AngularJS form
The AngularJS framework provides support for HTML forms and form inputs.
An Angular form coordinates a set of data-bound user controls, tracks changes, validates input, and presents errors.
Contents
Summary
- Build an Angular form with a component and template
- Two-way data bind with [(ngModel)] syntax for reading and writing values to input controls
- Track the change state and validity of form controls using ngModel in combination with a form
- Provide strong visual feedback using special CSS classes that track the state of the controls
- Display validation errors to users and enable/disable form controls
- Use template reference variables for sharing information among HTML elements
Template-driven forms
You can create forms by writing templates in the Angular template syntax with the form-specific directives and techniques.
Working with forms
If you simply want to get the value of a form input, use ngModel.
If you want to get the state of form input, use a form control.
Inputs can be grouped together using group controls.
Form control
A form control is an HTML form input element, such as input (HTML element). AngularJS provides input binding for programmatic handling of form controls, such as input validation.
Form group control
A form group control allows the grouping together of two or more form controls.
FormBuilder
FormBuilder is an Angular2 feature for working with forms.
Example
import { Component } from 'angular2/common';
import { FORM_DIRECTIVES } from 'angular2/common';
import { MATERIAL_DIRECTIVES } from 'ng2-material/all';
@Component ({
selector: 'some-form',
template: `
<div>
<form #userForm="ngForm" #nameGroup="ngForm">
<div ngControlGroup="name" #nameGroup="ngForm">
<md-input-container [class.err]="!firstName.valid">
<label>First Name</label>
<input required md-input [(ngModel)]="user.firstName" #firstName="ngForm"
placeholder="Enter first name"
class="mdl-textfield__input" type="text">
</md-input-container>
... etc....
</div>
<div class="mdl-card__actions">
<button type="submit" (click)="cancelled.emit(selectedItem)"
class="mdl-button mdl-js-button mdl-js-ripple-effect">Cancel</button>
<button type="submit" (click)="cancelled.emit(selectedItem)"
class="mdl-button mdl-js-button mdl-button--colored mdl-js-ripple-effect">
</div>
</form>
`,
directives: [ FORM_DIRECTIVES ],
styles: [`...`]
})
export class FormComponent {
constructor(private _builder: FormBuilder) {
this.userForm = _builder.group ({
nameGroup: _builder.group ({
firstName: [this.user.firstName, Validators.required],
lastName: [this.user.lastName, Validators.required]
})
})
}
}
