Fix refresh wiping all links when JSON file is missing

When the file at json_path didn't exist, clicking Refresh Outputs
returned empty keys causing all outputs and links to be removed.
Now the API returns an error flag and the frontend bails out early,
preserving existing outputs.

Bump version to 1.2.1.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

json_loader_dynamic.py

@@ -63,6 +63,8 @@ if PromptServer is not None:
             seq = 1
         data = read_json_data(json_path)
         target = get_batch_item(data, seq)
+        if not data:
+            return web.json_response({"keys": [], "types": [], "error": "file_not_found"})
         keys = []
         types = []
         if isinstance(target, dict):

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "comfyui-json-dynamic"
-version = "1.2.0"
+version = "1.2.1"
 description = "ComfyUI nodes for dynamic JSON loading and string/path utility operations"
 license = { file = "LICENSE" }
 requires-python = ">=3.10"

web/json_dynamic.js

@@ -39,7 +39,14 @@ app.registerExtension({
                 const resp = await api.fetchApi(
                     `/json_dynamic/get_keys?path=${encodeURIComponent(pathWidget.value)}&sequence_number=${seqWidget?.value || 1}`
                 );
-                const { keys, types } = await resp.json();
+                const data = await resp.json();
+                const { keys, types } = data;
+
+                // If the file wasn't found, keep existing outputs and links intact
+                if (data.error === "file_not_found") {
+                    console.warn("[JSONDynamicLoader] File not found, keeping existing outputs:", pathWidget.value);
+                    return;
+                }
 
                 // Store keys and types in hidden widgets for persistence
                 const okWidget = this.widgets?.find(w => w.name === "output_keys");