# Expression Input on a Map Transform

**URL:** <https://forum.inductiveautomation.com/t/expression-input-on-a-map-transform/114508>\
**Category:** Ignition\
**Tags:** ignition83, perspective\
**Created:** [March 16, 2026, 7:13pm UTC](https://forum.inductiveautomation.com/t/expression-input-on-a-map-transform/114508 "2026-03-16T19:13:58Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![dkhayes117](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/dkhayes117/32/68344_2.png) [@dkhayes117](https://forum.inductiveautomation.com/u/dkhayes117)\
**Post date:** [March 16, 2026, 7:43pm UTC](https://forum.inductiveautomation.com/t/expression-input-on-a-map-transform/114508/2 "2026-03-16T19:43:00Z")

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I tested this, and it seems that with an expression mapping, `{value}` is not a valid identifier in the expression.

Changing `{value}` to `{view.custom.tempF}` in each expression still did not work, which I figured should work. Adding one of the expressions to the fallback value, shows that the first expression is evaluating to `true`. 🤔

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/2/a/2a28d34ac313f17a7ad00180470f2c8fd9348d52.png)

check these threads out for more details  
[Transform Map Expression Not working properly - Ignition - Inductive Automation Forum](https://forum.inductiveautomation.com/t/transform-map-expression-not-working-properly/105780/3)  
[Expression to color/StyleClass map transform example - Ignition - Inductive Automation Forum](https://forum.inductiveautomation.com/t/expression-to-color-styleclass-map-transform-example/34814)

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