Invoking a function through an array within the model where said members are declared

Question

Invoking a function through an array within the model where said members are declared

My goal is to consolidate all of my model functionality in one centralized location. I want the ability to access its methods from within the model itself:

JavaScript

/**
 * This application displays "OK" a specified number of times based on the button pressed
 */
angular.module('myApp', [])
.controller('MyCtrl', ['$scope', function MyCtrl($scope) {

  $scope.okModel = {
    oks: [],
    addOne: function(){
      this.oks.push(["OK"]);
    },
    addTwo: function(){
      this.addOK();
      this.addOK();
    },
    buttons: [
      {name:"addOK", action: this.addOne}, // The issue may lie here
      {name:"add2OKs", action: this.addTwo}
    ]
  };
}]);

HTML

<div ng-controller="MyCtrl">

  <!-- display the object containing all the "OK"s -->
  oks: {{okModel.oks}} 

  <!-- render the buttons -->
  <button ng-repeat="item in okModel.buttons" ng-click="item.action()">
    {{item.name}}
  </button>

  <!-- display the "OK"s -->
  <div ng-repeat="ok in okModel.oks">
    {{ok[0]}}
  </div>
</div>

While no errors are thrown, the functionality is not working as expected. The "OK"s are not being added to the model. The root of the problem seems to stem from the okModel.buttons action property.

Here's a plunker showcasing the issue: https://plnkr.co/edit/mDk43yEKSQB37QSmiKJn?p=preview

TL;DR: It appears that the problem lies with this in buttons, what alternative approach should I consider?

Extra question: Being new to Angular, I understand that I might not be utilizing models in the most effective manner. If you have suggestions for a more efficient model implementation, I would appreciate any advice.

javascript angularjs

Answer 1

Answer №1

To implement this in an AngularJS application the "angular" way, it is recommended to use a service to provide the model instead of defining it in the controller:

var app = angular.module('myApp', []);

app.factory('modelService', function() {
  var okModel = {
    oks: [],
  }
  okModel.addOne = function() {
    okModel.oks.push(["OK"]);
  };
  okModel.addTwo = function() {
    okModel.addOne();
    okModel.addOne();
  };
  okModel.buttons = [{
      name: "addOK",
      action: okModel.addOne
    },
    {
      name: "add2OKs",
      action: okModel.addTwo
    }
  ];

  return okModel;
});

app.controller('MyCtrl', ['$scope', 'modelService', function MyCtrl($scope, modelService) {
  $scope.okModel = modelService;
}]);

For a live example, check out this plunk.

Answer 2

To implement this in an AngularJS application the "angular" way, it is recommended to use a service to provide the model instead of defining it in the controller:

var app = angular.module('myApp', []);

app.factory('modelService', function() {
  var okModel = {
    oks: [],
  }
  okModel.addOne = function() {
    okModel.oks.push(["OK"]);
  };
  okModel.addTwo = function() {
    okModel.addOne();
    okModel.addOne();
  };
  okModel.buttons = [{
      name: "addOK",
      action: okModel.addOne
    },
    {
      name: "add2OKs",
      action: okModel.addTwo
    }
  ];

  return okModel;
});

app.controller('MyCtrl', ['$scope', 'modelService', function MyCtrl($scope, modelService) {
  $scope.okModel = modelService;
}]);

For a live example, check out this plunk.

Answer 3

Answer №2

It appears that @reeverd's answer is correct. Here is some additional tidying up.

  $scope.okModel = {
    oks: [],
    addOne: function(){
      oks.push(["OK"]); // Instead of pushing an array with the OK text, you can simply push the OK text itself.
    },
    addMulti: function(cnt){
      for (var ii = 0; cnt < ii; ii++) {
          // this.addOK(); It seems like the addOK function may be undefined.
          $scope.addOne(); // Calls addOne and adds OK to the oks array.
       }
    },
    buttons: [
      {name:"addOK", action: $scope.addOne}, // The issue may be with this line.
      {name:"add2OKs", action: $scope.addMulti(2)}
    ]
  };

Answer 4

It appears that @reeverd's answer is correct. Here is some additional tidying up.

  $scope.okModel = {
    oks: [],
    addOne: function(){
      oks.push(["OK"]); // Instead of pushing an array with the OK text, you can simply push the OK text itself.
    },
    addMulti: function(cnt){
      for (var ii = 0; cnt < ii; ii++) {
          // this.addOK(); It seems like the addOK function may be undefined.
          $scope.addOne(); // Calls addOne and adds OK to the oks array.
       }
    },
    buttons: [
      {name:"addOK", action: $scope.addOne}, // The issue may be with this line.
      {name:"add2OKs", action: $scope.addMulti(2)}
    ]
  };

Answer 5

Answer №3

The issue arises when this within the

{name:"addOK", action: this.addOne}

in the array refers to the object itself rather than the object encompassing the array. To address this, you can implement the following solution:

angular.module('myApp', [])
   .controller('MyCtrl', ['$scope', function MyCtrl($scope) {

// Define the functions that will update
// $scope.okModel.oks
var addOne = function() {
        if ($scope.okModel) {
            $scope.okModel.oks.push("OK");
        }
    },
    addTwo = function() {
        addOne();
        addOne();
    };

    $scope.okModel = {
      oks: [],
      addOne: addOne, // Assign okModel.addOne to the declared functions
      addTwo: addTwo, // Same here
      buttons: [{
          name: "addOK",
          action: addOne // Same here
      }, {
          name: "add2OKs",
          action: addTwo // Same here
      }]
    };
  }]);

Firstly, declare the functions that will alter the $scope.okModel.oks array, and then utilize these functions in both your model methods and model buttons.

UPDATE: For a functional example, refer to this plunker: https://plnkr.co/edit/sKUxjzUyVsoYp3S7zjTb?p=preview

Answer 6

The issue arises when this within the

{name:"addOK", action: this.addOne}

in the array refers to the object itself rather than the object encompassing the array. To address this, you can implement the following solution:

angular.module('myApp', [])
   .controller('MyCtrl', ['$scope', function MyCtrl($scope) {

// Define the functions that will update
// $scope.okModel.oks
var addOne = function() {
        if ($scope.okModel) {
            $scope.okModel.oks.push("OK");
        }
    },
    addTwo = function() {
        addOne();
        addOne();
    };

    $scope.okModel = {
      oks: [],
      addOne: addOne, // Assign okModel.addOne to the declared functions
      addTwo: addTwo, // Same here
      buttons: [{
          name: "addOK",
          action: addOne // Same here
      }, {
          name: "add2OKs",
          action: addTwo // Same here
      }]
    };
  }]);

Firstly, declare the functions that will alter the $scope.okModel.oks array, and then utilize these functions in both your model methods and model buttons.

UPDATE: For a functional example, refer to this plunker: https://plnkr.co/edit/sKUxjzUyVsoYp3S7zjTb?p=preview

Answer 7

Answer №4

Instead of simply referring to this, consider utilizing $scope.okModel instead. The context of this in a function may not always be what you anticipate, as it is determined by the method of invocation.

UPDATE:

To enhance clarity, you can extract the function definitions from okModel in the following manner:

angular.module('myApp', [])
  .controller('MyCtrl', ['$scope', function MyCtrl($scope) {

    var addOne = function() {
      $scope.okModel.oks.push(["OK"]);
    };

    var addTwo = function() {
      addOne();
      addOne();
    };

    $scope.okModel = {
      oks: [],
      addOne: addOne,
      addTwo: addTwo,
      buttons: [{
        name: "addOK",
        action: addOne
      }, {
        name: "add2OKs",
        action: addTwo
      }]
    };
  }]);

Answer 8

Instead of simply referring to this, consider utilizing $scope.okModel instead. The context of this in a function may not always be what you anticipate, as it is determined by the method of invocation.

UPDATE:

To enhance clarity, you can extract the function definitions from okModel in the following manner:

angular.module('myApp', [])
  .controller('MyCtrl', ['$scope', function MyCtrl($scope) {

    var addOne = function() {
      $scope.okModel.oks.push(["OK"]);
    };

    var addTwo = function() {
      addOne();
      addOne();
    };

    $scope.okModel = {
      oks: [],
      addOne: addOne,
      addTwo: addTwo,
      buttons: [{
        name: "addOK",
        action: addOne
      }, {
        name: "add2OKs",
        action: addTwo
      }]
    };
  }]);

Invoking a function through an array within the model where said members are declared

Answer №1

Answer №2

Answer №3

Answer №4

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