仅在提交或用户输入时验证表单字段 [英] Validate form field only on submit or user input

问题描述

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.

我该如何实施?

解决方案

使用 $dirty 标志仅在用户与输入交互后才显示错误:

<input type="email" name="email" ng-model="user.email" required/><span ng-show="form.email.$dirty && form.email.$error.required">电子邮件是必需的</span>

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:

<div><input type="email" name="email" ng-model="user.email" required/><span ng-show="(form.email.$dirty || 已提交) && form.email.$error.required">电子邮件是必需的</span>

<div><button type="submit">提交</button>

</表单>

function MyCtrl($scope){$scope.submit = function(){//将已提交"标志设置为真$scope.submitted = true;//将表单发送到服务器//$http.post ...}};

然后，如果 ng-showexpression 中的所有 JS 对您来说看起来太多了，您可以将其抽象为一个单独的方法:

function MyCtrl($scope){$scope.submit = function(){//将已提交"标志设置为真$scope.submitted = true;//将表单发送到服务器//$http.post ...}$scope.hasError = 函数(字段，验证){如果(验证){return ($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);};};

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

<div><button type="submit">提交</button>

</表单>

I have form fields that are validated using required. The problem is, that the error is displayed immediately when the form is rendered. I want it only to be displayed after the user actually typed in the text field, or on submit.

How can I implement this?

解决方案

Use $dirty flag to show the error only after user interacted with the input:

<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>

If you want to trigger the errors only after the user has submitted the form than you may use a separate flag variable as in:

<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 ...
  } 
};

Then, if all that JS inside ng-showexpression looks too much for you, you can abstract it into a separate method:

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>

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