如何在 angularjs 中使用模板设置字段名 [英] how to set the fieldname using a template in angularjs

问题描述

我希望字段的标签与字段验证属性进行一些交互.我创建了一个工作示例的 plunker.

I want to have some interaction of the label for a field with the field validation properties. I created a plunker of a working example.

http://plnkr.co/edit/oNq5lmjtjRDaEkzKsrR2?p=preview

但在这个例子中，字段名是硬编码的.

But in this example the fieldname is hardcoded.

我尝试通过范围变量将字段名设置到模板中.这不起作用:

I tryed to set the fieldname via scope variable into the template. This is not working:

http://plnkr.co/edit/yEl04xyFR5RWYCmI2bMH?p=preview

HTML:

<form name="myForm" ng-controller="ctrl">
  <fieldset field-name="{{model.fieldName}}" label-text="{{model.label}}" ng-model="model.value">
  <fieldset>
</form>

JavaScript:

JavaScript:

var app = angular.module('myApp',[]);
app.directive('fieldset', function(){
  return {
    template: '<label ng-class="{invalid:$parent.myForm[{{fieldName}}].$invalid}">{{lbl}}</label>: ' +
              '<input name="{{fieldName}}" ng-model="value" required>',
    restrict : 'E',
    scope : {
              value : '=ngModel',
              lbl : '@labelText',
              fieldName : '@'
            },

    link : function(scope, elem, attrs) {
      console.log(scope.$parent.myForm);
    }        
  }
})

app.controller('ctrl', function($scope) {
  $scope.model = {
    fieldName : 'myField',
    label : 'Label for Field',
    value : 6
  } 
});

scope.$parent.myForm 中的字段名是{{fieldName}}"而不是myField".但在 DOM 中，字段名按预期分配.我该如何解决这个问题?

The fieldname in scope.$parent.myForm is '{{fieldName}}' instead of 'myField'. But in DOM the fieldname is assigned as expected. How can I solve this problem?

推荐答案

Stewie 是绝对正确的.如果创建了 ng-model 指令，它将立即在表单中注册.如果您查看 angular 源，您会发现 ngModel 是按其当前名称在数组 form 中注册的:

Stewie is absolutely right. If the ng-model directive is created it will immediately be registered at the form. If you have a look at the angular sources you will find that the ngModels are registered by their current name in the array form:

if (control.$name) {
  form[control.$name] = control;
}

就您而言，这是{{fieldName}}".这个name 不能改变，因为它是数组中的键.那么我们可以做些什么来改变这种情况呢?如果我们看一下 FormController API 我们可以看到有删除 ($removeControl) 或添加 ($addControl) 控件的函数.这两个函数都需要 NgModelController 作为输入参数.例如.angular 为我们的输入元素创建的 NgModelController.我们可以通过以下方式访问此控制器:

In your case this is '{{fieldName}}'. This name can not be changed, because it is the key in the array. So what can we do to change this? If we have a look at the FormController API we can see there are functions to remove ($removeControl) or add ($addControl) controls. Both functions require the NgModelController as input parameter. E.g. the NgModelController that angular has created for our input element. We have access to this controller by:

var modelController = inputElement.controller('ngModel');

var modelController = inputElement.controller('ngModel');

我认为我们现在拥有了编写指令的所有信息:

I think we have now all information together to write the directive:

app.directive('fieldset', function(){
  return {
    template: '<label ng-class="{invalid:form[fieldName].$invalid}">{{lbl}}</label>: ' +
              '<input name="{{fieldName}}" ng-model="value" required>',
    restrict : 'E',
    require: '^form', // we need the parent NgFormController 
    scope : {
              value : '=ngModel',
              lbl : '@labelText',
              fieldName : '@'
         },

    link : function(scope, elem, attrs, formCtrl) {
       // get the NgModelController for the input element
       var modelCtrl = elem.find('input').controller('ngModel');

       // remove the ModelController from the FormController
       formCtrl.$removeControl(modelCtrl); 
       // set the right name
       modelCtrl.$name = scope.fieldName; 
       // add the namend ModelController to the FormController
       formCtrl.$addControl(modelCtrl); 

       // publish the FormController to the scope - so we don't need to mess around with the parent scope.
       scope.form = formCtrl;
    }
  }
})

我还建议将 NgFormController 发布到指令范围.所以你可以写你的css条件:

I would also suggest publish the NgFormController to the directives scope. So you may write your css condition:

form[fieldName].$invalid

代替:

$parent.myForm[fieldName].$invalid

它更通用，因为您不需要知道表单的名称.

It is more generic, because you don't need to know the name of your form.

PLUNKR

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