Allow users to change version slug

readthedocs/builds/forms.py

@@ -22,19 +22,25 @@
     Version,
     VersionAutomationRule,
 )
+from readthedocs.builds.version_slug import generate_version_slug
 
 
 class VersionForm(forms.ModelForm):
+    project = forms.CharField(widget=forms.HiddenInput(), required=False)
+
     class Meta:
         model = Version
         states_fields = ["active", "hidden"]
         privacy_fields = ["privacy_level"]
         fields = (
+            "project",
+            "slug",
             *states_fields,
             *privacy_fields,
         )
 
     def __init__(self, *args, **kwargs):
+        self.project = kwargs.pop("project")
         super().__init__(*args, **kwargs)
 
         field_sets = [
@@ -66,11 +72,17 @@ def __init__(self, *args, **kwargs):
             )
         )
 
+        # Don't allow changing the slug of machine created versions
+        # (stable/latest), as we rely on the slug to identify them.
+        if self.instance and self.instance.machine:
+            self.fields["slug"].disabled = True
+
         self.helper = FormHelper()
         self.helper.layout = Layout(*field_sets)
         # We need to know if the version was active before the update.
         # We use this value in the save method.
         self._was_active = self.instance.active if self.instance else False
+        self._previous_slug = self.instance.slug if self.instance else None
 
     def clean_active(self):
         active = self.cleaned_data["active"]
@@ -88,7 +100,43 @@ def _is_default_version(self):
         project = self.instance.project
         return project.default_version == self.instance.slug
 
+    def clean_slug(self):
+        slug = self.cleaned_data["slug"]
+        validated_slug = generate_version_slug(slug)
+        if slug != validated_slug:
+            msg = _(
+                "The slug can contain lowercase letters, numbers, dots, dashes or underscores, "
+                f"and it must start with a lowercase letter or a number. Consider using '{validated_slug}'."
+            )
+            raise forms.ValidationError(msg)
+
+        # NOTE: Django already checks for unique slugs and raises a ValidationError,
+        # but that message is attached to the whole form instead of the the slug field.
+        # So we do the check here to provide a better error message.
+        if (
+            self.project.versions.filter(slug=slug)
+            .exclude(pk=self.instance.pk)
+            .exists()
+        ):
+            raise forms.ValidationError(_("A version with that slug already exists."))
+        return slug
+
+    def clean_project(self):
+        return self.project
+
     def save(self, commit=True):
+        # If the slug was changed, and the version was active,
+        # we need to delete all the resources, since the old slug is used in several places.
+        # NOTE: we call clean_resources over the instance with the previous slug,
+        # as all resources are associated with that slug.
+        if "slug" in self.changed_data and self._was_active:
+            self.instance.slug = self._previous_slug
+            self.instance.clean_resources()
+            self.instance.slug = self.cleaned_data["slug"]
+            # We need to set the flag to False,
+            # so the post_save method triggers a new build.
+            self._was_active = False
+
         obj = super().save(commit=commit)
         obj.post_save(was_active=self._was_active)
         return obj

readthedocs/builds/models.py

@@ -421,6 +421,7 @@ def clean_resources(self):
         clean_project_resources(project=self.project, version=self)
         self.built = False
         self.save()
+        self.purge_cdn()
 
     def save(self, *args, **kwargs):
         if not self.slug:
@@ -447,10 +448,15 @@ def post_save(self, was_active=False):
         # If the version is deactivated, we need to clean up the files.
         if was_active and not self.active:
             self.clean_resources()
+            return
         # If the version is activated, we need to trigger a build.
         if not was_active and self.active:
             trigger_build(project=self.project, version=self)
-        # Purge the cache from the CDN.
+        # Purge the cache from the CDN for any other changes.
+        self.purge_cdn()
+
+    def purge_cdn(self):
+        """Purge the cache from the CDN."""
         version_changed.send(sender=self.__class__, version=self)
 
     @property

readthedocs/projects/views/private.py

@@ -275,11 +275,6 @@ def get_queryset(self):
             only_active=False,
         )
 
-    def get_form(self, data=None, files=None, **kwargs):
-        # This overrides the method from `ProjectAdminMixin`,
-        # since we don't have a project.
-        return self.get_form_class()(data, files, **kwargs)
-
     def form_valid(self, form):
         form.save()
         return HttpResponseRedirect(self.get_success_url())