Add DropdownMenuFormField.errorBuilder by bleroux · Pull Request #179345 · flutter/flutter

bleroux · 2025-12-02T15:31:59Z

Description

This PR adds the DropdownMenuFormField.errorBuilder property which makes it possible to customize the widget used to display the error message.

This is a follow-up to #162255 which added the errorBuilder property to other form fields.

Related Issue

Fixes DropdownMenuFormField is missing an errorBuilder property

Tests

Updates 5 tests.
Adds 1 test.

gemini-code-assist

Code Review

This pull request adds the errorBuilder property to DropdownMenuFormField, allowing for custom error widget display, which aligns it with other form fields. The implementation is sound and the accompanying tests are thorough, covering the new functionality and updating existing tests to reflect the refactoring of decoration properties. I have one suggestion to simplify the decoration builder logic for better readability.

packages/flutter/lib/src/material/dropdown_menu_form_field.dart

SamuelGadiel · 2025-12-12T13:42:56Z

Can we implement the errorBuilder to the FormField as well?
They have added the parameter to the FormField, but never used it there
So when we try to use the FormField directly, we can pass the errorBuilder, but it's never used
The same for the validator. When an error occurs the validator returns the string, but it's never shown

I supose this parameter has been added only for the FormField implementations to use it
Just like you implemented in DropdownMenuFormField
But could we improve it to be used with the base class as well?

Edit:
I have created a dedicated issue for this. I would love for your help with it
#179794

justinmc

LGTM 👍

packages/flutter/test/material/dropdown_menu_form_field_test.dart

Roll Flutter from 13b2b91 to 01d37bc (74 revisions) flutter/flutter@13b2b91...01d37bc 2026-01-07 [email protected] Replace Hybrid Composition wiki page with dev-facing content (flutter/flutter#180642) 2026-01-07 [email protected] Improve code quality in `FlutterActivityTest.java` (flutter/flutter#180585) 2026-01-07 [email protected] Roll Dart SDK to 3.11.0-296.1.beta (flutter/flutter#180633) 2026-01-07 [email protected] Bump target Windows version to 10 (flutter/flutter#180624) 2026-01-07 [email protected] Run hook_user_defines and link_hook integration tests on CI (flutter/flutter#180622) 2026-01-07 [email protected] Fix division by zero in RenderTable intrinsic size methods (flutter/flutter#178217) 2026-01-07 [email protected] Remove more `requires 24` anotations (flutter/flutter#180116) 2026-01-07 [email protected] Roll Skia from 3971dbb85d45 to c5359a4d720e (1 revision) (flutter/flutter#180631) 2026-01-07 [email protected] Fix TabBar.image does not render at initialIndex for the first time (flutter/flutter#179616) 2026-01-07 [email protected] Roll Skia from 1e7ad625f6f7 to 3971dbb85d45 (3 revisions) (flutter/flutter#180627) 2026-01-07 [email protected] Unpin DDS (flutter/flutter#180571) 2026-01-07 [email protected] Fix DropdownMenuEntry.style not resolved when entry is highlighted (flutter/flutter#178873) 2026-01-07 [email protected] Remove unnecessary `@RequiresApi24` annotations from FlutterFragment methods (flutter/flutter#180117) 2026-01-07 [email protected] Roll Skia from 7fc63228056b to 1e7ad625f6f7 (1 revision) (flutter/flutter#180616) 2026-01-07 [email protected] Roll Fuchsia Linux SDK from QfR2ZFZ5kGTD3raO3... to dTvN_JVSCfGFRasvH... (flutter/flutter#180612) 2026-01-07 [email protected] [ Widget Preview ] Add support for `dart:ffi` imports (flutter/flutter#180586) 2026-01-07 [email protected] Roll Skia from eec90000a899 to 7fc63228056b (2 revisions) (flutter/flutter#180608) 2026-01-07 [email protected] Add --web-define flag for template variable injection in Flutter web builds (flutter/flutter#175805) 2026-01-07 [email protected] docs(engine): update rbe notes (flutter/flutter#180599) 2026-01-06 [email protected] Roll Skia from b6249496c230 to eec90000a899 (3 revisions) (flutter/flutter#180602) 2026-01-06 [email protected] Forward proxy 404 responses to client (flutter/flutter#179858) 2026-01-06 [email protected] Roll Dart SDK from 40a8c6188f7f to d2e3ce177270 (1 revision) (flutter/flutter#180598) 2026-01-06 [email protected] Restore CLI precedence for web headers and HTTPS over web_dev_config.yaml (flutter/flutter#179639) 2026-01-06 [email protected] Roll Skia from f5d9da13d56d to b6249496c230 (1 revision) (flutter/flutter#180596) 2026-01-06 [email protected] Enable misc leak tracking (flutter/flutter#176992) 2026-01-06 [email protected] [hooks] Don't require NDK for Android targets (flutter/flutter#180594) 2026-01-06 [email protected] [skia] Disable legacy non-const SkData APIs (flutter/flutter#179684) 2026-01-06 [email protected] Fix/ios share context menu (flutter/flutter#176199) 2026-01-06 [email protected] Roll Skia from b970aeffa66f to f5d9da13d56d (5 revisions) (flutter/flutter#180588) 2026-01-06 [email protected] Manually bump dependencies (flutter/flutter#180509) 2026-01-06 [email protected] Roll Dart SDK from 8150be8a0e48 to 40a8c6188f7f (2 revisions) (flutter/flutter#180582) 2026-01-06 [email protected] Roll Packages from 12eb764 to d3f860d (2 revisions) (flutter/flutter#180581) 2026-01-06 [email protected] Roll Fuchsia Test Scripts from MHF-UAfO6sVKqSEYk... to nR2ESa1Gd8yPcWo06... (flutter/flutter#180578) 2026-01-06 [email protected] Add tooltip support to PlatformMenuItem and PlatformMenu. (flutter/flutter#180069) 2026-01-06 [email protected] Add DropdownMenuFormField.errorBuilder (flutter/flutter#179345) 2026-01-06 [email protected] Roll Skia from 1845397e11ba to b970aeffa66f (2 revisions) (flutter/flutter#180566) 2026-01-06 [email protected] Don't embed unreferenced assets (flutter/flutter#179251) 2026-01-06 [email protected] Improve documentation about ValueNotifier's behavior (flutter/flutter#179870) 2026-01-06 [email protected] Roll Skia from 904ba00331ca to 1845397e11ba (5 revisions) (flutter/flutter#180558) 2026-01-06 [email protected] Roll Dart SDK from 2fb9ad834c4d to 8150be8a0e48 (1 revision) (flutter/flutter#180557) 2026-01-06 [email protected] Roll Skia from 98c042dde68c to 904ba00331ca (3 revisions) (flutter/flutter#180550) 2026-01-06 [email protected] Roll Dart SDK from ba9f7f790966 to 2fb9ad834c4d (2 revisions) (flutter/flutter#180548) 2026-01-06 [email protected] Roll Fuchsia Linux SDK from ubBGcRaAKWKihQ4ac... to QfR2ZFZ5kGTD3raO3... (flutter/flutter#180547) 2026-01-06 [email protected] Make sure that a DraggableScrollableSheet doesn't crash in 0x0 enviro… (flutter/flutter#180433) 2026-01-06 [email protected] Make sure that a ColorFiltered doesn't crash 0x0 environment (flutter/flutter#180307) 2026-01-06 [email protected] Make sure that a FadeInImage doesn't crash in 0x0 environment (flutter/flutter#180495) ...

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bleroux requested a review from justinmc December 2, 2025 20:55

bleroux force-pushed the add_DropdownMenuFormField.errorBuilder branch from 1a961aa to 9f2de72 Compare December 10, 2025 22:00

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bleroux force-pushed the add_DropdownMenuFormField.errorBuilder branch from 9f2de72 to 3aff74d Compare January 6, 2026 13:09

bleroux added 3 commits January 6, 2026 14:13

Add DropdownMenuFormField.errorBuilder

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bleroux force-pushed the add_DropdownMenuFormField.errorBuilder branch from 3aff74d to d03c0a9 Compare January 6, 2026 13:14

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bleroux commented Dec 2, 2025

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SamuelGadiel commented Dec 12, 2025 •

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bleroux commented Dec 2, 2025

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Tests

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SamuelGadiel commented Dec 12, 2025 •

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