AngularJS：在更改/键入/立即显示表单输入错误

Question

如果您在下面的示例中删除了输入元素中的初始文本，那么在模糊该元素之前它不会显示错误。

我想让输入元素的下划线变成红色，并在您删除输入中的最后一个字符时立即显示错误。

有人有什么想法吗？

var app = angular.module('myApp', ['ngMaterial', 'ngMessages']);

app.controller('DemoCtrl', function() {
  this.name = 'test text';
});

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>Angular JS</title>
  <link
    rel="stylesheet"
    href="https://ajax.googleapis.com/ajax/libs/angular_material/1.1.6/angular-material.min.css">
</head>
<body ng-app="myApp">
  <div ng-controller="DemoCtrl as demo">
    <form name="testForm">
      <md-input-container>
        <input
          name="testInput"
          ng-model="demo.name"
          required
          aria-label="test input"
          type="text">
        <ng-messages
          for="testForm.testInput.$error"
          role="alert">
          <ng-message when="required">
            <span>
              required
            </span>
          </ng-message>
        </ng-messages>
      </md-input-container>
    </form>
  </div>
  
  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.7/angular.min.js"></script>
  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.7/angular-animate.min.js"></script>
  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.7/angular-aria.min.js"></script>
  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.7/angular-messages.min.js"></script>
  <script src="https://ajax.googleapis.com/ajax/libs/angular_material/1.1.6/angular-material.min.js"></script>
</body>
</html>

Answer 1

实现此目的的一种方法是在您的输入中添加 ng-change="testForm.$setSubmitted()"。这将直接触发更改时的表单验证。在 ng-change 上使用 testForm.$setSubmitted() 时，您需要检查依赖函数。也许您的应用程序中的其他一些行为可能会受到影响。

<input name="testInput"
       ng-model="demo.name"
       ng-change="testForm.$setSubmitted()"
       required
       aria-label="test input"
       type="text">

示例：

var app = angular.module('myApp', ['ngMaterial', 'ngMessages']);

app.controller('DemoCtrl', function() {
  this.name = 'test text';
});

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>Angular JS</title>
  <link rel="stylesheet" href="https://ajax.googleapis.com/ajax/libs/angular_material/1.1.6/angular-material.min.css">
</head>
<body ng-app="myApp">
  <div ng-controller="DemoCtrl as demo">
    <form name="testForm">
      <md-input-container>
        <input name="testInput"
               ng-model="demo.name"
               required
               aria-label="test input"
               ng-change="testForm.$setSubmitted()"
               type="text">
        <ng-messages for="testForm.testInput.$error" role="alert">
          <ng-message when="required">
            <span>
              required
            </span>
          </ng-message>
        </ng-messages>
      </md-input-container>
    </form>
  </div>
  
  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.7/angular.min.js"></script>
  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.7/angular-animate.min.js"></script>
  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.7/angular-aria.min.js"></script>
  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.7/angular-messages.min.js"></script>
  <script src="https://ajax.googleapis.com/ajax/libs/angular_material/1.1.6/angular-material.min.js"></script>
</body>
</html>

Answer 2

这是 md-input-container 中动画触发方式的一个怪癖。 Angular Material 有一个标志，允许您在检查输入错误时更改，以最小化动画循环。默认值有点过于严格，但可以更改。

md-input-container 有一个可以添加的可选标志：md-is-error。这允许您传递一个表达式来控制何时检查输入是否有错误。

试试这个：<md-input-container md-is-error="testForm.testInput.$invalid">

var app = angular.module('myApp', ['ngMaterial', 'ngMessages']);

app.controller('DemoCtrl', function() {
  this.name = 'test text';
});

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>Angular JS</title>
  <link rel="stylesheet" href="https://ajax.googleapis.com/ajax/libs/angular_material/1.1.6/angular-material.min.css">
</head>
<body ng-app="myApp">
  <div ng-controller="DemoCtrl as demo">
    <form name="testForm">
      <md-input-container md-is-error="testForm.testInput.$invalid">
        <input name="testInput"
               ng-model="demo.name"
               required
               aria-label="test input"
               type="text">
        <ng-messages for="testForm.testInput.$error" role="alert">
          <ng-message when="required">
            <span>
              required
            </span>
          </ng-message>
        </ng-messages>
      </md-input-container>
    </form>
  </div>
  
  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.7/angular.min.js"></script>
  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.7/angular-animate.min.js"></script>
  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.7/angular-aria.min.js"></script>
  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.7/angular-messages.min.js"></script>
  <script src="https://ajax.googleapis.com/ajax/libs/angular_material/1.1.6/angular-material.min.js"></script>
</body>
</html>

AngularJS：在更改/键入/立即显示表单输入错误

AngularJS: Show form input error on change / typing / immediately

javascript

angularjs

angularjs-material

ng-messages

示例：