Source code for feincms3.plugins.snippet

"""
Plugin for including template snippets through the CMS
"""

from collections import defaultdict

from content_editor.admin import ContentEditorInline
from django.db import models
from django.db.models import signals
from django.template.base import Template
from django.template.loader import render_to_string
from django.utils.translation import gettext_lazy as _

from feincms3.mixins import ChoicesCharField
from feincms3.renderer import render_in_context


__all__ = ("Snippet", "SnippetInline", "render_snippet")




def render_snippet(plugin, context=None, **kwargs):
    """
    Renders the selected template using ``render_to_string``
    """
    return render_to_string(plugin.template_name, {"plugin": plugin})





class Snippet(models.Model):
    """
    Template snippet plugin
    """

    template_name = ChoicesCharField(_("template"), max_length=100)

    class Meta:
        abstract = True
        verbose_name = _("predefined snippet")
        verbose_name_plural = _("predefined snippets")

    def __str__(self):
        return self.get_template_name_display()



    @staticmethod
    def fill_template_name_choices(sender, **kwargs):
        """
        Fills in the choices for ``template_name`` from the ``TEMPLATES`` class
        variable. This method is a receiver of Django's ``class_prepared``
        signal.
        """
        if issubclass(sender, Snippet) and not sender._meta.abstract:
            sender._meta.get_field("template_name").choices = [
                choice[:2] for choice in sender.TEMPLATES
            ]




    @classmethod
    def register_with(cls, renderer, **kwargs):
        """
        This helper registers the snippet plugin with a
        ``TemplatePluginRenderer`` while adding support for template-specific
        context functions. The templates specified using the ``TEMPLATES``
        class variable may contain a callable which receives the plugin
        instance and the template context and returns a context dictionary.
        """
        from feincms3.renderer import default_context

        templates = defaultdict(
            lambda: Template(""),
            ((row[0], row[0]) for row in cls.TEMPLATES),
        )
        context_fns = defaultdict(
            lambda: default_context,
            [(row[0], row[2]) for row in cls.TEMPLATES if len(row) > 2],
        )

        def _render_snippet(plugin, context):
            return render_in_context(
                context,
                templates[plugin.template_name],
                context_fns[plugin.template_name](plugin, context),
            )

        renderer.register(cls, _render_snippet, **kwargs)




signals.class_prepared.connect(Snippet.fill_template_name_choices)




class SnippetInline(ContentEditorInline):
    """
    Snippet inline does nothing special, it simply exists for consistency
    with the other feincms3 plugins
    """

    button = '<span class="material-icons">smart_toy</span>'