Add custom encoder support to trigger_client_event()

docs/changelog.rst

@@ -6,6 +6,10 @@ Changelog
 
 * Remove the unnecessary ``type`` attribute on the ``<script>`` tag generated by ``django_htmx_script``.
 
+* Allow custom JSON encoders in ``trigger_client_event()``.
+
+  Thanks to Joey Lange in `PR #349 <https://github.com/adamchainz/django-htmx/pull/349>`__.
+
 1.15.0 (2023-06-13)
 -------------------
 

docs/http.rst

@@ -200,17 +200,22 @@ Response modifying functions
    ``name`` is the name of the event to trigger.
 
    ``params`` specifies optional JSON-compatible parameters for the event.
-   Uses |DjangoJSONEncoder|__ for its extended data type support.
-
-   .. |DjangoJSONEncoder| replace:: ``DjangoJSONEncoder``
-   __ https://docs.djangoproject.com/en/stable/topics/serialization/#django.core.serializers.json.DjangoJSONEncoder
 
    ``after`` selects which of the ``HX-Trigger`` headers to modify:
 
    * ``"receive"``, the default, maps to ``HX-Trigger``
    * ``"settle"`` maps to ``HX-Trigger-After-Settle``
    * ``"swap"`` maps to ``HX-Trigger-After-Swap``
 
+   ``encoder`` specifies the |JSONEncoder|__ class used to generate the JSON.
+   Defaults to |DjangoJSONEncoder|__ for its extended data type support.
+
+   .. |JSONEncoder| replace:: ``JSONEncoder``
+   __ https://docs.python.org/3/library/json.html#json.JSONEncoder
+
+   .. |DjangoJSONEncoder| replace:: ``DjangoJSONEncoder``
+   __ https://docs.djangoproject.com/en/stable/topics/serialization/#django.core.serializers.json.DjangoJSONEncoder
+
    Calling ``trigger_client_event`` multiple times for the same ``response`` and ``after`` will update the appropriate header, preserving existing event specifications.
 
    For example:

src/django_htmx/http.py

@@ -122,6 +122,7 @@ def trigger_client_event(
     params: dict[str, Any] | None = None,
     *,
     after: Literal["receive", "settle", "swap"] = "receive",
+    encoder: type[json.JSONEncoder] = DjangoJSONEncoder,
 ) -> _HttpResponse:
     params = params or {}
 
@@ -146,6 +147,6 @@ def trigger_client_event(
     else:
         data = {name: params}
 
-    response[header] = json.dumps(data, cls=DjangoJSONEncoder)
+    response[header] = json.dumps(data, cls=encoder)
 
     return response

tests/test_http.py

@@ -4,6 +4,7 @@
 from uuid import UUID
 
 import pytest
+from django.core.serializers.json import DjangoJSONEncoder
 from django.http import HttpResponse
 from django.http import StreamingHttpResponse
 from django.test import SimpleTestCase
@@ -235,3 +236,33 @@ def test_django_json_encoder(self):
             response["HX-Trigger"]
             == '{"showMessage": {"uuid": "12345678-1234-5678-1234-567812345678"}}'
         )
+
+    def test_custom_json_encoder(self):
+        class Bean:
+            pass
+
+        class BeanEncoder(DjangoJSONEncoder):
+            def default(self, o):
+                if isinstance(o, Bean):
+                    return "bean"
+
+                return super().default(o)
+
+        response = HttpResponse()
+
+        trigger_client_event(
+            response,
+            "showMessage",
+            {
+                "a": UUID("{12345678-1234-5678-1234-567812345678}"),
+                "b": Bean(),
+            },
+            encoder=BeanEncoder,
+        )
+
+        assert response["HX-Trigger"] == (
+            '{"showMessage": {'
+            + '"a": "12345678-1234-5678-1234-567812345678",'
+            + ' "b": "bean"'
+            + "}}"
+        )