Question

the situation

In my example I want to create a Page model with a many to many relationship with a content-blocks model.

1. A page has a title, slug, and main content block.
2. content blocks have a title and a content block.

What I can get:

Showing page.blocks in the admin form displays a multi select of content blocks

Creating an inline form for the content blocks on the page admin shows several selects with a + sign to add more

What I am trying to accomplish:

Full CRUD on content block on the page admin

Note: Due to the difficulty of my request, I’m beginning to believe the UX pattern im trying to accomplish is wrong. If I want a content creator to come in and create a page, pick some existing content blocks (ex: an existing sidebar content block), and then create a new custom block. I don’t think i want him to have to jump all over the place to do this…

Related Question without solutions:
How do I use a TabularInline with editable fields on a ManyToMany relationship?

EDIT

my admin.py

from django.contrib import admin
from django.contrib.flatpages.admin import FlatpageForm, FlatPageAdmin
from django.contrib.flatpages.models import FlatPage
from my_flatpages.models import ExtendedFlatPage, ContentBlock
from mptt.admin import MPTTModelAdmin
from django import forms
import settings

"""
Extended Flatpage Form
"""
class ExtendedFlatPageForm(FlatpageForm):
    class Meta:
        model = ExtendedFlatPage


"""
Page Content Block inline form
"""
class ContentBlockInlineAdminForm(forms.ModelForm):
    # Add form field for selecting an existing content block
    content_block_choices = [('', 'New...')]
    content_block_choices.extend([(c.id, c) for c in ContentBlock.objects.all()])
    content_blocks = forms.ChoiceField(choices=content_block_choices, label='Content Block')

    def __init(self, *args, **kwargs):
        super(ContentBlockInlineAdminForm, self).__init__(*args, **kwargs)

        # Show as existing content block if it already exists
        if self.instance.pk:
            self.fields['content_block'].initial = self.instance.pk
            self.fields['title'].initial = ''
            self.fields['content'].initial = ''

        # Make title and content not required so user can opt to select existing content block
        self.fields['title'].required = False
        self.fields['content'].required = False

    def clean(self):
        content_block = self.cleaned_data.get('content_block')
        title = self.cleaned_data.get('title')
        content = self.cleaned_data.get('content')

        # Validate that either user has selected existing content block or entered info for new content block
        if not content_block and not title and not content:
            raise forms.ValidationError('You must either select an existing content block or enter the title and content for a new content block')


"""
Content Block Inline Admin
"""
class ContentBlockInlineAdmin(admin.TabularInline):
    form = ContentBlockInlineAdminForm

    class Meta:
        model = ContentBlock
        extra = 1


"""
Extended Flatpage Admin
"""
class ExtendedFlatPageAdmin(FlatPageAdmin, MPTTModelAdmin):
    form = ExtendedFlatPageForm
    fieldsets = (
        (
            None, 
            {
                'fields': ('url', 'title', 'content', ('parent', 'sites'))
            }
        ),
        (
            'SEO Fields', 
            {
                'fields': ('seo_title', 'seo_keywords', 'seo_description'), 
            'classes': ('collapse', )
            }
        ),
        (
            'Advanced options', 
            {
                'fields': ('enable_comments', 'registration_required', 'template_name'), 
            'classes': ('collapse', )
            }
        ),
    )
    inlines = (ContentBlockInlineAdmin,)


    class Media:
        js = (
            'https://ajax.googleapis.com/ajax/libs/jquery/1.5.2/jquery.min.js',
            settings.MEDIA_URL + 'js/tinymce/jquery.tinymce.js',
            settings.MEDIA_URL + 'js/init_tinymce.js'
        )

admin.site.unregister(FlatPage)
admin.site.register(ExtendedFlatPage, ExtendedFlatPageAdmin)

Answer 1

This isn’t the answer I was looking for, BUT, What I ended up going with is

class Page(models.Model):
    ....

class ContentBlock(models.Model):
    page = models.ForeignKey(
        Page, 
        blank = True,
        null = True,
    )
    ....

and then having a regular tabular inline for ContentBlock on the page admin form.

So that way I can have page specific content blocks related to a page, AND be able to have generic content blocks able to be used wherever.

Then, I created an inclusion tag to render a content block by name that I use in my templates.