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POChaining promise and defered with a for loop in angular application
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copied!<p>I try to use promise and defered in an angular application.</p> <p>I use two functions <code>$scope.checkQuestions()</code> and <code>$scope.saveExerciseApi()</code> but the problem is that the second one is launched before the first has finished wich is not what I had expected.</p> <p>The first one call promises to update each questions (with a REST service) and then update <code>$scope.formQuestion[]</code> array which is used in a form on the page.</p> <p><code>$scope.Questions</code> and <code>$scope.Exercises</code> are already promise object to update and create entities in a REST service.</p> <p><code>$scope.formQuestion</code>, <code>$scope.formexercise</code>, <code>$scope.exercises</code> are data used on the webpage.</p> <pre><code>$scope.checkQuestions = function(){ deferred = $q.defer() for (i in $scope.formQuestion){ if ($scope.formQuestion[i].pk == null){ //Save $scope.Questions.add($scope.formQuestion[i]).then(function(newquestion){ deferred.resolve(newquestion); $scope.formQuestion[i] = newquestion; }); } } return deferred.promise; } $scope.saveExerciseApi = function() { if ($scope.formexercise.pk == null){ //Save $scope.Exercises.add($scope.formexercise).then(function(newexercise){ $scope.exercises.push(newexercise); $scope.showform = false; }); } } $scope.saveExercise = function() { $scope.checkQuestions().then($scope.saveExerciseApi); } </code></pre> <p>EDIT:</p> <p>The following change doesn't fix the problem.</p> <p>1) <code>$scope.formexercise.questions</code> is still empty and </p> <p>2) $scope.saveExerciseApi launch never occured </p> <p>Is there anything wrong in the following logic ? Is there a better and cleaner way to loop over and update local data for <code>questions</code> and after to update <code>exercise</code> data ?</p> <pre><code>$scope.checkQuestions = function(){ deferred = $q.defer() $scope.formexercise.questions = Array (); for (i in $scope.formQuestion){ if ($scope.formQuestion[i].pk == null){ $scope.Questions.add($scope.formQuestion[i]).then(function(newquestion){ $scope.formQuestion[i] = newquestion; $scope.formexercise.questions.push($scope.formQuestion[i].pk); if ($scope.formQuestion.length == i+1){ deferred.resolve(newquestion); } }); } else { $scope.Questions.edit($scope.formQuestion[i].pk, $scope.formQuestion[i]).then(function(updatequestion){ $scope.formexercise.questions.push($scope.formQuestion[i].pk); if ($scope.formQuestion.length == i+1){ deferred.resolve(udpatequestion); } }); } } return deferred.promise; } </code></pre>

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