反应表单 - 将字段标记为已触及

问题描述 投票:38回答:15

我无法找到如何将所有表单的字段标记为触摸。主要问题是,如果我不触摸字段并尝试提交表单 - 验证错误未显示。我的控制器中有一段代码占位符。 我的想法很简单:

  1. 用户点击提交按钮
  2. 所有字段标记为触及
  3. 错误格式化程序重新运行并显示验证错误

如果有人知道如何在提交时显示错误,而不实施新方法 - 请分享。谢谢!


我的简化形式:

<form class="form-horizontal" [formGroup]="form" (ngSubmit)="onSubmit(form.value)">
  <input type="text" id="title" class="form-control" formControlName="title">
  <span class="help-block" *ngIf="formErrors.title">{{ formErrors.title }}</span>
  <button>Submit</button>
</form>

而我的控制器:

import {Component, OnInit} from '@angular/core';
import {FormGroup, FormBuilder, Validators} from '@angular/forms';

@Component({
  selector   : 'pastebin-root',
  templateUrl: './app.component.html',
  styleUrls  : ['./app.component.css']
})
export class AppComponent implements OnInit {
  form: FormGroup;
  formErrors = {
    'title': ''
  };
  validationMessages = {
    'title': {
      'required': 'Title is required.'
    }
  };

  constructor(private fb: FormBuilder) {
  }

  ngOnInit(): void {
    this.buildForm();
  }

  onSubmit(form: any): void {
    // somehow touch all elements so onValueChanged will generate correct error messages

    this.onValueChanged();
    if (this.form.valid) {
      console.log(form);
    }
  }

  buildForm(): void {
    this.form = this.fb.group({
      'title': ['', Validators.required]
    });
    this.form.valueChanges
      .subscribe(data => this.onValueChanged(data));
  }

  onValueChanged(data?: any) {
    if (!this.form) {
      return;
    }
    const form = this.form;
    for (const field in this.formErrors) {
      if (!this.formErrors.hasOwnProperty(field)) {
        continue;
      }

      // clear previous error message (if any)
      this.formErrors[field] = '';
      const control = form.get(field);
      if (control && control.touched && !control.valid) {
        const messages = this.validationMessages[field];
        for (const key in control.errors) {
          if (!control.errors.hasOwnProperty(key)) {
            continue;
          }
          this.formErrors[field] += messages[key] + ' ';
        }
      }
    }
  }
}
angular angular2-forms angular2-formbuilder
15个回答
94
投票

以下函数通过表单组中的控件进行递归并轻轻触摸它们。因为controls字段是一个对象,所以代码在表单组的控制字段上调用Object.values()。

  /**
   * Marks all controls in a form group as touched
   * @param formGroup - The form group to touch
   */
  private markFormGroupTouched(formGroup: FormGroup) {
    (<any>Object).values(formGroup.controls).forEach(control => {
      control.markAsTouched();

      if (control.controls) {
        this.markFormGroupTouched(control);
      }
    });
  }

1
投票

这是我实际使用的代码。

validateAllFormFields(formGroup: any) {
    // This code also works in IE 11
    Object.keys(formGroup.controls).forEach(field => {
        const control = formGroup.get(field);

        if (control instanceof FormControl) {
            control.markAsTouched({ onlySelf: true });
        } else if (control instanceof FormGroup) {               
            this.validateAllFormFields(control);
        } else if (control instanceof FormArray) {  
            this.validateAllFormFields(control);
        }
    });
}    

1
投票

这段代码适合我:

markAsRequired(formGroup: FormGroup) {
  if (Reflect.getOwnPropertyDescriptor(formGroup, 'controls')) {
    (<any>Object).values(formGroup.controls).forEach(control => {
      if (control instanceof FormGroup) {
        // FormGroup
        markAsRequired(control);
      }
      // FormControl
      control.markAsTouched();
    });
  }
}

1
投票

A solution without recursion

对于那些担心性能的人,我提出了一个不使用递归的解决方案,尽管它仍然遍历所有级别的所有控件。

 /**
  * Iterates over a FormGroup or FormArray and mark all controls as
  * touched, including its children.
  *
  * @param {(FormGroup | FormArray)} rootControl - Root form
  * group or form array
  * @param {boolean} [visitChildren=true] - Specify whether it should
  * iterate over nested controls
  */
  public markControlsAsTouched(rootControl: FormGroup | FormArray,
    visitChildren: boolean = true) {

    let stack: (FormGroup | FormArray)[] = [];

    // Stack the root FormGroup or FormArray
    if (rootControl &&
      (rootControl instanceof FormGroup || rootControl instanceof FormArray)) {
      stack.push(rootControl);
    }

    while (stack.length > 0) {
      let currentControl = stack.pop();
      (<any>Object).values(currentControl.controls).forEach((control) => {
        // If there are nested forms or formArrays, stack them to visit later
        if (visitChildren &&
            (control instanceof FormGroup || control instanceof FormArray)
           ) {
           stack.push(control);
        } else {
           control.markAsTouched();
        }
      });
    }
  }

此解决方案适用于FormGroup和FormArray。

你可以在这里玩它:angular-mark-as-touched


1
投票

从Angular v8开始,您可以在markAllAsTouched方法的帮助下使用此内置功能。

举个例子,你可以像使用它一样

form.markAllAsTouched();

请参阅官方文档:https://angular.io/api/forms/AbstractControl#markallastouched


0
投票

我完全理解OP的挫败感。我使用以下内容:

实用功能:

/**
 * Determines if the given form is valid by touching its controls 
 * and updating their validity.
 * @param formGroup the container of the controls to be checked
 * @returns {boolean} whether or not the form was invalid.
 */
export function formValid(formGroup: FormGroup): boolean {
  return !Object.keys(formGroup.controls)
    .map(controlName => formGroup.controls[controlName])
    .filter(control => {
      control.markAsTouched();
      control.updateValueAndValidity();
      return !control.valid;
    }).length;
}

用法:

onSubmit() {
  if (!formValid(this.formGroup)) {
    return;
  }
  // ... TODO: logic if form is valid.
}

请注意,此功能尚不适合嵌套控件。


0
投票

this gem。到目前为止,我见过最优雅的解决方案。

完整代码

import { Injectable } from '@angular/core';
import { FormGroup } from '@angular/forms';

const TOUCHED = 'markAsTouched';
const UNTOUCHED = 'markAsUntouched';
const DIRTY = 'markAsDirty';
const PENDING = 'markAsPending';
const PRISTINE = 'markAsPristine';

const FORM_CONTROL_STATES: Array<string> = [TOUCHED, UNTOUCHED, DIRTY, PENDING, PRISTINE];

@Injectable({
  providedIn: 'root'
})
export class FormStateService {

  markAs (form: FormGroup, state: string): FormGroup {
    if (FORM_CONTROL_STATES.indexOf(state) === -1) {
      return form;
    }

    const controls: Array<string> = Object.keys(form.controls);

    for (const control of controls) {
      form.controls[control][state]();
    }

    return form;
  }

  markAsTouched (form: FormGroup): FormGroup {
    return this.markAs(form, TOUCHED);
  }

  markAsUntouched (form: FormGroup): FormGroup {
    return this.markAs(form, UNTOUCHED);
  }

  markAsDirty (form: FormGroup): FormGroup {
    return this.markAs(form, DIRTY);
  }

  markAsPending (form: FormGroup): FormGroup {
    return this.markAs(form, PENDING);
  }

  markAsPristine (form: FormGroup): FormGroup {
    return this.markAs(form, PRISTINE);
  }
}

-1
投票
    /**
    * Marks as a touched
    * @param { FormGroup } formGroup
    *
    * @return {void}
    */
    markFormGroupTouched(formGroup: FormGroup) {
        Object.values(formGroup.controls).forEach((control: any) => {

            if (control instanceof FormControl) {
                control.markAsTouched();
                control.updateValueAndValidity();

            } else if (control instanceof FormGroup) {
                this.markFormGroupTouched(control);
            }
        });
    }

9
投票

关于@masterwork的答案。我尝试了这个解决方案,但是当函数试图在FormGroup中递归地挖掘时我得到了一个错误,因为在这一行传递了一个FormControl参数,而不是FormGroup:

control.controls.forEach(c => this.markFormGroupTouched(c));

这是我的解决方案

markFormGroupTouched(formGroup: FormGroup) {
 (<any>Object).values(formGroup.controls).forEach(control => {
   if (control.controls) { // control is a FormGroup
     markFormGroupTouched(control);
   } else { // control is a FormControl
     control.markAsTouched();
   }
 });
}

8
投票

在Angular 8+中你可以简单地使用

this.form.markAllAsTouched();

将控件及其后代控件标记为触摸。


6
投票

循环使用表单控件并将其标记为已触摸也可以:

for(let i in this.form.controls)
    this.form.controls[i].markAsTouched();

3
投票

这是我的解决方案

      static markFormGroupTouched (FormControls: { [key: string]: AbstractControl } | AbstractControl[]): void {
        const markFormGroupTouchedRecursive = (controls: { [key: string]: AbstractControl } | AbstractControl[]): void => {
          _.forOwn(controls, (c, controlKey) => {
            if (c instanceof FormGroup || c instanceof FormArray) {
              markFormGroupTouchedRecursive(c.controls);
            } else {
              c.markAsTouched();
            }
          });
        };
        markFormGroupTouchedRecursive(FormControls);
      }

2
投票

我有这个问题,但发现这样做的“正确”方式,尽管它没有在我找到过的任何Angular教程中。

在您的HTML中,在form标记上,添加模板驱动的表单示例使用的相同模板引用变量#myVariable='ngForm'('hashtag'变量),以及Reactive Forms示例使用的内容:

<form [formGroup]="myFormGroup" #myForm="ngForm" (ngSubmit)="submit()">

现在您可以在模板中访问myForm.submitted,您可以使用myFormGroup.controls.X.touched代替(或除此之外):

<div *ngIf="myForm.submitted" class="text-error"> <span *ngIf="myFormGroup.controls.myFieldX.errors?.badDate">invalid date format</span> <span *ngIf="myFormGroup.controls.myFieldX.errors?.isPastDate">date cannot be in the past.</span> </div>

知道myForm.form === myFormGroup是真的......只要你不忘记="ngForm"部分。如果单独使用#myForm,它将无法工作,因为var将设置为HtmlElement而不是驱动该元素的Directive。

根据Reactive Forms教程,知道myFormGroup在Component的typescript代码中可见,但myForm不是,除非你通过方法调用传递它,如submit(myForm)submit(myForm: NgForm): void {...}。 (注意NgForm在打字稿中是标题大写,但在HTML中是驼峰大小写。)


1
投票
onSubmit(form: any): void {
  if (!this.form) {
    this.form.markAsTouched();
    // this.form.markAsDirty(); <-- this can be useful 
  }
}

1
投票

我就是这样做的。在按下提交按钮(或触摸表单)之前,我不希望显示错误字段。

import {FormBuilder, FormGroup, Validators} from "@angular/forms";

import {OnInit} from "@angular/core";

export class MyFormComponent implements OnInit {
  doValidation = false;
  form: FormGroup;


  constructor(fb: FormBuilder) {
    this.form = fb.group({
      title: ["", Validators.required]
    });

  }

  ngOnInit() {

  }
  clickSubmitForm() {
    this.doValidation = true;
    if (this.form.valid) {
      console.log(this.form.value);
    };
  }
}

<form class="form-horizontal" [formGroup]="form" >
  <input type="text" class="form-control" formControlName="title">
  <div *ngIf="form.get('title').hasError('required') && doValidation" class="alert alert-danger">
            title is required
        </div>
  <button (click)="clickSubmitForm()">Submit</button>
</form>

1
投票

我遇到了同样的问题,但我不想用处理这个的代码“污染”我的组件。特别是因为我需要多种形式,我不想在各种场合重复这些代码。

因此我创建了一个指令(使用到目前为止发布的答案)。该指令装饰NgForm的onSubmit-Method:如果表单无效,则将所有字段标记为已触摸并中止提交。否则通常的onSubmit-Method正常执行。

import {Directive, Host} from '@angular/core';
import {NgForm} from '@angular/forms';

@Directive({
    selector: '[appValidateOnSubmit]'
})
export class ValidateOnSubmitDirective {

    constructor(@Host() form: NgForm) {
        const oldSubmit = form.onSubmit;

        form.onSubmit = function (): boolean {
            if (form.invalid) {
                const controls = form.controls;
                Object.keys(controls).forEach(controlName => controls[controlName].markAsTouched());
                return false;
            }
            return oldSubmit.apply(form, arguments);
        };
    }
}

用法:

<form (ngSubmit)="submit()" appValidateOnSubmit>
    <!-- ... form controls ... -->
</form>
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