angular-cn/packages/forms/src/form_builder.ts

99 lines
3.5 KiB
TypeScript

/**
* @license
* Copyright Google Inc. All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
import {Injectable} from '@angular/core';
import {AsyncValidatorFn, ValidatorFn} from './directives/validators';
import {AbstractControl, FormArray, FormControl, FormGroup} from './model';
/**
* @whatItDoes Creates an {@link AbstractControl} from a user-specified configuration.
*
* It is essentially syntactic sugar that shortens the `new FormGroup()`,
* `new FormControl()`, and `new FormArray()` boilerplate that can build up in larger
* forms.
*
* @howToUse
*
* To use, inject `FormBuilder` into your component class. You can then call its methods
* directly.
*
* {@example forms/ts/formBuilder/form_builder_example.ts region='Component'}
*
* * **npm package**: `@angular/forms`
*
* * **NgModule**: {@link ReactiveFormsModule}
*
* @stable
*/
@Injectable()
export class FormBuilder {
/**
* Construct a new {@link FormGroup} with the given map of configuration.
* Valid keys for the `extra` parameter map are `validator` and `asyncValidator`.
*
* See the {@link FormGroup} constructor for more details.
*/
group(controlsConfig: {[key: string]: any}, extra: {[key: string]: any}|null = null): FormGroup {
const controls = this._reduceControls(controlsConfig);
const validator: ValidatorFn = extra != null ? extra['validator'] : null;
const asyncValidator: AsyncValidatorFn = extra != null ? extra['asyncValidator'] : null;
return new FormGroup(controls, validator, asyncValidator);
}
/**
* Construct a new {@link FormControl} with the given `formState`,`validator`, and
* `asyncValidator`.
*
* `formState` can either be a standalone value for the form control or an object
* that contains both a value and a disabled status.
*
*/
control(
formState: Object, validator?: ValidatorFn|ValidatorFn[]|null,
asyncValidator?: AsyncValidatorFn|AsyncValidatorFn[]|null): FormControl {
return new FormControl(formState, validator, asyncValidator);
}
/**
* Construct a {@link FormArray} from the given `controlsConfig` array of
* configuration, with the given optional `validator` and `asyncValidator`.
*/
array(
controlsConfig: any[], validator?: ValidatorFn|null,
asyncValidator?: AsyncValidatorFn|null): FormArray {
const controls = controlsConfig.map(c => this._createControl(c));
return new FormArray(controls, validator, asyncValidator);
}
/** @internal */
_reduceControls(controlsConfig: {[k: string]: any}): {[key: string]: AbstractControl} {
const controls: {[key: string]: AbstractControl} = {};
Object.keys(controlsConfig).forEach(controlName => {
controls[controlName] = this._createControl(controlsConfig[controlName]);
});
return controls;
}
/** @internal */
_createControl(controlConfig: any): AbstractControl {
if (controlConfig instanceof FormControl || controlConfig instanceof FormGroup ||
controlConfig instanceof FormArray) {
return controlConfig;
} else if (Array.isArray(controlConfig)) {
const value = controlConfig[0];
const validator: ValidatorFn = controlConfig.length > 1 ? controlConfig[1] : null;
const asyncValidator: AsyncValidatorFn = controlConfig.length > 2 ? controlConfig[2] : null;
return this.control(value, validator, asyncValidator);
} else {
return this.control(controlConfig);
}
}
}