AngularJS Resolving a Promise

Question

I am learning how to use resolve from an example , and applying it on to my Todo script.

Then I realised an issue, that the example is only showing me how to resolve GET call to get me the Todo List when I first visit this route.

However, in the same route same page I have an Add button to POST new todo item, also a Clear button to DELETE completed items.

Looking at my $scope.addTodo = function() { and $scope.clearCompleted = function () { I want to Resolve my TodoList again after the action. How can I do that?

Here is my code. In my code, the initial resolve: { todos: TodosListResl } is working, it hits TodosListResl function and produces the promise. However, I don't know what to do with addTodo and clearComplete when I want to resolve the todo list again.

main.js

var todoApp = angular.module('TodoApp', ['ngResource', 'ui']);
todoApp.value('restTodo', 'api/1/todo/:id');

todoApp.config(function ($locationProvider, $routeProvider) {
    $routeProvider.when("/", { templateUrl: "Templates/_TodosList.html", 
        controller: TodosListCtrl, resolve: { todos: TodosListResl } });
    $routeProvider.otherwise({ redirectTo: '/' });
});

//copied from example, works great
function TodoCtrl($scope, $rootScope, $location) {
    $scope.alertMessage = "Welcome";
    $scope.alertClass = "alert-info hide";

    $rootScope.$on("$routeChangeStart", function (event, next, current) {
        $scope.alertMessage = "Loading...";
        $scope.alertClass = "progress-striped active progress-warning alert-info";
    });
    $rootScope.$on("$routeChangeSuccess", function (event, current, previous) {
        $scope.alertMessage = "OK";
        $scope.alertClass = "progress-success alert-success hide";

        $scope.newLocation = $location.path();
    });
    $rootScope.$on("$routeChangeError", 
        function (event, current, previous, rejection) {
        alert("ROUTE CHANGE ERROR: " + rejection);
        $scope.alertMessage = "Failed";
        $scope.alertClass = "progress-danger alert-error";
    });
}
//also copied from example, works great.
function TodosListResl($q, $route, $timeout, $resource, restTodo) {
    var deferred = $q.defer();
    var successCb = function(resp) {
        if(resp.responseStatus.errorCode) {
            deferred.reject(resp.responseStatus.message);
        } else {
            deferred.resolve(resp);
        }
    };
    $resource(restTodo).get({}, successCb);
    return deferred.promise;
}
//now, problem is here in addTodo and clearCompleted functions, 
//how do I call resolve to refresh my Todo List again? 
function TodosListCtrl($scope, $resource, restTodo, todos) {
    $scope.src = $resource(restTodo);
    $scope.todos = todos;
    $scope.totalTodos = ($scope.todos.result) ? $scope.todos.result.length : 0;

    $scope.addTodo = function() {
        $scope.src.save({ order: $scope.neworder, 
                          content: $scope.newcontent, 
                          done: false }); 
                        //successful callback, but how do I 'resolve' it?
    };
    $scope.clearCompleted = function () {
        var arr = [];
        _.each($scope.todos.result, function(todo) {
            if(todo.done) arr.push(todo.id);
        });
        if (arr.length > 0) $scope.src.delete({ ids: arr }); 
        //successful callback, but how do I 'resolve' it?
    };   
}

Answer 1

I think you're missing the point of resolve . The point of resolve is to " delay route change until data is loaded . In your case, you are already on a route, and you want to stay on that route. But, you want to update the todos variable on the successful callback. In this case, you don't want to use resolve . Instead, just do what needs to be done. For example

$scope.addTodo = function() {
    $scope.src.save({ order: $scope.neworder, 
                      content: $scope.newcontent, 
                      done: false }, function () {
        todos.push({ order: $scope.neworder, 
                      content: $scope.newcontent, 
                      done: false });
    }); 
                    //successful callback, but how do I 'resolve' it?
};

As a side point, I noticed you're using _ most likely from the Underscore library. You don't need to use another library for that because Angular already has $angular.forEach() .