dzerrenner / easy-select2-m2m Goto Github PK

This is continue of asyncee/django-easy-select2#4 discussion.

First of all, the models.py with improved Parent.__str__ method:

from django.db import models

class Tag(models.Model):
    name = models.CharField(max_length=127)

    def __str__(self):
        return self.name

class Parent(models.Model):
    tags = models.ManyToManyField(to='Tag', null=True, blank=True, symmetrical=False)

    def __str__(self):
        return ",".join([unicode(t) for t in self.tags.all()])

Form validation starts with full_clean method. First of all, it validates every field, then clean() method is called. In your case, the ValidationError happened in _clean_fields method, so clean() was never called.

Changes I made:

1. Set form initial value as a string, instead of list of ids, because Select2 tags expects a string.

2. Extended a full_clean method that cleans tags using raw form data:

   from django.contrib import admin
   from django import forms
   from easy_select2 import Select2TextInput
   from demoapp.models import Tag, Parent
   
   
   class ParentForm(forms.ModelForm):
       def __init__(self, *args, **kwargs):
           super(ParentForm, self).__init__(*args, **kwargs)
   
           def get_choices():
               values = Tag.objects.values_list('name', flat=True).distinct().order_by('name')
               return [x for x in values]
   
           # set select2attrs as stated in https://github.com/asyncee/django-easy-select2/issues/4
           self.fields['tags'].widget = Select2TextInput(
               select2attrs={
                   'tags': get_choices(),
               },
           )
           self.initial = {
               'tags': ', '.join([unicode(t) for t in self.instance.tags.all()]),
           }
   
           # remove the "Use Ctrl for multiple selections" help text
           self.fields['tags'].help_text = ""
   
       def full_clean(self):
           #
           # Tags input should be a list of ids (ints), but for now
           # it is list of single unicode strings, so we should convert
           # it to correct format.
           #
           # Althought this approach is working, it is better to create
           # custom field type that will do appropriate conversions.
           #
           tags_names = self.data.get('tags')
           if tags_names is not None:
               tags_names = tags_names.split(',')
   
               tags_ids = []
               for name in tags_names:
                   try:
                       # It is possible to use get_or_create here.
                       t = Tag.objects.get(name=name)
                   except Tag.DoesNotExist:
                       pass
                   else:
                       tags_ids.append(unicode(t.id))
   
               self.data['tags'] = tags_ids
   
           super(ParentForm, self).full_clean()
   
   
   class ParentAdmin(admin.ModelAdmin):
       form = ParentForm
   
   admin.site.register(Parent, ParentAdmin)
   
   
   admin.site.register(Tag)
   

Hope it helps.