Leveraging angular.forEach for JSON Iteration

Question

Leveraging angular.forEach for JSON Iteration

In my app and controller, I am working on creating a "flow chart style" question and answer system. To keep track of the current question and answer, I am using variables like $scope.ActiveQuestion and an array named $scope.ActiveAnswers.

I am struggling to grasp the concept of AngularJS foreach method as I am more familiar with traditional for loops in JavaScript. Despite searching for explanations comparing foreach to for loops, I have come up empty-handed. However, here is what I am attempting to achieve using the foreach method.

For each answerIDs in the current set of

$scope.questions[$scope.ActiveQuestions].answerIDs

, I aim to access the corresponding array in Answers containing that particular idAnswer and then add it to a newly created empty array called $scope.ActiveAnswers. This process will enable me to use ng-repeat in a template to display the necessary answers for that specific question.

Below, you can examine the JSON data alongside my current Controller code:

app.controller('QuestionsCtrl', function($scope, $http) {

    // Fetch Questions data
    $http.get("includes/getQuestions.php")
    .success(function(response) {
        $scope.Questions = response;
        $scope.ValidAnswers = $scope.Questions[$scope.ActiveQuestion].answerIDs.split(",");
    });
    // Fetch Answers data
    $http.get("includes/getAnswers.php")
        .success(function(response) {
            $scope.Answers = response;
        });

    // Assign First Question
    if ($scope.ActiveQuestion == null) {
        $scope.ActiveQuestion = 1;
    };
    $scope.ActiveAnswers = [];
    angular.forEach($scope.Answers, function(idAnswers) {
        angular.forEach($scope.ValidAnswers, function(value) {
            if(value==idAnswers) {
                this.push(Answers)
            };
        });
    },$scope.ActiveAnswers);

});

Questions:

[
    [], {
        "idQuestion": "1",
        "answerIDs": "1",
        "text": "Don't know what to watch?"
    }, {
        "idQuestion": "2",
        "answerIDs": "2,3,4",
        "text": "Okay! First question: How new to anime are you?"
    }, {
        "idQuestion": "3",
        "answerIDs": "5,6,7,8,9,10",
        "text": "So you're new! Awesome, I've got tons of anime for you. But let's get more specific. What type of anime interests you?"
    }, {
        "idQuestion": "4",
        "answerIDs": "11,12,13",
        "text": "Cool, cool. What setting would you like?"
    }
]

I have also compiled an array of answers:

[
    [], {
        "idAnswer": "1",
        "nextQuestion": "2",
        "text": "Click here to get started",
        "animeID": null,
        "checkType": "0"
    }, {
        "idAnswer": "2",
        "nextQuestion": "3",
        "text": "...I've seen some GIFs",
        "animeID": null,
        "checkType": "0"
    }, {
        "idAnswer": "5",
        "nextQuestion": "4",
        "text": "Fantasy Action Adventure",
        "animeID": null,
        "checkType": "0"
    }, {
        "idAnswer": "11",
        "nextQuestion": null,
        "text": "Steampunk (magic, guns, early 1900s)",
        "animeID": "1",
        "checkType": "1"
    }
]

Although no errors are displayed, the ActiveAnswers array remains unfilled. Any assistance on this matter would be highly appreciated.

UPDATE

Furthermore, it is worth mentioning that I initially store my data in a MySQL database and retrieve it using PHP by encoding it into JSON format.

javascript arrays json angularjs angularjs-ng-repeat

Answer 1

Answer №1

To effectively manage your requests, you can utilize the promise feature along with the $q.defer() promise manager.

It is important to note that $http inherently returns a promise.

The $q.defer() function provides 2 essential methods:

resolve(value) : used to resolve the associated promise by providing the final value
reject(reason) : resolves a promise error

In the Controller:

(function(){

function Controller($scope, Service, $q) {


  var defer = $q.defer();

  //creating promises
  var promise1 = Service.get('includes/getQuestions.php"');

  var promise2 = Service.get('includes/getAnswers.php');

  //Creating promise using $q
  var promiseAnswer = defer.promise;

  if ($scope.ActiveQuestion == null) {
      $scope.ActiveQuestion = 1;
  };

  //Retrieving data from promise1 & promise2
  $q.all([promise1, promise2]).then(function(response){
    //Getting question data
    $scope.Questions = response[0].data;
    //Getting answer data
    $scope.Answers = response[1].data;
    $scope.ValidAnswers = $scope.Questions[$scope.ActiveQuestion].answerIDs.split(",");
    $scope.ActiveAnswers = [];

    $scope.Answers.forEach(function(elm){
      $scope.ValidAnswers.forEach(function(value){
        //Accessing elm.idAnswer instead of just elm
        if (value === elm.idAnswer){
          $scope.ActiveAnswers.push(value);
        }
      });
    });

    //Resolving our data
    defer.resolve($scope.ActiveAnswers);

  });

  //Once all data is processed, retrieve the data
  promiseAnswer.then(function(data){
    console.log(data);
  });

}

angular
.module('app', [])
.controller('ctrl', Controller);

})();

Additionally, it is recommended to use a Service for processing requests:

Service

(function(){

  function Service($http){

    function get(url){
      //Returns a promise with the specified URL
      return $http.get(url);
    }

    var factory = {
      get: get
    };

    return factory;

  }

  angular
    .module('app')
    .factory('Service', Service);

})();

When dealing with multiple asynchronous requests, utilizing promise and $q.defer() is considered a best practice.

Answer 2

To effectively manage your requests, you can utilize the promise feature along with the $q.defer() promise manager.

It is important to note that $http inherently returns a promise.

The $q.defer() function provides 2 essential methods:

resolve(value) : used to resolve the associated promise by providing the final value
reject(reason) : resolves a promise error

In the Controller:

(function(){

function Controller($scope, Service, $q) {


  var defer = $q.defer();

  //creating promises
  var promise1 = Service.get('includes/getQuestions.php"');

  var promise2 = Service.get('includes/getAnswers.php');

  //Creating promise using $q
  var promiseAnswer = defer.promise;

  if ($scope.ActiveQuestion == null) {
      $scope.ActiveQuestion = 1;
  };

  //Retrieving data from promise1 & promise2
  $q.all([promise1, promise2]).then(function(response){
    //Getting question data
    $scope.Questions = response[0].data;
    //Getting answer data
    $scope.Answers = response[1].data;
    $scope.ValidAnswers = $scope.Questions[$scope.ActiveQuestion].answerIDs.split(",");
    $scope.ActiveAnswers = [];

    $scope.Answers.forEach(function(elm){
      $scope.ValidAnswers.forEach(function(value){
        //Accessing elm.idAnswer instead of just elm
        if (value === elm.idAnswer){
          $scope.ActiveAnswers.push(value);
        }
      });
    });

    //Resolving our data
    defer.resolve($scope.ActiveAnswers);

  });

  //Once all data is processed, retrieve the data
  promiseAnswer.then(function(data){
    console.log(data);
  });

}

angular
.module('app', [])
.controller('ctrl', Controller);

})();

Additionally, it is recommended to use a Service for processing requests:

Service

(function(){

  function Service($http){

    function get(url){
      //Returns a promise with the specified URL
      return $http.get(url);
    }

    var factory = {
      get: get
    };

    return factory;

  }

  angular
    .module('app')
    .factory('Service', Service);

})();

When dealing with multiple asynchronous requests, utilizing promise and $q.defer() is considered a best practice.

Answer 3

Answer №2

I suggest creating a structure named "Solution" in your code, storing it in an array, and iterating through it like this:

[
 ["Question"],
   ["Solution"]
   {
    "idSolution": "1",
    "nextStep": "2",
    "description": "Click here to begin",
    "animeID": null,
    "validationType": "0"
   },
]

This approach will ensure the loop runs smoothly without any issues.

Answer 4

I suggest creating a structure named "Solution" in your code, storing it in an array, and iterating through it like this:

[
 ["Question"],
   ["Solution"]
   {
    "idSolution": "1",
    "nextStep": "2",
    "description": "Click here to begin",
    "animeID": null,
    "validationType": "0"
   },
]

This approach will ensure the loop runs smoothly without any issues.

Answer 5

Answer №3

Thanks to the collaborative effort of everyone here, I successfully resolved the issues with my code without making any changes to the database. I managed to fix the problems with the foreach loops and although there are still some issues remaining, the main challenges in this task have been addressed. Below is the updated version of my code snippet.

app.controller('QuestionsCtrl', function($scope, $http, $window) {

// Setting the initial active question
if ($scope.ActiveQuestion == null) {
    $scope.ActiveQuestion = 1;
};
// Retrieving questions data
$http.get("includes/getQuestions.php").success(function(responseQuestions) {
    $scope.Questions = responseQuestions;
    $scope.ValidAnswers = $scope.Questions[$scope.ActiveQuestion].answerIDs.split(",");

    // Retrieving answers data
    $http.get("includes/getAnswers.php").success(function(responseAnswers) {
        $scope.Answers = responseAnswers;
        $scope.getActiveAnswers();
    });
});

$scope.getActiveAnswers = function() {
    $scope.ValidAnswers = $scope.Questions[$scope.ActiveQuestion].answerIDs.split(",");
    $scope.ActiveAnswers = [];
    angular.forEach($scope.ValidAnswers, function(answerid) {
        angular.forEach($scope.Answers, function(answer) {
            if (answer.idAnswer == answerid) {
                $scope.ActiveAnswers.push(answer);
              };
          });

      }, $scope.ActiveAnswers);
}

$scope.answerclick = function(nextQuestion) {
    $scope.ActiveQuestion = nextQuestion;
    $scope.getActiveAnswers();
};

});

Answer 6

Thanks to the collaborative effort of everyone here, I successfully resolved the issues with my code without making any changes to the database. I managed to fix the problems with the foreach loops and although there are still some issues remaining, the main challenges in this task have been addressed. Below is the updated version of my code snippet.

app.controller('QuestionsCtrl', function($scope, $http, $window) {

// Setting the initial active question
if ($scope.ActiveQuestion == null) {
    $scope.ActiveQuestion = 1;
};
// Retrieving questions data
$http.get("includes/getQuestions.php").success(function(responseQuestions) {
    $scope.Questions = responseQuestions;
    $scope.ValidAnswers = $scope.Questions[$scope.ActiveQuestion].answerIDs.split(",");

    // Retrieving answers data
    $http.get("includes/getAnswers.php").success(function(responseAnswers) {
        $scope.Answers = responseAnswers;
        $scope.getActiveAnswers();
    });
});

$scope.getActiveAnswers = function() {
    $scope.ValidAnswers = $scope.Questions[$scope.ActiveQuestion].answerIDs.split(",");
    $scope.ActiveAnswers = [];
    angular.forEach($scope.ValidAnswers, function(answerid) {
        angular.forEach($scope.Answers, function(answer) {
            if (answer.idAnswer == answerid) {
                $scope.ActiveAnswers.push(answer);
              };
          });

      }, $scope.ActiveAnswers);
}

$scope.answerclick = function(nextQuestion) {
    $scope.ActiveQuestion = nextQuestion;
    $scope.getActiveAnswers();
};

});

Leveraging angular.forEach for JSON Iteration

Answer №1

Answer №2

Answer №3

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