feat(easel): add widget mode support

gallery/easel/route/view/common/utils/template.py

@@ -1,6 +1,7 @@
 from pathlib import Path
 
 from babel.dates import format_date
+from fastapi import Request
 from fastapi.templating import Jinja2Templates
 
 from gallery.version import __version__
@@ -8,11 +9,23 @@ from gallery.version import __version__
 from ...translation import _
 
 
+def is_widget(request: Request) -> bool:
+    return (request.url.hostname and request.url.hostname.startswith("weather")) or (
+        request.query_params.get("widget") is not None
+    )
+
+
+def context_processor(request: Request) -> dict:
+    return {
+        "is_widget": is_widget(request),
+    }
+
+
 def build_templates(templates_dir: Path | None = None, filters: dict | None = None) -> Jinja2Templates:
     directory = [Path(__file__).parent.parent / "templates"]
     if templates_dir:
         directory.append(templates_dir)
-    templates = Jinja2Templates(directory=directory)
+    templates = Jinja2Templates(directory=directory, context_processors=[context_processor])
     templates.env.globals.update(
         {
             "_": _,