Imported Data Type from Library Project is Treated as Integer in Page Parameters

[diegoserranobst]

Can we access your project?

• 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

When using a custom Data Type imported from a library project (e.g., institucionTemplateDT), it is incorrectly recognized as an Integer when passed as a page parameter.

Inside the parameter definition UI, the correct Data Type appears selectable. However, once the parameter is used in the runtime preview or binding, it behaves as if it were a primitive value (Integer) instead of the expected complex object. This causes runtime errors and prevents proper data passing between pages.

Expected Behavior

Imported Data Types should retain their structure and be usable in page parameters just like local Data Types. Specifically:

The parameter should appear and behave as a structured object of the defined Data Type.

Binding and navigation should treat the parameter as an object, not as a primitive.

Steps to Reproduce

1. Create a new blank project.
2. Convert it to a library project.
3. Create a custom Data Type (e.g., institucionTemplateDT) in the library.
4. Publish the changes.
5. Create a new blank test project.
6. Import the library as a dependency.
7. Create a new page that accepts a page parameter of type institucionTemplateDT.
8. On the main page of the test project, add a button.
9. Add a Navigate action from the button to the new page, passing an object for the parameter.
10. Run the project and click the button.
11. Observe that the parameter is treated as an Integer, not as a structured object.

Reproducible from Blank

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

Bug Report Code (Required)

IT4WlcmAsIh2rsdY7rqBYPlagiQsJlw1bZ03lMNxTks0IqrnOrYPXfikSEpWZ9+kTHxcL2D9rD007s6MhtnuA+UpOROabKY9/6p2Sg3MYEKmVbqXC86ZdmsnL5pJJVyY0cORkCN+AMFtWiUQ20+qB+nLZDbUNLrGIVQjLv+iVbPDp3eqQ0SLb3kNh1JWeC/v

Visual documentation

Environment

- FlutterFlow version: v6.0.21 (released June 17, 2025)
- Platform: Web
- Browser: Chrome 125.0.0.0
- OS: Linux Mint 21.3
- Flutter version: 3.27.3

Additional Information

This bug blocks the ability to modularize UI into libraries and reuse complex data structures. It forces a workaround using App State or custom serialization, which defeats the purpose of Data Type reuse across projects.

[Juansarmi]

Hi! I'm sorry you're experiencing this issue. I've been able to reproduce the error and will be forwarding it to our engineering team so they can investigate it further.

In the meantime, I noticed that although the debug console interprets the DataType parameter as an integer, I didn’t encounter any issues when using it. I was able to add it to an app state, assign values, and use them within a page without any problems.

I’ll keep you posted as soon as I have any updates.

Best regards

[diegoserranobst]

@Juansarmi
Update – This is a critical blocking bug.
When passing an object of a Data Type defined in a library project (institucionTemplateDT) as a page parameter, the object is received as null in the destination page. This breaks navigation-based data passing and completely blocks modular project architectures based on shared UI libraries.
Please prioritize this. Workarounds like App State or recreating the object manually defeat the purpose of reusable UI modules.

[diegoserranobst]

@Juansarmi just doble checking. You was able to pass as page parameter?

[Juansarmi]

Hi again!
Yes, I’ve been able to use the datatype as a parameter.
In any case, the issue is currently being investigated by the engineering team, and I’ll let you know as soon as there are any updates.
Best regards

[diegoserranobst]

@Juansarmi I can confirm now the parameter are passing between pages and can be used. So now is just a debug panel issue.
Thanks