How to properly execute a function inside ng-repeat

Question

SITUATION:

I am making an app in AngularJs that assign permissions. In order to do this i have three nested ng-repeat.

First loop: display PERMISSION GROUP

Second loop: For each permission group display CATEGORIES. Inside this loop execute a function that will get all the SUB CATEGORIES for each category

Third loop: display SUB CATEGORIES

ISSUE:

The problem is in the execution of the function inside the second loop.

ATTEMPT 1 - ng-init:

<div class="row" ng-repeat="permission_group in list_permission_groups">
  <div class="col-sm-3">
    <h3>
      {{permission_group.permission_group_name}} 
    </h3>
  </div>
  <div class="col-sm-9">
    <ul>
      <li ng-repeat="category in list_categories">
        <span>
          {{ category.name }} 
        </span>            
        <div class="checkbox">
          <label>                
            <div ng-init="temp_result = get_Sub_Categories(category.category_id)">                  
              <p ng-repeat="sub_category in temp_result">
                {{ sub_category.name }} 
              </p>                  
            </div>               
          </label>
        </div>           
      </li>
    </ul>
  </div>
</div>

In the controller:

$scope.get_Sub_Categories = function(category_id) {
    $http({

        url: base_url + 'main/json_get_list_sub_categories',
        data: {
            category_id: category_id
        },
        method: "POST"

    }).success(function(data) {

        return data;

    });

}

Te behavior is quite strange. Porbably due to dirty checking the page is loaded 682 times. No result is displayed.

ATTEMPT 2 - ng-click: (only for debug)

<div class="row" ng-repeat="permission_group in list_permission_groups">

  <div class="col-sm-3">

    <h3>
      {{permission_group.permission_group_name}} 
    </h3>

  </div>

  <div class="col-sm-9">
    <ul>
      <li ng-repeat="category in list_categories">
        <span>
          {{ category.name }} 
        </span>

        <div class="checkbox">
          <label>

            <button ng-click="get_Sub_Categories(category.category_id)">
              GET SUB-CATEGORIES
            </button>

            {{ list_sub_categories }} 

          </label>
        </div>

      </li>
    </ul>
  </div>
</div>

In the controller:

$scope.get_Sub_Categories = function(category_id) {
    $http({

        url: base_url + 'main/json_get_list_sub_categories',
        data: {
            category_id: category_id
        },
        method: "POST"

    }).success(function(data) {

        $scope.list_sub_categories = data;

    });

}

This time the page is loaded only once. If I press the button the proper sub-categories are displayed BUT of course not only for the corresponding category but FOR ALL, because i am modifying the var in the global scope.

THE AIM:

What I want to obtain is simply displaying all the proper sub-categories for each category. Without using a button, but simply see all the proper content as soon as the page load. But i don't understand how can this be done properly in AngularJs.

THE QUESTION:

How can i properly execute a function inside a ng-repeat that return and display different data for each loop?

EDIT - DUMP OF EXAMPLE OF SUB-CATEGORIES FOR ONE CATEGORY:

[{
    "sub_category_id": "1",
    "name": "SUB_CATEGORY_1",
    "category_id_parent": "1",
    "status": "VISIBLE"
}, {
    "sub_category_id": "2",
    "name": "SUB_CATEGORY_2",
    "category_id_parent": "1",
    "status": "VISIBLE"
}, {
    "sub_category_id": "3",
    "name": "SUB_CATEGORY_3",
    "category_id_parent": "1",
    "status": "VISIBLE"
}, {
    "sub_category_id": "4",
    "name": "SUB_CATEGORY_4",
    "category_id_parent": "1",
    "status": "VISIBLE"
}]

Answer 1

Calling a function inside ng-repeat is same as normal one. Since you need to display the sub categories at the time of page loading its better to get these data beforehand. Asynchronously loading sub categories will not fit into this scenario.

Here is a minimal snippet achieving this (JS Fiddle)

<div ng-app="app" ng-controller="ctrl">
    <div ng-repeat="category in model.categories"> <span> Category: {{ category.name }} </span>

      <p ng-repeat="subCategory in getSubCategories(category.Id)">{{ subCategory.name }}</p>
   </div>
</div>

Controller

angular.module("app", [])
.controller('ctrl', ['$scope', function ($scope) {
$scope.model = {
    categories: [{
        "Id": 1,
        name: '1'
    }, {
        "Id": 2,
        name: '2'
    }],
    subCategories: [{
        "parentId": 1,
        name: 'a1'
    }, {
        "parentId": 1,
        name: 'a2'
    },
                   {
        "parentId": 2,
        name: 'a3'
    }]
}
$scope.getSubCategories = function(parentId){
    var result = [];
    for(var i = 0 ; i < $scope.model.subCategories.length ; i++){
        if(parentId === $scope.model.subCategories[i].parentId){
            result.push($scope.model.subCategories[i]);               
        }
    }
    console.log(parentId)
    return result;
}}])

Answer 2

The subcategory example did not work for my case and it took my code into an infinte loop for some reason. may be because i was using an accordion.

I achieved this function call inside ng-repeat by using ng-init

<td class="lectureClass" ng-repeat="s in sessions" ng-init='presenters=getPresenters(s.id)'>
      {{s.name}}
      <div class="presenterClass" ng-repeat="p in presenters">
          {{p.name}}
      </div>
</td> 

The code on the controller side should look like below

$scope.getPresenters = function(id) {
    return SessionPresenters.get({id: id});
};

While the API factory is as follows:

angular.module('tryme3App').factory('SessionPresenters', function ($resource, DateUtils) {

        return $resource('api/session.Presenters/:id', {}, {
            'query': { method: 'GET', isArray: true},
            'get': {
                method: 'GET', isArray: true
            },
            'update': { method:'PUT' }
        });
    });