Component var updates in streaming API inside action block prepends _model.

[Jotte92]

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• I give permission for members of the FlutterFlow team to access and test my project for the sole purpose of investigating this issue.

Current Behavior

Streaming API call that is inside a component level action block will prepend "_model." to the function.

(onMessageInput) async { _model.updateVariableAtIndex(

This does not throw an error in Flutterflow but it will when pulling to VS code.

Expected Behavior

Does not need to prepend "_model." as its already inside the model.

Steps to Reproduce

1. Create streaming API request
2. Create component state variable
3. Create component level actionblock
4. Add API call to action block and update the variable onMessage

Reproducible from Blank

• The steps to reproduce above start from a blank project.

Bug Report Code (Required)

ITFfksmBw41Pm9tc1r6Jb8BGnmYWH0ccTOURiO0bFDsdF4iuPOxzacnCXE9tYN+rTAhfKEWJhmoywdbLhtjlNPUoORKaRa0/+s5ubTzzWni/aoSxBsyNOHZQEeNWGU+P07ejuQl+ItducnMsw06uBPKicHbXHqX7Zwh9f6PHaOI=

Visual documentation

Environment

- FlutterFlow version: v5.2.9
- Platform: VS code
- Browser name and version: Brave Version 1.75.181
- Operating system and version affected: MacOS 15.3.1

Additional Information

No response

[Alezanello]

Hello! 😊

One important thing to keep in mind is that Action Blocks (App Block or Component Block) don’t have direct access to the model they are implemented in. This means that trying to update a component’s state directly from an Action Block will likely result in failure.

Instead, you might consider using AppState, as it doesn’t require direct access to any specific model and can help you achieve the desired behavior.

[Jotte92]

Hello Alezanello,

Thank you for your response! Sorry if i'm misunderstanding how states are handled.

My issue seems to be coming from trying to update a component state that is a list of a custom data type from within a streaming API call in the block, flutterflow is prepending _model. to the function when it should not be. I think this may be specific to streaming API calls which i'm trying to do.

Please take a look at my code to see.
ITFfksmBw41Pm9tc1r6Jb8BGnmYWH0ccTOURiO0bFDsdF4iuPOxzacnCXE9tYN+rTAhfKEWKr3wHzN7Gj+L+GvoFPQWVGIRe/7lcVgvMQnO/aoSxBsyNOHZQEeNWGU+P07ejuQl+ItducnMsw06uBPKicHbXHqX7Zwh9f6PHaOI=

If I download my code and remove the _model. manually, this solves the problem and my code will run, updating the component state. However, I get UI refresh issues, only the first chunk will display on my screen the others don't update, although all chunks are processed and stored in component state, so it can be accessed.

I have now moved all the logic to AppState, which has solved my issue as you suggested.

[Alezanello]

Hello!!

Could you try instead of using the "As Data Type" option directly. select the "Server Sent Event Data JSON" option from the "Response Stream Message Options" dropdown, then select "To Data Type" and then select the data type.

try to save it this way!

[Jotte92]

Hey,

This is basically how I do it, i'm streaming a chatGPT response into a "ChatItem" data type (which contains a 'content' field) from the server sent event JSON as a string and appending it to the previous chunk with combine text.

Because i'm updating a component variable that is a list of ChatItem data on each chunk flutterflow uses the _model.updateVarAtIndex function, which would be correct if the API call was in the widget, but because it's in the component block it shouldn't be using _model. it has direct access to updateVarAtIndex.

I really think this is a bug, as VS code picks up the error but flutterflow doesn't, and if I remove _model. it runs.

[github-actions]

This issue is stale because it has been open for 7 days with no activity. If there are no further updates, a team member will close the issue.