# Handling Required Inputs During Function Block Creation

**URL:** <https://community.br-automation.com/t/handling-required-inputs-during-function-block-creation/9270>\
**Category:** Programming\
**Tags:** automation-studio\
**Created:** [December 4, 2025, 8:56pm UTC](https://community.br-automation.com/t/handling-required-inputs-during-function-block-creation/9270 "2025-12-04T20:56:36Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![HansP](https://avatars.discourse-cdn.com/v4/letter/h/FF8800/32.png) [@HansP](https://community.br-automation.com/u/HansP)\
**Post date:** [December 4, 2025, 8:56pm UTC](https://community.br-automation.com/t/handling-required-inputs-during-function-block-creation/9270/1 "2025-12-04T20:56:36Z")

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When creating a Function Block, you can force the user to bind specific inputs  
otherwise, they will receive an error message when running Build.

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**Author:** ![alexander.hefner](https://dub1.discourse-cdn.com/brcommunity/user_avatar/community.br-automation.com/alexander.hefner/32/111_2.png) [@alexander.hefner](https://community.br-automation.com/u/alexander.hefner)\
**Post date:** [December 5, 2025, 5:40am UTC](https://community.br-automation.com/t/handling-required-inputs-during-function-block-creation/9270/2 "2025-12-05T05:40:55Z")

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Hi,

as I understood your question (“throw a compiler error if a function block instance element variable is not assigned to a external variable from the calling task”), this is not possible as I know.

Best regards!

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**Author:** ![kovarj](https://dub1.discourse-cdn.com/brcommunity/user_avatar/community.br-automation.com/kovarj/32/537_2.png) [@kovarj](https://community.br-automation.com/u/kovarj)\
**Post date:** [December 16, 2025, 9:03am UTC](https://community.br-automation.com/t/handling-required-inputs-during-function-block-creation/9270/3 "2025-12-16T09:03:52Z")

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Hi @HansP, I have marked the reply of Alex as an answer on your issue. If you have any additional questions or new findings, feel free to continue the discussion.