let component=this.target.createComponent(factory, 0); let ctrl=this.form.controls["age"]; component.instance.writeValue(ctrl.value); //需要手动去调用 writeValue, registerOnChange, registerOnTouched, 如果可以直接加上 formControlName 指令,就方便多了. component.instance.registerOnChange((v)=>{ ctrl...
Validatorsdynamically using the SetValidators or SetAsyncValidators. This method is available toFormControl,FormGroup&FormArray. There are many use cases where it is required to add/remove validators dynamically to a FormControl or FormGroup. Usually when you have a Form Field, whose value depend...
import React, { Component } from 'react'; import { FormBuilder, FieldGroup, FieldControl, Validators, } from "react-reactive-form"; const TextInput = ({ handler, touched, hasError, meta }) => ( <div> <input placeholder={`Enter ${meta.label}`} {...handler()}/> <span> {touched ...
fb.control(''); this.questions.push(newQuestion); } removeQuestion(index: number) { this.questions.removeAt(index); } 2.2 Adding and Removing Form Controls One of the key advantages of FormArray is its ability to dynamically add or remove form controls. This is often required when users...
In this example we have created a FormGroup that contains FormControl. Now look into the code. this.userForm = this.formBuilder.group({ name: '', age: '' }); setName() { this.userForm.get('name').setValue('Mahesh'); } setAge() { this.userForm.get('age').setValue(25); }...
Inside createGroup, we loop through these items and create a new control for each one. We then add these dynamically created controls to the form group, ready for consumption by our dynamic fields. Let’s declare and export this component inside of our DynamicFormModule: // ... import { ...
This page will walk through Angular FormArray example. Angular FormArray tracks the value and validity state of an array of FormControl, FormGroup or FormArray instances.
signupForm:FormGroup; FirstName:string=""; LastName:string=""; Email:string=""; Password:string=""; constructor(private frmbuilder:FormBuilder){ this.signupForm=frmbuilder.group({ /*fname:new FormControl(), lname:new FormControl(), email:new FormControl(), password:new ...
262 What is the purpose of FormBuilder? 263 How do you verify the model changes in forms? 264 What are the state CSS classes provided by ngModel? 265 How do you reset the form? 266 What are the types of validator functions? 267 Can you give an example of built-in validators? 268 ...
Instead of using template-driven forms, use Reactive Forms to dynamically add controls. To learn more about Reactive Forms, refer to this documentation. The component containing the form is responsible for using the FormBuilder class along with the FormGroup class and the addControl() method to ...