# Custom JavaScript not shown when moving to new task

**URL:** <https://support.prodi.gy/t/custom-javascript-not-shown-when-moving-to-new-task/7637>\
**Category:** Uncategorized\
**Created:** [December 17, 2025, 9:04am UTC](https://support.prodi.gy/t/custom-javascript-not-shown-when-moving-to-new-task/7637 "2025-12-17T09:04:17Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![helmiina](https://avatars.discourse-cdn.com/v4/letter/h/ee7513/32.png) [@helmiina](https://support.prodi.gy/u/helmiina)\
**Post date:** [December 17, 2025, 9:04am UTC](https://support.prodi.gy/t/custom-javascript-not-shown-when-moving-to-new-task/7637/1 "2025-12-17T09:04:17Z")

</div>

Hi there,

I want to show some additional information, retrieved from the data of the current task, in our task interface using JavaScript.

I have the following code working nicely for showing information from `window.prodigy.content` when the user accesses the first task on their browser:

```python
(async () => {
    while (typeof window.prodigy.content == "undefined") {
        console.log("content not loaded yet")
        await new Promise(resolve => setTimeout(resolve, 1000));
    }
    console.log("content loaded")
    const acceptValues = window.prodigy.content.combined_accept
    const options = window.prodigy.content.options

    const reasonsObj = options.filter(el => acceptValues.includes(el.id))
    const reasons = reasonsObj.map(el => el.text.toLowerCase()).join(", ")
    console.log("reasons: " + reasons)
    
    window.prodigy.update({ reason: "This task was rejected in review for reason(s): " + reasons })
})();

```

However, when the user answers and submits the first task, the next task does not render the JavaScript. I can see from the console that the needed information is present in `window.prodigy.content` but I assume the JS is never reloaded when changing tasks.

How could I change this so that the JS is shown in every task? I'm using version `prodigy 1.18.0`.

PS. I had to resort to the async above to show the custom information _after_ `window.prodigy.content` is available, all the existing functions `prodigyload`, `prodigymount` etc. seemed to fire before the content was loaded. If there's a simpler way to achieve this, let me know, but this works as well.

---

<div class="post-metadata">

**Author:** ![magdaaniol](https://sea2.discourse-cdn.com/flex020/user_avatar/support.prodi.gy/magdaaniol/32/2787_2.png) [@magdaaniol](https://support.prodi.gy/u/magdaaniol)\
**Post date:** [December 18, 2025, 10:05am UTC](https://support.prodi.gy/t/custom-javascript-not-shown-when-moving-to-new-task/7637/2 "2025-12-18T10:05:15Z")

</div>

Hi @helmiina,

The solution is to listen to `prodigyupdate` event to display the reason. This always fires on task updates (including the call to `window.prodigy.update()`) and it guarantees the `content` is available, so it eliminates the need for the async polling.

```python
 document.addEventListener('prodigyupdate', () => {
      const content = window.prodigy.content;
      if (!content || !content.combined_accept || !content.options) {
          return;
      }

      // Prevent infinite loop (see explanation below)
      if (content.reason) {
          return;
      }

      const acceptValues = content.combined_accept;
      const options = content.options;

      const reasonsObj = options.filter(el => acceptValues.includes(el.id));
      const reasons = reasonsObj.map(el => el.text.toLowerCase()).join(", ");
      console.log("reasons: " + reasons);

      window.prodigy.update({ reason: "This task was rejected in review for reason(s): " + reasons });
  });

```

When you call `window.prodigy.update()`, Prodigy fires another `prodigyupdate` event (so other scripts can react to the change). Without the check `if (content.reason) return;` this would cause an infinite loop.

Importantly, for this fix to work you'd need to upgrade to **Prodigy 1.18.4**. In version 1.18.0, the `prodigyupdate` event had some reliability issues:

- It was fired from a component that re-renders frequently, causing it to sometimes fire multiple times per task or miss task changes entirely
- Events like `prodigysave` and `prodigyscriptload` didn't fire consistently in all scenarios

In versions 1.18.3 and 1.18.4, we fixed these and other issues related to event lifecycle.  
Without them, your `prodigyupdate` event listener may not work correctly across all tasks, in particular the first task.

---

<div class="post-metadata">

**Author:** ![helmiina](https://avatars.discourse-cdn.com/v4/letter/h/ee7513/32.png) [@helmiina](https://support.prodi.gy/u/helmiina)\
**Post date:** [December 18, 2025, 2:18pm UTC](https://support.prodi.gy/t/custom-javascript-not-shown-when-moving-to-new-task/7637/3 "2025-12-18T14:18:55Z")

</div>

Thanks for the reply,

I did initially try to work with `prodigyupdate` but always ended up in an infinite loop. I'll try updating our prodigy version and trying your code, thank you!