我正在使用Angular反应形式和Angular材料。 我的代码运行良好。 但是我想一次显示一个错误
我的.html文件代码
<form [formGroup]="accountDetailsForm" novalidate (ngSubmit)="onSubmitAccountDetails(accountDetailsForm.value)">
<mat-form-field class="full-width">
<input matInput maxlength="25" placeholder="Username" formControlName="username" required>
<mat-error *ngFor="let validation of account_validation_messages.username">
<mat-error class="error-message" *ngIf="accountDetailsForm.get('username').hasError(validation.type) && (accountDetailsForm.get('username').dirty || accountDetailsForm.get('username').touched)">{{validation.message}}</mat-error>
</mat-error>
</mat-form-field>
<mat-form-field class="full-width">
<input matInput type="email" placeholder="Email" formControlName="email" required>
<mat-error *ngFor="let validation of account_validation_messages.email">
<mat-error class="error-message" *ngIf="accountDetailsForm.get('email').hasError(validation.type) && (accountDetailsForm.get('email').dirty || accountDetailsForm.get('email').touched)">{{validation.message}}</mat-error>
</mat-error>
</mat-form-field>
<div formGroupName="matching_passwords">
<mat-form-field class="full-width">
<input matInput type="password" placeholder="Password" formControlName="password" required>
<mat-error *ngFor="let validation of account_validation_messages.password">
<mat-error class="error-message" *ngIf="accountDetailsForm.get('matching_passwords').get('password').hasError(validation.type) && (accountDetailsForm.get('matching_passwords').get('password').dirty || accountDetailsForm.get('matching_passwords').get('password').touched)">{{validation.message}}</mat-error>
</mat-error>
</mat-form-field>
<mat-form-field class="full-width">
<input matInput type="password" placeholder="Confirm Password" formControlName="confirm_password" [errorStateMatcher]="parentErrorStateMatcher" required>
<mat-error *ngFor="let validation of account_validation_messages.confirm_password">
<mat-error class="error-message" *ngIf="(accountDetailsForm.get('matching_passwords').get('confirm_password').hasError(validation.type)|| accountDetailsForm.get('matching_passwords').hasError(validation.type)) && (accountDetailsForm.get('matching_passwords').get('confirm_password').dirty || accountDetailsForm.get('matching_passwords').get('confirm_password').touched)">{{validation.message}}</mat-error>
</mat-error>
</mat-form-field>
</div>
<mat-checkbox formControlName="terms">
I accept terms and conditions
</mat-checkbox>
<mat-error *ngFor="let validation of account_validation_messages.terms">
<mat-error class="error-message" *ngIf="accountDetailsForm.get('terms').hasError(validation.type) && (accountDetailsForm.get('terms').dirty || accountDetailsForm.get('terms').touched)">{{validation.message}}</mat-error>
</mat-error>
<button class="submit-btn" color="primary" mat-raised-button type="submit" [disabled]="!accountDetailsForm.valid">
Submit
</button>
</form>
我的.ts文件代码
在这里，我为错误指定错误消息
account_validation_messages = {
'username': [
{ type: 'required', message: 'Username is required' },
{ type: 'minlength', message: 'Username must be at least 5 characters long' },
{ type: 'maxlength', message: 'Username cannot be more than 25 characters long' },
{ type: 'pattern', message: 'Your username must contain only numbers and letters' },
{ type: 'validUsername', message: 'Your username has already been taken' }
],
'email': [
{ type: 'required', message: 'Email is required' },
{ type: 'pattern', message: 'Enter a valid email' }
],
'confirm_password': [
{ type: 'required', message: 'Confirm password is required' },
{ type: 'areEqual', message: 'Password mismatch' }
],
'password': [
{ type: 'required', message: 'Password is required' },
{ type: 'minlength', message: 'Password must be at least 5 characters long' },
{ type: 'pattern', message: 'Your password must contain at least one uppercase, one lowercase, and one number' }
],
'terms': [
{ type: 'pattern', message: 'You must accept terms and conditions' }
]
}
表单验证者
this.accountDetailsForm = this.fb.group({
username: new FormControl('', Validators.compose([
UsernameValidator.validUsername,
Validators.maxLength(25),
Validators.minLength(5),
Validators.pattern('^(?=.*[a-zA-Z])(?=.*[0-9])[a-zA-Z0-9]+$'),
Validators.required
])),
email: new FormControl('', Validators.compose([
Validators.required,
Validators.pattern('^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+.[a-zA-Z0-9-.]+$')
])),
matching_passwords: this.matching_passwords_group,
terms: new FormControl(false, Validators.pattern('true'))
})
一切正常，但问题是我正在使用ngFor来显示错误，但我想在mat-error的帮助下一次显示一个错误。
答案 0 :(得分：0)
您可以在ts文件中使用for循环来找出错误。
map2删除此HTML代码，然后
In your .ts File
for (let c in this.account_validation_messages.controls) {
this.account_validation_messages.controls[c].markAsTouched();
}
答案 1 :(得分：0)
请参考DEMO PROJECT，以便更好地理解。
control-message.component.ts：
import { OnInit } from '@angular/core';
import { Component, Input } from '@angular/core';
import { FormGroup, FormControl, AbstractControl } from '@angular/forms';
import { CustomValidationService } from '../custom-validation.service'
@Component({
selector: 'app-control-message',
templateUrl: './control-message.component.html',
styleUrls: ['./control-message.component.css']
})
export class ControlMessageComponent implements OnInit {
ngOnInit() {
}
@Input() control: FormControl;
constructor() { }
/**
* This method is use to return validation errors
*/
get errorMessage() {
for (let propertyName in this.control.errors) {
if (this.control.errors.hasOwnProperty(propertyName) && this.control.touched) {
return CustomValidationService.getValidatorErrorMessage(this.getName(this.control), propertyName, this.control.errors[propertyName]);
}
if (this.control.valueChanges) {
return CustomValidationService.showValidatorErrorMessage(propertyName, this.control.errors[propertyName])
}
}
return null;
}
/**
* This method used to find the control name
* @param control - AbstractControl
*/
private getName(control: AbstractControl): string | null {
let group = <FormGroup>control.parent;
if (!group) {
return null;
}
let name: string;
Object.keys(group.controls).forEach(key => {
let childControl = group.get(key);
if (childControl !== control) {
return;
}
name = key;
});
return name;
}
}
control-message.component.html：
<mat-error *ngIf="errorMessage !== null">
{{errorMessage}}
</mat-error>
application-form.html：
<h1>Common Error Message with Custom Validation Reactive Form</h1>
<form [formGroup]="accountDetailsForm" novalidate (ngSubmit)="onSubmitAccountDetails(accountDetailsForm.value)">
<div>
<mat-form-field class="full-width">
<input matInput maxlength="25" placeholder="Username" formControlName="username" required>
</mat-form-field>
<app-control-message [control]="accountDetailsForm.controls.username"></app-control-message>
</div>
<div>
<mat-form-field class="full-width">
<input matInput type="email" placeholder="Email" formControlName="email" required>
</mat-form-field>
<app-control-message [control]="accountDetailsForm.controls.email"></app-control-message>
</div>
<div>
<mat-form-field class="full-width">
<input matInput type="password" placeholder="Password" formControlName="password" required>
</mat-form-field>
<app-control-message [control]="accountDetailsForm.controls.password"></app-control-message>
</div>
<div>
<mat-form-field>
<input matInput type="password" placeholder="Confirm Password" formControlName="confirm_password" required>
</mat-form-field>
<app-control-message [control]="accountDetailsForm.controls.confirm_password"></app-control-message>
<mat-error *ngIf="accountDetailsForm.controls.password.value != accountDetailsForm.controls.confirm_password.value">
Password & Confrm Password Did not matched.
</mat-error>
</div>
<button class="submit-btn" color="primary" mat-raised-button type="submit" [disabled]="!accountDetailsForm.valid || (accountDetailsForm.controls.confirm_password != accountDetailsForm.controls.password)">
Submit</button>
</form>
application-form.component.ts：
accountDetailsForm: FormGroup;
constructor(private fb: FormBuilder) {
}
ngOnInit() {
this.createForm()
}
onSubmitAccountDetails(val) {
console.log(val);
}
createForm() {
this.accountDetailsForm = this.fb.group({
username: ['', [
Validators.maxLength(25),
Validators.minLength(5),
Validators.pattern('^(?=.*[a-zA-Z])(?=.*[0-9])[a-zA-Z0-9]+$'),
Validators.required
]],
email: [null, [
Validators.required,
Validators.pattern('^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+.[a-zA-Z0-9-.]+$')
]],
password: [null, Validators.required],
confirm_password: [null, Validators.required]
})
}
答案 2 :(得分：0)
首先隐藏所有错误
mat-error {
display: none;
}
然后仅显示每个表单字段的第一个错误：
mat-form-field mat-error:first-child {
display: block;
}
或者仅是表格的第一个错误
form mat-error:first-child {
display: block;
}