'),
-        label=_('Indexes'), queryset=Index.objects.none(),
-        required=False, widget=forms.widgets.CheckboxSelectMultiple()
-    )
-
-    def __init__(self, *args, **kwargs):
-        user = kwargs.pop('user')
-        super(IndexListForm, self).__init__(*args, **kwargs)
-        queryset = AccessControlList.objects.restrict_queryset(
-            permission=permission_document_indexing_rebuild,
-            queryset=Index.objects.filter(enabled=True),
-            user=user
-        )
-        self.fields['indexes'].queryset = queryset
+class IndexTemplateFilteredForm(FilteredSelectionForm):
+    class Meta:
+        allow_multiple = True
+        field_name = 'index_templates'
+        help_text = _('Index templates to be queued for rebuilding.')
+        label = _('Index templates')
+        queryset = Index.objects.filter(enabled=True)
+        permission = permission_document_indexing_rebuild
+        widget_attributes = {'class': 'select2'}
 
 
 class IndexTemplateNodeForm(forms.ModelForm):