如何在angular2中验证FormArray的长度 [英] How to Validate FormArray length in angular2

问题描述

我有如下所示的angular2数据驱动形式

I have a data driven form in angular2 like below

this.formBuilder.group({
  'name': ['',Validators.required],
  'description': ['', Validators.required],
  'places': this.formBuilder.array([], Validators.minlength(1)) 
})

我想向place formArray添加验证，所以我要添加minlength验证，但是最小长度验证不适用于formArray.

I want to add validations to the place formArray, so i am adding minlength validation, but minlength validation is not working on formArray.

formArray的其他验证方式是什么，因此仅当place数组包含至少一个地方时，该表单才必须有效.

What are the other validations for formArray, so that form must be valid only when places array contain atleast one place.

推荐答案

Validators.required为您做魔术:

this.formGroup = this.formBuilder.group({
    taskTreeId: [Common.UID()],
    executionProgrammedTime: ["", [Validators.required]],
    description: [""],
    tasks: this.formBuilder.array([], Validators.required)
});

<button type="button" class="btn btn-success btn-rounded" 
    [disabled]="!formGroup.valid">SAVE</button>

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