validate(c: FormControl): {[key: string]: any} { // 省略 } } 我们可以看到要实现一个表单控件的话,要实现ControlValueAccessor这样一个接口。这个接口顾名思义是用于写入控件值的,它是一个控件和原生 DOM 元素之间的桥梁,通过实现这个接口,我们可以对原生 DOM 元素写入值。而这个接口需要实现三个必选方法...
下图是Angular 表单控件如何通过ControlValueAccessor来和原生表单控件交互的(译者注:formControl和你写的或者 Angular 提供的CustomControlValueAccessor两个都是要绑定到 native DOM element 的指令,而formControl指令需要借助CustomControlValueAccessor指令/组件,来和 native DOM element 交换数据。): 再次强调,不管是使用...
_checkAllValuesPresent(value: any):void{this._forEachChild((control: AbstractControl, name: string) =>{if(value[name] ===undefined) {thrownewError(`Must supply a valueforform controlwithname: '${name}'.`); } }); } 该方法内部通过_forEachChild()遍历内部的 FormControl 控件,来确保我们在...
design complexity: majorfeatureIssue that requests a new featurefeature: under considerationFeature request for which voting has completed and the request is now under considerationforms: ControlValueAccessorforms: Controls APIIssues related to AbstractControl, FormControl, FormGroup, FormArray.state: Needs...
* @param obj The new value for the element */writeValue(obj:any):void;/** * @description * Registers a callback function that is called when the control's value * changes in the UI. * * This method is called by the forms API on initialization to update the form ...
ControlValueAccessor interface. By doing so, you're telling Angular "how to access the value of your control" (hence the name). Or in simple terms: What to do, when you put a formControlName on an element, that doesn't naturally have a value associated ...
control.setValue(newValue, {emitModelToViewChange: false}); }); // setup a listener for changes on the Angular formControl // and set this value to the native control // 设置 Angular 表单控件值更新监听器,每当 Angular 表单控件值更新,原生控件值也更新 ...
Angular 表单控件值也更新valueAccessor.registerOnChange((newValue:any)=>{control.setValue(newValue,{emitModelToViewChange:false});});// setup a listener for changes on the Angular formControl// and set this value to the native control// 设置 Angular 表单控件值更新监听器,每当 Angular 表单控件...
On this page we will provide FormControl.setValue() examples. The FormControl.setValue() sets a new value to this control. Find the method declaration. setValue(value: any, options: { onlySelf?: boolean; emitEvent?: boolean; emitModelToViewChange?: boolean; emitViewToModelChange?: ...
Angular Strongly typed forms in Angular Registering form groups in Angular Form control validation Making a custom form control Nesting form groups in Angular Adding asynchronous data to the form How to add a FormControl to a FormGroup How to set a FormGroup value What is FormBuilder in ...