Question

我有使用required验证的表单字段。问题是，在呈现表单时会立即显示错误。我希望它仅在用户实际输入文本字段或提交后显示。

我该如何实现？

Answer 1

仅在用户与输入交互后才使用$dirty标志显示错误：

<div>
  <input type="email" name="email" ng-model="user.email" required />
  <span ng-show="form.email.$dirty && form.email.$error.required">Email is required</span>
</div>

如果您只想在用户提交表单后触发错误，则可以使用单独的标志变量，如下所示：

<form ng-submit="submit()" name="form" ng-controller="MyCtrl">
  <div>
    <input type="email" name="email" ng-model="user.email" required />
    <span ng-show="(form.email.$dirty || submitted) && form.email.$error.required">
      Email is required
    </span>
  </div>

  <div>
    <button type="submit">Submit</button>
  </div>
</form>

function MyCtrl($scope){
  $scope.submit = function(){
    // Set the 'submitted' flag to true
    $scope.submitted = true;
    // Send the form to server
    // $http.post ...
  } 
};

然后，如果ng-show表达式中的所有JS对你来说太过分了，你可以将它抽象为一个单独的方法：

function MyCtrl($scope){
  $scope.submit = function(){
    // Set the 'submitted' flag to true
    $scope.submitted = true;
    // Send the form to server
    // $http.post ...
  }

  $scope.hasError = function(field, validation){
    if(validation){
      return ($scope.form[field].$dirty && $scope.form[field].$error[validation]) || ($scope.submitted && $scope.form[field].$error[validation]);
    }
    return ($scope.form[field].$dirty && $scope.form[field].$invalid) || ($scope.submitted && $scope.form[field].$invalid);
  };

};

<form ng-submit="submit()" name="form">
  <div>
    <input type="email" name="email" ng-model="user.email" required />
    <span ng-show="hasError('email', 'required')">required</span>
  </div>

  <div>
    <button type="submit">Submit</button>
  </div>
</form>

Answer 2

如果要在表单提交时显示错误消息，可以使用条件form.$submitted检查是否尝试提交表单。请查看以下示例。

<form name="myForm" novalidate ng-submit="myForm.$valid && createUser()">
  <input type="text" name="name" ng-model="user.name" placeholder="Enter name of user" required>
  <div ng-messages="myForm.name.$error" ng-if="myForm.$submitted">
    <div ng-message="required">Please enter user name.</div>
  </div>

  <input type="text" name="address" ng-model="user.address" placeholder="Enter Address" required ng-maxlength="30">
  <div ng-messages="myForm.name.$error" ng-if="myForm.$submitted">
    <div ng-message="required">Please enter user address.</div>
    <div ng-message="maxlength">Should be less than 30 chars</div>
  </div>

  <button type="submit">
    Create user
  </button>
</form>

Answer 3

您可以使用angularjs表单状态form.$submitted。最初form.$submitted值为false，成功提交表单后将成为true。

Answer 4

Erik Aigner，

请使用$ dirty（字段已被修改）和$ invalid（字段内容无效）。

请查看下面的角度表单验证示例

1）

用户输入输入的验证示例HTML：

<form  ng-app="myApp"  ng-controller="validateCtrl" name="myForm" novalidate>
  <p>Email:<br>
    <input type="email" name="email" ng-model="email" required>
    <span ng-show="myForm.email.$dirty && myForm.email.$invalid">
      <span ng-show="myForm.email.$error.required">Email is required.</span>
      <span ng-show="myForm.email.$error.email">Invalid email address.</span>
      </span>
  </p>
    </form>

2）

用户提交的验证示例HTML / Js：

      <form  ng-app="myApp"  ng-controller="validateCtrl" name="myForm" novalidate form-submit-validation="">
      <p>Email:<br>
        <input type="email" name="email" ng-model="email" required>
        <span ng-show="submitted || myForm.email.$dirty && myForm.email.$invalid">
          <span ng-show="myForm.email.$error.required">Email is required.</span>
          <span ng-show="myForm.email.$error.email">Invalid email address.</span>
          </span>
      </p>
<p>
  <input type="submit">
</p>
</form>

自定义指令：

app.directive('formSubmitValidation', function () {

        return {
            require: 'form',
            compile: function (tElem, tAttr) {

                tElem.data('augmented', true);

                return function (scope, elem, attr, form) {
                    elem.on('submit', function ($event) {
                        scope.$broadcast('form:submit', form);

                        if (!form.$valid) {
                            $event.preventDefault();
                        }
                        scope.$apply(function () {
                            scope.submitted = true;
                        });


                    });
                }
            }
        };


  })

3）

您不希望使用指令使用ng-change函数，如下所示

  <form  ng-app="myApp"  ng-controller="validateCtrl" name="myForm" novalidate ng-change="submitFun()">
      <p>Email:<br>
        <input type="email" name="email" ng-model="email" required>
        <span ng-show="submitted || myForm.email.$dirty && myForm.email.$invalid">
          <span ng-show="myForm.email.$error.required">Email is required.</span>
          <span ng-show="myForm.email.$error.email">Invalid email address.</span>
          </span>
      </p>
<p>
  <input type="submit">
</p>
</form>

Controller SubmitFun（）JS：

 var app = angular.module('example', []);
 app.controller('exampleCntl', function($scope) {
 $scope.submitFun = function($event) {
 $scope.submitted = true;
  if (!$scope.myForm.$valid) 
  {
        $event.preventDefault();
   }
  }

}）;

Answer 5

可以通过触发此元素上的change事件来处理对表单元素的调用：

a）例如：以形式

触发对分离元素的更改

$scope.formName.elementName.$$element.change();

b）例如：触发每个表单元素的更改事件，例如ng-submit，ng-click，ng-blur ...

vm.triggerChangeForFormElements = function() {
    // trigger change event for each of form elements
    angular.forEach($scope.formName, function (element, name) {
        if (!name.startsWith('$')) {
            element.$$element.change();
        }
    });
};

c）和另一种方式

    var handdleChange = function(form){
        var formFields = angular.element(form)[0].$$controls;
        angular.forEach(formFields, function(field){
            field.$$element.change();
        });
    };

仅在提交或用户输入时验证表单字段

5 个答案: