# Perspective Checkbox with UDT Parameter

**URL:** <https://forum.inductiveautomation.com/t/perspective-checkbox-with-udt-parameter/30766>\
**Category:** Ignition Early Access\
**Created:** [December 17, 2019, 3:22pm UTC](https://forum.inductiveautomation.com/t/perspective-checkbox-with-udt-parameter/30766 "2019-12-17T15:22:06Z")\
**Posts on this page:** 1\
**Showing post:** 3

<div class="post-metadata">

**Author:** ![cmallonee](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/cmallonee/32/6416_2.png) [@cmallonee](https://forum.inductiveautomation.com/u/cmallonee)\
**Post date:** [December 17, 2019, 4:47pm UTC](https://forum.inductiveautomation.com/t/perspective-checkbox-with-udt-parameter/30766/3 "2019-12-17T16:47:06Z")

</div>

Good news and bad news.

**Bad news:**  
You can’t do what you’re trying to do, because UDT parameters are read-only through the binding dialog. This is because UDT parameters are used to construct the UDT, and changing the parameters causes the entire UDT to be rebuilt; something you really don’t want for large UDTs and/or large volumes of UDTs.

**Good news:**  
If this is absolutely important to you, you could use a change script on the checkbox to set the value of the parameter, but you should absolutely NOT use a binding against the parameter in conjunction with said change script as it will create an infinite loop and trash your Designer session.

```auto
# this should also keep your parameter as a string.
system.tag.writeBlocking([self.view.params.udtValue + "/Parameters.almEnabledHiHi"],[str(currentValue.value)])

```

As for your mention of transforms being one way:  
Transforms only work one way and will only ever be one way. Suppose you had a script transform; how would we run a script in reverse?

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