# Custom Action on Add

**URL:** https://community.glideapps.com/t/custom-action-on-add/67633
**Category:** Ask for Help
**Created:** [November 9, 2023, 2:39am UTC](https://community.glideapps.com/t/custom-action-on-add/67633 "2023-11-09T02:39:07Z")
**Posts on this page:** 1
**Showing post:** 5

<div class="post-metadata">

### Author: ![nathanaelb](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/nathanaelb/32/43079_2.png) [@nathanaelb](https://community.glideapps.com/u/nathanaelb)
#### Post date: [November 9, 2023, 4:01am UTC](https://community.glideapps.com/t/custom-action-on-add/67633/5 "2023-11-09T04:01:30Z")

</div>

> [@Dan\_San](#):
>
> Problem I have is that based on the input, I need to use relations and lookup to pull in some data and then based on that data I need to apply the IF/ELSE column  
> AND then insert that data into a text column using the “default value” function.

That won’t work. When you are on a Show Form Screen, whatever data you input in the fields doesn’t yet exist in any table until the user hits submit. So you cannot actually compute any of the data until it is submitted.

I think you might need to create a custom form to compute data before it is submitted, courtesy of Darren:

> [@How do I create a custom form?](https://community.glideapps.com/t/how-do-i-create-a-custom-form/25014):
>
> I’m just dropping this here so I have something to refer people to when they ask. This is a simple concept app (copyable), that demonstrates the following techniques: Building custom forms for adding and editing list items (as an alternative to the native forms provided by Glide) Preventing duplicate new entries using [User Specific Columns](https://docs.glideapps.com/all/reference/data-editor/user-specific-columns) and [Relations](https://docs.glideapps.com/all/reference/data-editor/computed-columns/relation-column) Enforcing mandatory input items The use of visibility conditions and user specific booleans to control user flow There is nothing particula…

---

_[View the full topic](https://community.glideapps.com/t/custom-action-on-add/67633)._