[英]Angular 4 - Using Asynchronous custom validators
我有以下代碼:
HTML:
<div [class]="new_workflow_row_class" id="new_workflow_row">
<div class="col-sm-6">
<label class="checkmark-container" i18n>New Workflow
<input type="checkbox" id="new-workflow" name="new-workflow" [(ngModel)]="new_checkbox" (click)="uncheckBox($event, 'edit')">
<span class="checkmark" id="new-workflow-checkmark" [class]="checkmark_class"><span id="new-workflow-checkmark-content"></span>{{checkmark_content}}</span>
</label>
<input type="text" *ngIf="new_checkbox" id="new_workflow_name" name="new_workflow_name" (keyup)="clearWorkflowError(true)" [(ngModel)]="new_workflow" placeholder="Enter Workflow Name">
<p [hidden]="!show_workflow_error && !workflowForm.errors" class="workflow-error" i18n>The workflow name already exists. Please use a different name.</p>
</div>
</div>
Component.ts:
duplicateWorkflowValidator(control: FormControl) {
console.log("this validator was called!");
clearTimeout(this.workflowTimeout);
return new Promise((resolve, reject) => {
if (this.new_workflow != '') {
this.workflowTimeout = setTimeout(() => {
this
.requestService
.findWorkflow(control.value)
.subscribe((results: any) => {
let data: any = results.data;
if (data.duplicate) {
resolve({ duplicateWorkflow: { value: control.value}})
}
else if (results.status == "OK") {
resolve(null);
}
})
;
}, 500);
}
else {
resolve(null);
}
})
}
在component.ts的內部構造函數中:
this.workflowForm = new FormGroup({
name: new FormControl(this.new_workflow, [
Validators.required,
], this.duplicateWorkflowValidator.bind(this))
});
我正在嘗試將此異步驗證器綁定到反應形式,但是它不起作用。 我想在工作流程窗體內使用plicatorWorkflowValidator,並在找到重復的工作流程時觸發錯誤消息。
我如何a)正確地將驗證器綁定到反應形式,b)訪問驗證器錯誤? 預先感謝,希望這是有道理的。
您正在將模板形式與反應形式混合在一起。 選擇一種方法。 在下面的示例中,我使用了反應形式。
試試這個簡化版本。 出於演示目的,當我鍵入test
,驗證器將失敗,但是當我鍵入其他任何內容時,驗證器將成功。 您需要將其更改為服務電話。
https://angular-sjqjwh.stackblitz.io
模板:
<form [formGroup]="myForm">
<div>
<div>
<input type="text" formControlName="name">
<div *ngIf="myForm.controls.name.hasError('duplicateWorkflow')">
Workflow already exists!
</div>
{{ myForm.controls.name.hasError('duplicateWorkflow') | json }}
</div>
</div>
</form>
零件
import { Component } from '@angular/core';
import { FormControl, FormGroup, Validators, Form, FormBuilder } from '@angular/forms';
@Component({
selector: 'my-app',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css']
})
export class AppComponent {
workflowTimeout: number = 0;
myForm: FormGroup;
constructor(private fb: FormBuilder) {
this.myForm = this.fb.group({
name: new FormControl('',
[Validators.required],
this.duplicateWorkflowValidator.bind(this))
});
}
duplicateWorkflowValidator(control: FormControl) {
console.log("this validator was called!");
return new Promise((resolve, reject) => {
if (control.value === 'test') {
this.workflowTimeout = setTimeout(() => {
resolve({ duplicateWorkflow: { value: control.value } })
}, 500);
}
else {
resolve(null);
}
});
}
}
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