# Gradio Space: JavaScript not executing, fields not populating, persistent SyntaxError in browser console **URL:** \ **Category:** Spaces\ **Created:** [July 19, 2025, 6:33am UTC](https://discuss.huggingface.co/t/gradio-space-javascript-not-executing-fields-not-populating-persistent-syntaxerror-in-browser-console/163689 "2025-07-19T06:33:42Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![nikhmr1235](https://avatars.discourse-cdn.com/v4/letter/n/b2d939/32.png) [@nikhmr1235](https://discuss.huggingface.co/u/nikhmr1235)\ **Post date:** [July 19, 2025, 6:33am UTC](https://discuss.huggingface.co/t/gradio-space-javascript-not-executing-fields-not-populating-persistent-syntaxerror-in-browser-console/163689/1 "2025-07-19T06:33:42Z")
**Subject: Gradio Space: JavaScript not executing, fields not populating, persistent `SyntaxError` in browser console** **Space URL:** `https://huggingface.co/spaces/nikhmr1235/gradio_ui_pr_review_bot` (Please confirm this is your current problematic Space URL) **SDK:** Docker **Problem Description:** My Gradio application’s UI is loading, and the Hugging Face Space status shows “running,” but the JavaScript code intended to pre-fill input fields from URL query parameters is not executing. The input fields (`review_id`, `review_link`) remain empty. **Browser Console Errors (F12):** The browser’s developer console consistently shows the following errors/warnings: 1. `SyntaxError: Unexpected token ';'` (This is the most critical error, preventing JS execution). 2. `Failed to execute 'postMessage' on 'DOMWindow': The target origin provided ('https://huggingface.co') does not match the recipient window's origin ('https://nikhmr1235-gradio-ui-pr-review-bot.hf.space').` (This is a warning, but indicates embedding communication issues). 3. `GET https://nikhmr1235-pr-reviewer-gradio-ui.hf.space/manifest.json 404 (Not Found)` (Less critical, but present). **Steps Taken & Observations:** - **Python Backend Status:** The Hugging Face Space logs confirm the Python `app.py` starts successfully and `demo.launch()` is called, with the Space showing “running” status. No Python-level tracebacks or errors are visible in the server logs. - **JavaScript Debugging:** - Added `console.log` statements within the JavaScript (both in `gr.HTML` and `gr.Blocks(js=...)` parameters). - None of these `DEBUG (JS):` messages appear in the browser console, indicating the JavaScript is not executing at all. - **`demo.launch()` Configuration:** Explicitly set `server_name="0.0.0.0"`, `server_port=7860`, and `share=False`. - **`requirements.txt`:** Minimal, containing only `gradio`, `requests`, `python-dotenv`. - **Gradio Versioning:** Tested with `gradio==4.38.0` and the latest version (by removing the pin). The `SyntaxError` persists with both. - **Rebuilds:** Multiple “Factory rebuilds” have been performed. - **New Space:** Created a brand new Hugging Face Space and deployed the same code; the issue persists. - **Browser:** Tested in Incognito/Private mode (Chrome). **Expected Behavior:** The JavaScript should execute, read the `review_id` and `review_link` query parameters from the URL, and pre-fill the corresponding `gr.Textbox` components in the Gradio UI. **Request:** Please investigate why the JavaScript is failing to execute with a `SyntaxError` in the browser console, preventing the Gradio UI from fully initializing and its embedded JavaScript from running. ---
**Author:** ![John6666](https://sea2.discourse-cdn.com/hellohellohello/user_avatar/discuss.huggingface.co/john6666/32/27664_2.png) [@John6666](https://discuss.huggingface.co/u/John6666)\ **Post date:** [July 19, 2025, 9:25am UTC](https://discuss.huggingface.co/t/gradio-space-javascript-not-executing-fields-not-populating-persistent-syntaxerror-in-browser-console/163689/2 "2025-07-19T09:25:02Z")
Seems unresolved issue…? > > > \### Describe the bug > > \*\*Gradio version 5.23.1\*\* > > I believe this bug is related t…o commit #10608 > > While running Gradio app on \`localhost\` - this security error is observed in Chrome Developer Tools: > > \> const hostname = window.location.hostname; > const origin = hostname.includes(".dev.") > ? \`https://moon-${hostname.split(".")\[1\]}.dev.spaces.huggingface.tech\` > : \`https://huggingface.co\`; > window.parent.postMessage(supports\_zerogpu\_headers, origin); > > Failed to execute 'postMessage' on 'DOMWindow': The target origin provided ('https://huggingface.co') does not match the recipient window's origin ('http://127.0.0.1:7860'). > > The issue is problematic because it causes a security error due to an origin mismatch in the \`postMessage\` call. Specifically, when running a Gradio app on localhost (e.g., http://127.0.0.1:7860), the code incorrectly uses a fixed production origin (https://huggingface.co) as the target for messages. This violates the browser’s same-origin policy. > > \### Have you searched existing issues? 🔎 > > \- \[x\] I have searched and found no existing issues > > \### Reproduction > > Gradio version 5.23.1. Run basic app on localhost. > > > \### Screenshot > > !\[Image\](https://github.com/user-attachments/assets/b95fa97b-7f92-410e-9fda-abbf1528e5e2) > > > \### Logs > > \`\`\`shell > Index.svelte:362 > Failed to execute 'postMessage' on 'DOMWindow': The target origin provided ('https://huggingface.co') does not match the recipient window's origin ('http://127.0.0.1:7860'). > (anonymous) @ Index.svelte:362 > \`\`\` > > \### System Info > > \`\`\`shell > Latest Chrome > \`\`\` > > \### Severity > > Blocking usage of gradio ---
**Author:** ![nikhmr1235](https://avatars.discourse-cdn.com/v4/letter/n/b2d939/32.png) [@nikhmr1235](https://discuss.huggingface.co/u/nikhmr1235)\ **Post date:** [July 19, 2025, 10:03am UTC](https://discuss.huggingface.co/t/gradio-space-javascript-not-executing-fields-not-populating-persistent-syntaxerror-in-browser-console/163689/3 "2025-07-19T10:03:35Z")
> [@John6666](#): > > [Failed to execute 'postMessage' on 'DOMWindow': The target origin provided ('https://huggingface.co') does not match the recipient window's origin · Issue #10893 · gradio-app/gradio · GitHub](https://github.com/gradio-app/gradio/issues/10893) Thanks John! for pointing me to the known issue