update docs, code cleanup, changelog

changes/844.added

@@ -0,0 +1 @@
+Added a diff output to the "Generate Intended Config" view and associated REST API.

docs/user/app_feature_intended.md

@@ -45,7 +45,9 @@ curl -s -X GET \
     http://nautobot/api/plugins/golden-config/generate-intended-config/?device_id=231b8765-054d-4abe-bdbf-cd60e049cd8d
 ```
 
-The returned response will contain the rendered configuration for the specified device and the GraphQL data that was used. The web UI provides a simple form to input the device and displays the rendered configuration when submitted.
+The returned response will contain the rendered configuration for the specified device, the GraphQL data that was used, and if applicable, a diff of the most recent intended config that was generated by the **Intended Configuration** job. The web UI provides a simple form to interact with this REST API. You can access the web UI by clicking on "Generate Intended Config" in the "Tools" section of the Golden Config navigation menu.
+
+For more advanced use cases, the REST API and web UI also accept a `graphql_query_id` parameter to specify a custom GraphQL query to use when rendering the configuration. If a `graphql_query_id` is not provided, the default query configured in the Device's Golden Config settings will be used.
 
 ![Intended Configuration Web UI](../images/generate-intended-config-ui.png#only-light)
 ![Intended Configuration Web UI](../images/generate-intended-config-ui-dark.png#only-dark)

nautobot_golden_config/api/views.py

@@ -204,6 +204,26 @@ class GenerateIntendedConfigView(NautobotAPIVersionMixin, GenericAPIView):
     permission_classes = [IsAuthenticated]
     serializer_class = serializers.GenerateIntendedConfigSerializer
 
+    def _get_diff(self, device, intended_config):
+        """Generate a unified diff between the provided config and the intended config stored on the Device's GoldenConfig.intended_config."""
+        diff = None
+        try:
+            golden_config = device.goldenconfig
+            if golden_config.intended_last_success_date is not None:
+                prior_intended_config = golden_config.intended_config
+                diff = "".join(
+                    difflib.unified_diff(
+                        prior_intended_config.splitlines(keepends=True),
+                        intended_config.splitlines(keepends=True),
+                        fromfile="prior intended config",
+                        tofile="rendered config",
+                    )
+                )
+        except models.GoldenConfig.DoesNotExist:
+            pass
+
+        return diff
+
     def _get_object(self, request, model, query_param):
         """Get the requested model instance, restricted to requesting user."""
         pk = request.query_params.get(query_param)
@@ -289,21 +309,7 @@ def get(self, request, *args, **kwargs):
             except Exception as exc:
                 raise GenerateIntendedConfigException(f"Error rendering Jinja template: {exc}") from exc
 
-            diff = None
-            try:
-                golden_config = device.goldenconfig
-                if golden_config.intended_last_success_date is not None:
-                    prior_intended_config = golden_config.intended_config
-                    diff = "".join(
-                        difflib.unified_diff(
-                            prior_intended_config.splitlines(keepends=True),
-                            intended_config.splitlines(keepends=True),
-                            fromfile="prior intended config",
-                            tofile="rendered config",
-                        )
-                    )
-            except Device.goldenconfig.RelatedObjectDoesNotExist:
-                pass
+            diff = self._get_diff(device, intended_config)
 
             return Response(
                 data={

nautobot_golden_config/templates/nautobot_golden_config/generate_intended_config.html

@@ -9,8 +9,14 @@
     .d2h-tag {
         display: none;
     }
-    .d2h-file-collapse {
-        display:none;
+    .d2h-file-name {
+        visibility: hidden;
+    }
+    .d2h-moved {
+        visibility: hidden;
+    }
+    .d2h-file-list-title {
+        display: none;
     }
     .button-container {
         margin-bottom: 24px;
@@ -193,6 +199,9 @@
                     // render the diff
                     if (responseData.diff == null) {
                         diff_render_div.innerHTML = "<p>No intended configuration available to diff against. You may need to run the intended configuration job first.</p>";
+                    // output a message if no diff
+                    } else if (responseData.diff === "") {
+                        diff_render_div.innerHTML = "<p>No changes detected.</p>";
                     } else {
                         diff_render_div.innerHTML = Diff2Html.html(responseData.diff, {
                             drawFileList: true,