[英]Inject a service in a custom validator in Angular2
I try to use a service in a custom validator to check if a username already exists. 我尝试在自定义验证器中使用服务来检查用户名是否已存在。
import {Component} from 'angular2/core';
import {
Control,
ControlGroup,
FormBuilder
} from "angular2/common";
import {CharacterService} from "./character-service";
@Component({
selector: 'register-character-form',
template: `
<h2 class="ui header">A new adventurer is coming...</h2>
<form (ngSubmit)="register()" [ngFormModel]="characterForm" class="ui form">
<div class="field">
<label>Nom</label>
<input ngControl="name">
</div>
<button type="submit" class="ui button">Enter in the adventure</button>
</form>
`,
providers: [CharacterService]
})
export class RegisterCharacterFormCmp {
characterForm: ControlGroup;
name: Control;
constructor(private _characterService: CharacterService, fb: FormBuilder) {
this.name = fb.control('', this.characterNameValidator);
this.characterForm = fb.group({
name: this.name
});
}
register(): void {
//TODO: To implement
}
// Not works, this binds the control
characterNameValidator(control: Control) {
return this._characterService.isCharacterNameAlreadyExists(control.value) ? {nameCharacterAlreadyExistsError: true} : null;
}
}
It doesn't work. 它不起作用。 In the characterNameValidator, 'this' references the control and not my class. 在characterNameValidator中,'this'引用控件而不是我的类。 The service is undefined. 该服务未定义。 How can I use my service in the validator ? 如何在验证器中使用我的服务?
More globally, how can I pass arguments in a custom validator ? 更全局,我如何在自定义验证器中传递参数?
您可以使用箭头功能来保持上下文相同。
this.name = fb.control('', (control: Control) => this.characterNameValidator(control));
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.