from django.db import models

from django.forms.widgets import Textarea

from wagtail.fields import StreamField

from coderedcms.widgets import ColorPickerWidget

class CoderedStreamField(StreamField):

"""

An exact copy of the Wagtail StreamField, modified to NOT PRESERVE HISTORY

in Django migrations.

Since our StreamFields are generally huge, and we also let sites override

the blocks in our concrete models dynamically, this creates a slew of

migration problems (most commonly: a client overrides CRX_FRONTEND_*,

which changes a string used in a concrete model, which triggers a migration

back in coderedcms). Eliminiating the blocks from the deconstructed

StreamField allows us to have dynamic streamfields without breaking

migrations or having to refactor the core concepts of this package.

Internally, we should ALWAYS use CoderedStreamField on CONCRETE models,

meaning models which are part of our package and saved to the database. For

ABSTRACT models - meaning they are made concrete in the client site - we

should continue to use Wagtail StreamField to keep things Wagtail-ish by

default. The client may then decide to use CoderedStreamField if they are

annoyed by the big migrations.

CAVEAT EMPTOR:

Client sites built with CRX may use this in place of the Wagtail

StreamField, in order to avoid huge migration files. However, note that it

will not be possible to mine data out of a CoderedStreamField during a

migration (e.g. RunPython).

Inspired by:

https://cynthiakiser.com/blog/2022/01/06/trimming-wagtail-migration-cruft.html

"""

def __init__(self, *args, **kwargs):

"""

Patch init to work around django reconstruct not sending empty args.

"""

# If we did not get an arg, pass an empty list through to the parent.

if not args:

args = [[]]

return super().__init__(*args, **kwargs)

def deconstruct(self):

"""

Override to ignore any blocks within the StreamField when

decustructing into a migration.

The output should look something like this, regardless of how many

blocks are nested within the StreamField::

("body", coderedcms.fields.CoderedStreamField([]))

"""

name, path, block_types, kwargs = super().deconstruct()

block_types = []

return name, path, block_types, kwargs

class ColorField(models.CharField):

"""

A CharField which uses the HTML5 color picker widget.

"""

def __init__(self, *args, **kwargs):

kwargs["max_length"] = 255

super().__init__(*args, **kwargs)

def formfield(self, **kwargs):

kwargs["widget"] = ColorPickerWidget

return super().formfield(**kwargs)

class MonospaceField(models.TextField):

"""

A TextField which renders as a large HTML textarea with monospace font.

"""

def formfield(self, **kwargs):

kwargs["widget"] = Textarea(

attrs={

"rows": 12,

"class": "monospace",

"spellcheck": "false",

}

)

return super().formfield(**kwargs)