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[英]prevent form submission if validation failed after iterating over each form element with jquery's .each() function
[英]Angular form validation , access form control while iterating over it on HTML
我有一个问题列表,其答案选项为单选按钮字段。 我从JSON文件中得到这些问题和答案。所以我在HTML上迭代它并动态地为formControlName赋值。 我的问题是如何在迭代控制值时进行验证?
*ngIf="cricketForm.control.get('ques{{i}}').invalid"
*ngIf="cricketForm.control.get('ques{{i}}').invalid"
这给了我一个错误。 如何以正确的方式做到这一点?
https://stackblitz.com/edit/angular-yq4lyz-zt9b3h?file=app/form-field-overview-example.html目前验证工作不正常
html文件:
<form [formGroup]="cricketForm">
<div *ngFor = "let user of userJson; let i =index ">
<div class="label1" for="NameId">{{user.question}}</div>
<mat-radio-group formControlName="ques{{i+1}}" aria-label="Select an option">
<div *ngFor = "let option of user.options; let j =index">
<mat-radio-button [value]=j>{{option}}</mat-radio-button>
</div>
</mat-radio-group>
<div class="invalid-feedback" *ngIf="cricketForm.control.get('ques{{i}}').invalid" >This field is required</div>
</div>
<button (click)="onSubmit()">Submit</button>
<button (click)="onReset()">Reset</button>
</form>
ts文件:
ngOnInit() {
this.cricketForm = this.formBuilder.group({
ques1: [null, [Validators.required]],
ques2: [null, [Validators.required]],
ques3: [null, [Validators.required]],
ques4: [null, [Validators.required]]
})
this.userDataService.getJSON().subscribe(data => {
console.log(data);
this.userJson = data;
this.options = data.options
});
}
示例JSON数据:
[
{"question": "Who Was The First Indian To Hit A Test Century?", "options":["Lala Amarnath","Kapil Dev", "Sunil Gavaskar"],"ans":"Lala Amarnath"},
{"question":"Who Won The Inaugural Asia Cup Championship?","options":["Pakistan","Sri Lanka", "India"],"ans":"India"},
{"question":"Who Was Australia’s First Captain?","options":["F.S.Jackson"
,"D.W. Gregory", "Tony Lewis"],"ans":"D.W. Gregory"},
{"question":" When And Where Was The First Ranji Trophy Match Played?","options":["kolkata"
,"Mumbai", "Chennai"],"ans":"Chennai"}
]
您有语法错误。 一定是
*ngIf="cricketForm.get('ques'+(i+1)).invalid"
看看你的分叉stackblitz
注意:我认为您必须尝试使用FormArrays重新思考您的代码。 方式很简单
<form formGroup="formArray">
<div *ngFor = "let control of formArray.controls; let i =index ">
<div class="label1" for="NameId">{{userJson[i].question}}</div>
<mat-radio-group [formControl]="control" aria-label="Select an option">
<div *ngFor = "let option of userJson[i].options; let j =index">
<mat-radio-button [value]=j>{{option}}</mat-radio-button>
</div>
</mat-radio-group>
<div class="invalid-feedback" *ngIf="control.invalid" >This field is required</div>
</div>
<button (click)="onSubmit()">Submit</button>
<button (click)="onReset()">Reset</button>
</form>
看到这一点,我们遍历formArray.controls并使用i = index。 要显示标签,请使用userJson [i]
哪里:
this.formArray=new FormArray(
this.userJson.map(
()=>new FormControl(null,Validators.required))
);
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