Angular2：找出FormControl是否需要验证器？ [英] Angular2: Find out if FormControl has required validator?

问题描述

 这个是否有人知道如何找出Angular2 FormControl的方法.form = builder.group（{name：[''，Validators.required]}; 
  

Can然后我查询 this.form.controls ['name'] 控件是否为必填字段？我知道我可以检查它是否有效，但这不是我希望。

亲切的问候，
Marc

解决方案

这个函数应该适用于FormGroups和FormControls。
$ b $ pre $ export const hasRequiredField =（abstractControl：AbstractControl）：boolean => {$ b $如果（abstractControl.validator）{
const validator = abstractControl.validator（{} as AbstractControl）;
if（validator&& validator.required）{
return true;


if（abstract control ['controls']）{
for（const controlName （abstractControl ['controls']）{
if（abstractControl ['controls'] [controlName]）{
if（hasRequiredField（abstractControl ['controls'] [controlName]））{
返回true;
}
}
}
}
return false;
};


does someone know a way to find out for an Angular2 FormControl if the required validor is registered for the control.

this.form = builder.group({name: ['', Validators.required]};

Can I then query the this.form.controls['name'] control if it is a required field? I know I can check if it is valid, but that's not what I want.

Kind regards, Marc

解决方案

This function should work for FormGroups and FormControls

  export const hasRequiredField = (abstractControl: AbstractControl): boolean => {
    if (abstractControl.validator) {
        const validator = abstractControl.validator({}as AbstractControl);
        if (validator && validator.required) {
            return true;
        }
    }
    if (abstractControl['controls']) {
        for (const controlName in abstractControl['controls']) {
            if (abstractControl['controls'][controlName]) {
                if (hasRequiredField(abstractControl['controls'][controlName])) {
                    return true;
                }
            }
        }
    }
    return false;
};

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