Add language code filter on pages query

Author: zerolab

example/example/settings/base.py

@@ -180,6 +180,8 @@
 
 DEFAULT_AUTO_FIELD = "django.db.models.AutoField"
 
+WAGTAIL_I18N_ENABLED = True
+
 try:
     import channels
 

grapple/types/pages.py

@@ -1,4 +1,5 @@
 import graphene
+from django.conf import settings
 from django.contrib.contenttypes.models import ContentType
 from django.dispatch import receiver
 from django.utils.translation import gettext_lazy as _
@@ -223,20 +224,29 @@ def PagesQuery():
     registry.pages[type(WagtailPage)] = Page
 
     class Mixin:
-        pages = QuerySetList(
-            graphene.NonNull(lambda: PageInterface),
-            content_type=graphene.Argument(
+        pages_kwargs = {
+            "content_type": graphene.Argument(
                 graphene.String,
                 description=_("Filter by content type. Uses the `app.Model` notation."),
             ),
-            in_site=graphene.Argument(
+            "in_site": graphene.Argument(
                 graphene.Boolean,
                 description=_("Filter to pages in the current site only."),
                 default_value=False,
             ),
-            enable_search=True,
-            required=True,
-        )
+            "enable_search": True,
+            "required": True,
+        }
+        if getattr(settings, "WAGTAIL_I18N_ENABLED", False):
+            pages_kwargs["language_code"] = graphene.Argument(
+                graphene.String,
+                description=_(
+                    "Filter to pages with the given language code as defined in `WAGTAIL_CONTENT_LANGUAGES`."
+                ),
+            )
+
+        pages = QuerySetList(graphene.NonNull(lambda: PageInterface), **pages_kwargs)
+
         page = graphene.Field(
             PageInterface,
             id=graphene.Int(),
@@ -289,6 +299,10 @@ def resolve_pages(self, info, **kwargs):
                 else:
                     pages = pages.filter(content_type=ctype)
 
+            language_code = kwargs.pop("language_code", "")
+            if language_code and getattr(settings, "WAGTAIL_I18N_ENABLED", False):
+                pages = pages.filter(locale__language_code=language_code)
+
             return resolve_queryset(pages, info, **kwargs)
 
         # Return a specific page, identified by ID or Slug.

grapple/types/structures.py

@@ -25,7 +25,7 @@ class QuerySetList(graphene.List):
     """
     List type with arguments used by Django's query sets.
 
-    This list setts the following arguments on itself:
+    This list sets the following arguments on itself:
 
     * ``id``
     * ``limit``