Guide on how to update the controller value in AngularJS directive to trigger data retrieval

Question

Guide on how to update the controller value in AngularJS directive to trigger data retrieval

I currently have multiple controllers responsible for fetching data from the server. One example of such a controller is shown below:

var vm = this;
  
  var month = 1;
  
  loadStatusCount();
  
  function loadStatusCount() {
      vm.summaryCount = [];
      
      statusCountService.setMonth(month);
      statusCountService.setType('e');
      statusCountService.getStatusCount()
                  .then(function (report) {
                      applyCount(report);
                  });
  }
  
  function applyCount(report) {
      vm.summaryCount = report[0];
  }
  
  vm.getTotal = function () {
      var total = 0;
      for (var i = 0; i < vm.summaryCount.length; i++) {
          var count = vm.summaryCount[i].count;
          total = total + count;
      }
      return total;
  }

The rest of the controllers have similar code, the only difference being the type parameter.

As of now, I have a directive that displays a template.

monthlyReportApp.directive('statusCount', function () {
      return {
          restrict: 'AE',
          replace: false,
          templateUrl: 'Scripts/app/views/templates/status-count-template.html',
          link: linker
      }
  
      function linker(scope, el, attrs, ngModel) {
          scope.title = attrs.title;
          scope.class = attrs.class;
      }
  });

I utilize this directive in my HTML like so:

<div status-count data-class="fa fa-check-square-o" data-title="Prior Auth Count" class="panel panel-default" ng-controller="PACountCtrl as ctrl">

          </div>

While it's not a pressing issue, I am interested in reducing redundancy. Hence, instead of creating multiple similar controllers, how can I have a single controller that can be utilized by the directive to fetch data with different type values for various div elements?

javascript angularjs angularjs-directive angularjs-scope angularjs-controller

Answer 1

Answer №1

To dynamically pass the attribute you want, consider using the type attribute. If you plan on using this directive multiple times, ensure that the directive has an isolated scope to increase reusability. Modify your directive to have an isolated scope for better component reusability.

Avoid assigning a controller to the DOM using ng-controller when you already have a directive in place. Remove it from the DOM and apply the controller from the directive itself. Pass the statusType through the directive's attribute so it can be accessed within the isolated scope of the directive. Use scope.statusType in your directive to access the value and adjust your code accordingly to

statusCountService.setType(scope.statusType);

.

When using the controllerAs syntax within your controller and isolating the scope, the scope is not directly bound to the this context of the controller. To address this, use the bindToController property, which employs the angular.bind API method to bind all the scope variables to the controller's this context. Angular 1.3+ offers bindToController: true, while angular 1.4+ simplifies this process by introducing the bindToController property to handle isolated scope and binding mappings to the controller's context.

Now, let's explore how to pass the statusType to the directive. There are various methods to achieve this, but the most commonly used approaches will be highlighted. One way is to define a scope variable within the controller where the directive element is located like $scope.statusType = 'e'. Then, on the directive element, use status-type="{{statusType}}" with @ for one-way binding to pass the interpolated scope variable inside the attribute. Alternatively, you can directly pass an expression like status-type="{{'e'}}" to evaluate as a string.

Remember to utilize bindToController: true to access the isolated scope values within your directive's controller context (this).

Markup

<div status-count data-class="fa fa-check-square-o" 
   data-title="Prior Auth Count" 
   class="panel panel-default"
   status-type="{{statusType}}">
</div>

Directive

monthlyReportApp.directive('statusCount', function () {
    return {
        //require: 'ngModel',
        restrict: 'AE',
        replace: false,
        templateUrl: 'Scripts/app/views/templates/status-count-template.html',
        link: linker,
        controller: 'PACountCtrl',
        controllerAs: 'ctrl',
        //angular 1.3 + code need below to things scope: {}, bindToController
        scope: {
            statusType: "@"
        },
        bindToController: true
        //angular 1.4 + code need only bindToController
        /*
        bindToController: {
           statusType: "@"
        }
        */
    }

    function linker(scope, el, attrs, ngModel) {
        scope.title = attrs.title;
        scope.class = attrs.class;
    }
});

Answer 2

To dynamically pass the attribute you want, consider using the type attribute. If you plan on using this directive multiple times, ensure that the directive has an isolated scope to increase reusability. Modify your directive to have an isolated scope for better component reusability.

Avoid assigning a controller to the DOM using ng-controller when you already have a directive in place. Remove it from the DOM and apply the controller from the directive itself. Pass the statusType through the directive's attribute so it can be accessed within the isolated scope of the directive. Use scope.statusType in your directive to access the value and adjust your code accordingly to

statusCountService.setType(scope.statusType);

.

When using the controllerAs syntax within your controller and isolating the scope, the scope is not directly bound to the this context of the controller. To address this, use the bindToController property, which employs the angular.bind API method to bind all the scope variables to the controller's this context. Angular 1.3+ offers bindToController: true, while angular 1.4+ simplifies this process by introducing the bindToController property to handle isolated scope and binding mappings to the controller's context.

Now, let's explore how to pass the statusType to the directive. There are various methods to achieve this, but the most commonly used approaches will be highlighted. One way is to define a scope variable within the controller where the directive element is located like $scope.statusType = 'e'. Then, on the directive element, use status-type="{{statusType}}" with @ for one-way binding to pass the interpolated scope variable inside the attribute. Alternatively, you can directly pass an expression like status-type="{{'e'}}" to evaluate as a string.

Remember to utilize bindToController: true to access the isolated scope values within your directive's controller context (this).

Markup

<div status-count data-class="fa fa-check-square-o" 
   data-title="Prior Auth Count" 
   class="panel panel-default"
   status-type="{{statusType}}">
</div>

Directive

monthlyReportApp.directive('statusCount', function () {
    return {
        //require: 'ngModel',
        restrict: 'AE',
        replace: false,
        templateUrl: 'Scripts/app/views/templates/status-count-template.html',
        link: linker,
        controller: 'PACountCtrl',
        controllerAs: 'ctrl',
        //angular 1.3 + code need below to things scope: {}, bindToController
        scope: {
            statusType: "@"
        },
        bindToController: true
        //angular 1.4 + code need only bindToController
        /*
        bindToController: {
           statusType: "@"
        }
        */
    }

    function linker(scope, el, attrs, ngModel) {
        scope.title = attrs.title;
        scope.class = attrs.class;
    }
});

Guide on how to update the controller value in AngularJS directive to trigger data retrieval

Answer №1

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