Include whole context to pass csrf_token to form.html & set category on widget

src/newsreader/news/collection/templates/news/collection/views/import.html

@@ -5,6 +5,6 @@
 {% block content %}
   <main id="import--page" class="main">
     {% url "news:collection:rules" as cancel_url %}
-    {% include "form.html" with form=form title="Import an OPML file" cancel_url=cancel_url only %}
+    {% include "form.html" with form=form title="Import an OPML file" cancel_url=cancel_url %}
   </main>
 {% endblock %}

src/newsreader/news/collection/templates/news/collection/views/rule-create.html

@@ -5,6 +5,6 @@
 {% block content %}
   <main id="rule--page" class="main">
     {% url "news:collection:rules" as cancel_url %}
-    {% include "form/form.html" with form=form title="Create rule" cancel_url=cancel_url only %}
+    {% include "form/form.html" with form=form title="Create rule" cancel_url=cancel_url %}
   </main>
 {% endblock %}

src/newsreader/news/collection/templates/news/collection/views/rule-update.html

@@ -5,6 +5,6 @@
 {% block content %}
   <main id="rule--page" class="main">
     {% url "news:collection:rules" as cancel_url %}
-    {% include "form/form.html" with form=form title="Update rule" cancel_url=cancel_url only %}
+    {% include "form/form.html" with form=form title="Update rule" cancel_url=cancel_url %}
   </main>
 {% endblock %}

src/newsreader/news/core/forms.py

@@ -7,7 +7,7 @@ from newsreader.news.core.widgets import RulesWidget
 
 class CategoryForm(forms.ModelForm):
     rules = forms.ModelMultipleChoiceField(
-        required=False, queryset=CollectionRule.objects.all(), widget=RulesWidget
+        required=False, queryset=CollectionRule.objects.none(), widget=RulesWidget
     )
 
     def __init__(self, *args, **kwargs):
@@ -17,6 +17,8 @@ class CategoryForm(forms.ModelForm):
 
         self.fields["rules"].queryset = CollectionRule.objects.filter(user=self.user)
 
+        self.fields["rules"].widget.category = self.instance
+
     def save(self, commit=True):
         instance = super().save(commit=False)
         instance.user = self.user

src/newsreader/news/core/templates/news/core/views/category-create.html

@@ -5,6 +5,6 @@
 {% block content %}
   <main id="category--page" class="main">
     {% url "news:core:categories" as cancel_url %}
-    {% include "form/form.html" with form=form title="Create category" cancel_url=cancel_url only %}
+    {% include "form/form.html" with form=form title="Create category" cancel_url=cancel_url %}
   </main>
 {% endblock %}

src/newsreader/news/core/templates/news/core/views/category-update.html

@@ -1,9 +1,10 @@
-{% extends "news/core/views/category.html" %}
+{% extends "base.html" %}
 
-{% block form-header %}
-  <h1 class="h1 form__title">Update category</h1>
-{% endblock %}
+{% load static %}
 
-{% block confirm-button %}
-  <button class="button button--confirm">Save category</button>
+{% block content %}
+  <main id="category--page" class="main">
+    {% url "news:core:categories" as cancel_url %}
+    {% include "form/form.html" with form=form title="Update category" cancel_url=cancel_url %}
+  </main>
 {% endblock %}

src/newsreader/news/core/widgets.py

@@ -8,4 +8,7 @@ class RulesWidget(CheckboxSelectMultiple):
     def create_option(self, *args, **kwargs):
         option = super().create_option(*args, **kwargs)
         instance = self.choices.queryset.get(pk=option["value"])
+
+        if self.category and instance.category:
+            option["selected"] = self.category.pk == instance.category.pk
         return {**option, "instance": instance}