Adds the `isFieldTree` utility that allows users to assert whether a value is a field tree. This is something that has come up on Material recently and will be useful for users as well.
Fixes#69984.
This enables the use of the `experimentalWebMcpTool` option on signal forms and implicitly declares a WebMCP tool based on the form data model. This is an experiment inspirted by the WebMCP declarative forms API to see if Angular's framework-level knowledge of the form's declarative data model can produce higher quality WebMCP tools than the web standard can on its own with less effort from the developer.
Example:
```typescript
// main.ts
import {bootstrapApplication} from '@angular/platform-browser';
import {provideExperimentalWebMcpForms} from '@angular/forms';
import {MyComp} from './form';
bootstrapApplication(MyComp, {
providers: [
// Activate the feature.
provideExperimentalWebMcpForms(),
],
});
```
```typescript
// form.ts
import {Component, signal} from '@angular/core';
import {form} from '@angular/forms';
@Component({ /* ... */ })
export class MyComp {
private readonly f = form(signal({
firstName: '',
lastName: '',
}), {
// Implicitly creates a WebMCP tool named `createUser` which accepts a `firstName` and `lastName` as parameters.
experimentalWebMcpTool: {
name: 'createUser',
description: 'Creates a user with the given name.',
},
// Invokes the submit action when the agent calls the WebMCP tool.
submission: {
action: () => {
console.log('User clicked submit, or agent called the tool!');
},
},
});
// ...
}
```
Reoves the `parseErrors` property on `FormUiControl` and instead
introduces a new utility `transformedValue` that automatically handles
synchronizing the raw value and model value using the given `parse` and
`format` functions. It also automates the reporting of `parseErrors` to
the `FormField`, simplifying the API surface
Refactors the `ɵɵcontrolCreate` and `ɵɵcontrol` instructions to delegate control logic to the forms package via new `ɵngControlCreate` and `ɵngControlUpdate` lifecycle hooks. Previously, the logic for binding form state to native elements and custom controls was hardcoded within `@angular/core`.
**Compiler Changes:**
- Introduces a new compilation phase `specializeControlProperties` (in `control_directives.ts`).
- This phase detects properties named `formField` and specializes them into `ControlCreate` and `Control` IR opcodes.
- These opcodes emit `ɵɵcontrolCreate` and `ɵɵcontrol` instructions, respectively.
**Runtime Changes:**
- `ɵɵcontrolCreate` acts as the creation phase. It locates the control directive and invokes its `ɵngControlCreate` method.
- `ɵɵcontrol` acts as the update phase, and invokes the control directive's `ɵngControlUpdate` method (if present).
- Introduces a `passThroughInput` configuration in `ControlFeature`. This specifies the input name (e.g., `formField`) that triggers the control. If the runtime detects that this input is bound to multiple targets (e.g., the `FormField` directive *and* the host component), the control is flagged as "pass-through". In this state, `ɵngControlCreate` returns a no-op update function, deferring responsibility to the other consumer (e.g., the component managing the field itself).
**Forms Changes:**
- `FormField` directive implements `ɵngControlCreate` and `ɵngControlUpdate`.
- Inside this hook, `FormField` determines the type of control it is attached to (Native, CVA, or Custom Signal Control) and delegates to the appropriate handler (`nativeControlCreate`, `cvaControlCreate`, or `customControlCreate`).
- Consolidates all form binding logic within `@angular/forms/signals`, enabling support for new `FormValueControl` and `FormCheckboxControl` interfaces.
- Reorganizes the codebase by moving `FormField` from `api/` to `directive/` and splitting the binding logic into semantic pieces:
- `control_native.ts`, `control_cva.ts`, and `control_custom.ts` contain the specific handlers for each control type.
- `native.ts` and `select.ts` provide helpers for native element discovery and select-specific synchronization.
- `bindings.ts` manages the tracking and application of property/attribute bindings.
This completes the rename started in #66136. `[field]` is too generic of
a selector for the forms system to own, and likely to cause naming
collisions with existing components. Therefore it is being renamed to
`[formField]`
This will replace the `[field]` directive, since `[field]` is a very
generic name for signal forms to commandeer
refactor(forms): hook up `formField` directive in compiler
Hooks up the `formField` direcive to get the same treatment as the
`field` directive in the compiler.
apply updated formatting
This PR makes a number of changes to the metadata API to address design
flaws in the previous API. Some of the changes include:
- Replaces the previous `MetadataKey` and `AggregateMetadataKey` with a
single unified `MetadataKey` that is used for all metadata.
- The new `MetadataKey` is only defined for fields that explicitly set
it in their schema logic
- All metadata now has reducer / aggregate behavior
- The new `MetadataKey` has an option to create a managed key which
wraps the result of its computed aggregate into some other structure
such as a `Resource` or `linkedSignal`
- There are now two APIs to create metadata keys
- `createMetadataKey` for pure computed metadata
- `createManagedMetadataKey` for metadata that manages its computation
internally
Adds a DI configuration option for signal forms that allows the
developer to specify CSS classes that should be automatically added
by the `Field` directive based on the field's status.
The `debounce()` rule allows developers to control when changes to a
form control are synchronized to the form model.
This feature necessitated some changes to `FieldState`:
* `controlValue` is a new signal property that represents the current
value of a form field as it appears in its corresponding control.
* `value` conceptually remains unchanged; however, its value may lag
behind that of `controlValue` if a `debounce()` rule is applied.
The `debounce()` rule essentially manages when changes to `controlValue` are
synchronized to `value`. The intent is that an expensive or slow
validation rule can react to the debounced `value`, rather than a more
frequently changing `controlValue`.
Directly updating `value` immediately updates `controlValue`, and cancels any
pending debounced updates.
When multiple `debounce()` rules are applied to the same field, the last
currently active rule is used to debounce an update. These rules are
applied to child fields as well, unless they override them with their
own rule.
Moves the control directive under api/ since it is part of the public
API. Also removes the interop abstract control from the public API
PR Close#63616
This commit introduces an experimental version of a new signal-based forms API for Angular. This new API aims to explore how signals can be leveraged to create a more declarative, intuitive, and reactive way of handling forms.
The primary goals of this new signal-based approach are:
* **Signal-centric Design:** Place signals at the core of the forms experience, enabling a truly reactive programming model for form state and logic.
* **Declarative Logic:** Allow developers to define form behavior, such as validation and conditional fields, declaratively using TypeScript. This moves logic out of the template and into a typed, testable schema.
* **Developer-Owned Data Model:** The library does not maintain a copy of data in a form model, but instead read and write it via a developer-provided `WritableSignal`, eliminating the need for applications to synchronize their data with the form system.
* **Interoperability:** A key design goal is seamless interoperability with existing reactive forms, allowing for incremental adoption.
* **Bridging Template and Reactive Forms:** This exploration hopes to close the gap between template and reactive forms, offering a unified and more powerful approach that combines the best aspects of both.
This initial version of the experimental API includes the core building blocks, such as the `form()` function, `Field` and `FieldState` objects, and a `[control]` directive for binding to UI elements. It also introduces a schema-based system for defining validation, conditional logic, and other form behaviors.
Note: This is an early, experimental API. It is not yet complete and is subject to change based on feedback and further exploration.
Co-authored-by: Kirill Cherkashin <kirts@google.com>
Co-authored-by: Alex Rickabaugh <alxhub@users.noreply.github.com>
Co-authored-by: Leon Senft <leonsenft@users.noreply.github.com>
Co-authored-by: Dylan Hunn <dylhunn@gmail.com>
Co-authored-by: Michael Small <michael-small@users.noreply.github.com>
PR Close#63408
Kristiyan Kostadinov