Static Alias Placeholder functionality (django CMS Static Placeholder…

… replacement) (#59)

* Add a new identifier field

* Created a tag and a start to a suite of tests for the feature

* Updated the implementation to create a default category and create an alias if one doesn't yet exist for the static code

* Added versioning integration with a default user

* Added a template and versioning tests, highlights some weaknesses in the previous configuration

* Added the latest version of the model migration

djangocms_alias/admin.py

@@ -42,6 +42,7 @@ def save_model(self, request, obj, form, change):
 class AliasAdmin(admin.ModelAdmin):
     list_display = ['name', 'category']
     fields = ('category',)
+    readonly_fields = ('static_code', 'site')
 
     def get_urls(self):
         return urlpatterns + super().get_urls()

djangocms_alias/cms_menus.py

@@ -10,8 +10,8 @@ class AliasDisableMenu(Modifier):
 
     def modify(self, request, nodes, namespace, root_id, post_cut, breadcrumb):
         if (
-            request.toolbar.app_name == PLUGIN_URL_NAME_PREFIX or
-            isinstance(request.toolbar.obj, AliasContent)
+            request.toolbar.app_name == PLUGIN_URL_NAME_PREFIX
+            or isinstance(request.toolbar.obj, AliasContent)
         ):
             return []
         return nodes

djangocms_alias/constants.py

@@ -8,3 +8,5 @@
 SET_ALIAS_POSITION_URL_NAME = '{}_set_alias_position'.format(PLUGIN_URL_NAME_PREFIX)  # noqa: E501
 SELECT2_ALIAS_URL_NAME = '{}_select2'.format(PLUGIN_URL_NAME_PREFIX)
 USAGE_ALIAS_URL_NAME = '{}_alias_usage'.format(PLUGIN_URL_NAME_PREFIX)
+
+DEFAULT_STATIC_ALIAS_CATEGORY_NAME = "Static Alias"

djangocms_alias/forms.py

@@ -164,7 +164,11 @@ def save(self):
 
 
 class CreateAliasWizardForm(forms.Form):
-    name = forms.CharField(required=True, widget=AdminTextInputWidget())
+    name = forms.CharField(
+        label=_('Name'),
+        required=True,
+        widget=AdminTextInputWidget()
+    )
     category = forms.ModelChoiceField(
         queryset=Category.objects.all(),
         required=True,

djangocms_alias/migrations/0002_auto_20200723_1424.py

@@ -0,0 +1,40 @@
+# Generated by Django 2.2.13 on 2020-07-23 14:24
+
+from django.db import migrations, models
+import django.db.models.deletion
+import parler.fields
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('sites', '0002_alter_domain_unique'),
+        ('djangocms_alias', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='alias',
+            name='creation_method',
+            field=models.CharField(blank=True, choices=[('template', 'by template'), ('code', 'by code')], default='code', max_length=20, verbose_name='creation_method'),
+        ),
+        migrations.AddField(
+            model_name='alias',
+            name='site',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, to='sites.Site'),
+        ),
+        migrations.AddField(
+            model_name='alias',
+            name='static_code',
+            field=models.CharField(blank=True, help_text='To render the alias in templates.', max_length=255, null=True, verbose_name='static code'),
+        ),
+        migrations.AlterField(
+            model_name='categorytranslation',
+            name='master',
+            field=parler.fields.TranslationsForeignKey(editable=False, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='translations', to='djangocms_alias.Category'),
+        ),
+        migrations.AlterUniqueTogether(
+            name='alias',
+            unique_together={('static_code', 'site')},
+        ),
+    ]

djangocms_alias/models.py

@@ -2,6 +2,7 @@
 from collections import defaultdict
 
 from django.conf import settings
+from django.contrib.sites.models import Site
 from django.db import models, transaction
 from django.db.models import F, Q
 from django.utils.encoding import force_text
@@ -68,6 +69,16 @@ def get_absolute_url(self):
 
 
 class Alias(models.Model):
+    CREATION_BY_TEMPLATE = 'template'
+    CREATION_BY_CODE = 'code'
+    CREATION_METHODS = (
+        (CREATION_BY_TEMPLATE, _('by template')),
+        (CREATION_BY_CODE, _('by code')),
+    )
+    creation_method = models.CharField(
+        verbose_name=_('creation_method'), choices=CREATION_METHODS,
+        default=CREATION_BY_CODE, max_length=20, blank=True,
+    )
     category = models.ForeignKey(
         Category,
         verbose_name=_('category'),
@@ -78,11 +89,20 @@ class Alias(models.Model):
         verbose_name=_('position'),
         default=0,
     )
+    static_code = models.CharField(
+        verbose_name=_('static code'),
+        max_length=255,
+        blank=True,
+        null=True,
+        help_text=_('To render the alias in templates.')
+    )
+    site = models.ForeignKey(Site, on_delete=models.CASCADE, null=True, blank=True)
 
     class Meta:
         verbose_name = _('alias')
         verbose_name_plural = _('aliases')
         ordering = ['position']
+        unique_together = (('static_code', 'site'),)  # Only restrict instances that have a site specified
 
     def __init__(self, *args, **kwargs):
         self._plugins_cache = {}
@@ -161,8 +181,13 @@ def get_content(self, language=None, show_draft_content=False):
             ).filter(language=language)
 
             if show_draft_content and is_versioning_enabled():
+                from djangocms_versioning.constants import DRAFT, PUBLISHED
                 from djangocms_versioning.helpers import remove_published_where
+
+                # Ensure that we are getting the latest valid content, the top most version can become
+                # archived with a previous version re-published
                 qs = remove_published_where(qs)
+                qs = qs.filter(Q(versions__state=DRAFT) | Q(versions__state=PUBLISHED)).order_by('-versions__created')
 
             self._content_cache[language] = qs.first()
             return self._content_cache[language]

djangocms_alias/templatetags/djangocms_alias_tags.py

@@ -2,10 +2,22 @@
 
 from django import template
 
+from cms.templatetags.cms_tags import PlaceholderOptions
 from cms.toolbar.utils import get_toolbar_from_request
+from cms.utils import get_current_site, get_language_from_request
+from cms.utils.i18n import get_default_language_for_site
+from cms.utils.placeholder import validate_placeholder_name
 from cms.utils.urlutils import add_url_parameters, admin_reverse
 
-from ..constants import USAGE_ALIAS_URL_NAME
+from classytags.arguments import Argument, MultiValueArgument
+from classytags.core import Tag
+
+from ..constants import (
+    DEFAULT_STATIC_ALIAS_CATEGORY_NAME,
+    USAGE_ALIAS_URL_NAME,
+)
+from ..models import Alias, AliasContent, Category
+from ..utils import is_versioning_enabled
 
 
 register = template.Library()
@@ -40,3 +52,109 @@ def render_alias(context, instance, editable=False):
         )
         return content or ''
     return ''
+
+
+@register.tag
+class StaticAlias(Tag):
+    """
+    This template node is used to render Alias contents and is designed to be a
+    replacement for the CMS Static Placeholder.
+
+    eg: {% static_alias "identifier_text" %}
+    eg: {% static_alias "identifier_text" site %}
+
+    Keyword arguments:
+    static_code -- the unique identifier of the Alias
+    site -- If site is supplied an Alias instance will be created per site.
+    """
+    name = 'static_alias'
+    options = PlaceholderOptions(
+        Argument('static_code', resolve=False),
+        MultiValueArgument('extra_bits', required=False, resolve=False),
+        blocks=[
+            ('endstatic_alias', 'nodelist'),
+        ],
+    )
+
+    def _get_alias(self, request, static_code, extra_bits):
+        alias_filter_kwargs = {
+            'static_code': static_code,
+        }
+        # Site
+        current_site = get_current_site()
+        if 'site' in extra_bits:
+            alias_filter_kwargs['site'] = current_site
+        else:
+            alias_filter_kwargs['site_id__isnull'] = True
+
+        # Try and find an Alias to render
+        alias = Alias.objects.filter(**alias_filter_kwargs).first()
+        # If there is no alias found we need to create one
+        if not alias:
+
+            # If versioning is enabled we can only create the records with a logged in user / staff member
+            if is_versioning_enabled() and not request.user.is_authenticated:
+                return None
+
+            language = get_default_language_for_site(current_site)
+            # Parlers get_or_create doesn't work well with translations, so we must perform our own get or create
+            default_category = Category.objects.filter(translations__name=DEFAULT_STATIC_ALIAS_CATEGORY_NAME).first()
+            if not default_category:
+                default_category = Category.objects.create(name=DEFAULT_STATIC_ALIAS_CATEGORY_NAME)
+
+            alias_creation_kwargs = {
+                'static_code': static_code,
+                'creation_method': Alias.CREATION_BY_TEMPLATE
+            }
+            # Site
+            if 'site' in extra_bits:
+                alias_creation_kwargs['site'] = current_site
+
+            alias = Alias.objects.create(category=default_category, **alias_creation_kwargs)
+            alias_content = AliasContent.objects.create(
+                alias=alias,
+                name=static_code,
+                language=language,
+            )
+
+            if is_versioning_enabled():
+                from djangocms_versioning.models import Version
+
+                Version.objects.create(content=alias_content, created_by=request.user)
+
+        return alias
+
+    def render_tag(self, context, static_code, extra_bits, nodelist=None):
+        request = context.get('request')
+
+        if not static_code or not request:
+            # an empty string was passed in or the variable is not available in the context
+            if nodelist:
+                return nodelist.render(context)
+            return ''
+
+        validate_placeholder_name(static_code)
+
+        toolbar = get_toolbar_from_request(request)
+        renderer = toolbar.get_content_renderer()
+        alias = self._get_alias(request, static_code, extra_bits)
+
+        if not alias:
+            return ''
+
+        # Get draft contents in edit or preview mode?
+        get_draft_content = False
+        if toolbar.edit_mode_active or toolbar.preview_mode_active:
+            get_draft_content = True
+
+        language = get_language_from_request(request)
+        placeholder = alias.get_placeholder(language=language, show_draft_content=get_draft_content)
+
+        if placeholder:
+            content = renderer.render_placeholder(
+                placeholder=placeholder,
+                context=context,
+                nodelist=nodelist,
+            )
+            return content
+        return ''

djangocms_alias/views.py

@@ -233,8 +233,8 @@ def render_replace_response(request, new_plugins, source_placeholder=None,
 @transaction.atomic
 def set_alias_position_view(request):
     if (
-        not request.user.is_staff or
-        not request.user.has_perm('djangocms_alias.change_alias')
+        not request.user.is_staff
+        or not request.user.has_perm('djangocms_alias.change_alias')
     ):
         raise PermissionDenied
 

test_settings.py

@@ -63,6 +63,11 @@
     'TEMPLATE_DIRS': [
         os.path.join('tests', 'templates'),
     ],
+    'CMS_TEMPLATES': (
+        ("fullwidth.html", "Fullwidth"),
+        ("page.html", "Normal page"),
+        ('static_alias.html', 'Static Alias Template'),
+    ),
     'PARLER_LANGUAGES': {
         1: [
             {

tests/base.py

@@ -71,7 +71,8 @@ def _get_draft_page_placeholder(self):
         page_content = create_title(self.language, 'Draft Page', self.page, created_by=self.superuser)
         return page_content.get_placeholders().get(slot='content')
 
-    def _create_alias(self, plugins=None, name='test alias', category=None, position=0, language=None, published=True):
+    def _create_alias(self, plugins=None, name='test alias', category=None, position=0,
+                      language=None, published=True, static_code="", site=None):
         if language is None:
             language = self.language
         if category is None:
@@ -81,6 +82,8 @@ def _create_alias(self, plugins=None, name='test alias', category=None, position
         alias = AliasModel.objects.create(
             category=category,
             position=position,
+            static_code=static_code,
+            site=site,
         )
         alias_content = AliasContent.objects.create(
             alias=alias,

tests/templates/static_alias.html

@@ -0,0 +1,13 @@
+{% extends "base.html" %}
+{% load cms_tags djangocms_alias_tags %}
+
+{% block title %}{% page_attribute 'title' %}{% endblock title %}
+
+{% block content %}
+    <h2>Static Alias tags</h2>
+
+
+    {% static_alias "template_example_global_alias_code" %}
+{% endblock content %}
+
+