Angular 5 动态表单中的自定义验证器

Question

我正在从 Angular 5 中的可配置 json 创建一个动态表单。一切正常，但我无法为特定字段添加自定义验证器。我收到类似

的错误

TypeError: v is not a function

Json

{
      "key": "age",
      "label": "Age",
      "required": false,
      "order": 4,
      "controlType": "textbox",
      "validations": ['required', 'minlength'],
      "custom":['rangeValidator'],//custom validator function name
      "type": "email"
    }

制作动态表单控件的组件：

toFormGroup(questions) {
    let group: any = {};
    questions.forEach(question => {
      group[question.key] = new FormControl(question.value || '', this.getValidators(question)
      );
    });
    return new FormGroup(group);
  }

  getValidators(question) {
    let vals = [];
    question.validations.forEach((v) => {
      if (v == 'required') {
        vals.push(Validators.required);
      }
      if (v == 'minlength') {
        vals.push(Validators.minLength(4))
      }
    });
    if (question.custom || question.custom.length > 0) {
      question.custom.forEach((va) => {
        vals.push(va);
      });
    }

return vals;

}

主组件文件：

    import { Component, OnInit, Input } from '@angular/core';
   import { FormGroup, AbstractControl ,FormControl} from '@angular/forms';
function rangeValidator(c: FormControl) {
    if (c.value !== undefined && (isNaN(c.value) || c.value > 1 || c.value < 10)) {
      return { range: true };
    }
    return null;
  }
@Component({
  selector: 'app-question',
  templateUrl: './dynamic-form-question.component.html',
  styleUrls: ['./dynamic-form-question.component.css']
})
export class DynamicFormQuestionComponent implements OnInit {
  @Input() question;
  @Input() form: FormGroup;
  get isValid() { return this.form.controls[this.question.key].valid; }

  constructor() { }

  ngOnInit() {
    console.log("My form", this.form.value)

  }


}

Stackblitz Url

任何想法，请帮助

Answer 1

那里

  if (question.custom || question.custom.length > 0) {
      question.custom.forEach((va) => {
        vals.push(va);
      });
    }

您想添加自定义验证器，但实际上您只需将字符串“rangeValidator”添加到验证器数组中。所以是的 v 不是一个函数:)

您应该像这样将范围验证器声明为海关验证器的静态函数：

export class CustomValidators {
    static rangeValidator(c: FormControl) {
    if (c.value !== undefined && (isNaN(c.value) || c.value > 1 || c.value < 10)) {
      return { range: true };
    }
    return null;
  }

然后将其导入并像这样使用它：

 getValidators(question) {
    ....

    if (question.custom || question.custom.length > 0) {
      question.custom.forEach((va) => {
        vals.push(CustomValidators[va]);
      });
    }

    return vals;
  }

见forked stackblitz

注意：这个分叉只解决当前问题。你的全局示例表单验证仍然不起作用