Implement ticket merge feature in ticket list. Create intermediate page to choose which data and custom field values to keep on the main ticket.

Also add new template tag filter to use the dictionary get function in template.

helpdesk/forms.py

@@ -8,7 +8,7 @@ forms.py - Definitions of newforms-based forms for creating and maintaining
 """
 import logging
 
-from django.core.exceptions import ObjectDoesNotExist
+from django.core.exceptions import ObjectDoesNotExist, ValidationError
 from django import forms
 from django.conf import settings
 from django.utils.translation import ugettext_lazy as _
@@ -510,3 +510,19 @@ class TicketDependencyForm(forms.ModelForm):
     class Meta:
         model = TicketDependency
         exclude = ('ticket',)
+
+
+class MultipleTicketSelectForm(forms.Form):
+    tickets = forms.ModelMultipleChoiceField(
+        label=_('Tickets to merge'),
+        queryset=Ticket.objects.all(),
+        widget=forms.SelectMultiple(attrs={'class': 'form-control'})
+    )
+
+    def clean_tickets(self):
+        tickets = self.cleaned_data.get('tickets')
+        if len(tickets) < 2:
+            raise ValidationError(_('Please choose at least 2 tickets'))
+        if len(tickets) > 4:
+            raise ValidationError(_('Impossible to merge more than 4 tickets...'))
+        return tickets