解决所有资源后如何执行功能？

Question

How do I delay execution of a function until after all of my $resources have resolved? My goal here is to be able to parse though the log array after all $resources have resolved and push a single success notification to the UI instead of pushing one notification per each success.

I've based my code below off of this question angular -- accessing data of multiple http calls - how to resolve the promises . I realize that $scope.promises is empty because item.$save() doesn't return anything but I hope you can see that I'm trying to push the unresolved promise to the promises array.

$scope.save = function () {
  $scope.promises = [];
  $scope.log = [];

  angular.forEach($scope.menuItems, function(item) {
    $scope.promises.push(item.$save(function(menu){
      debugger;                            // execution gets here 2nd
      console.debug("success");
      $scope.log.push(msg: 'success');
    }));
   }, this);

  $q.all($scope.promises).then(function() {
    debugger;                              // execution gets here 1st
    console.debug("all promises resolved");
  });
};

Answer 1

Since $save does not return a promise, you will need an intermediate one:

  angular.forEach($scope.menuItems, function(item) {
    var d = $q.defer();   // <--- the intermediate promise
    item.$save(
      function(menu){
        debugger;
        console.debug("success");
        $scope.log.push(msg: 'success');
        d.resolve(menu);  // <--- resolving it, optionally with the value
      },
      function(error){
        d.reject(error);  // <--- rejecting it on error
      }
    );
    $scope.promises.push(d.promise);
   }, this);

By the way, do not forget to throw away the array of promises, or you will keep garbage:

$q.all($scope.promises).then(...).always(function() {
    $scope.promises = null;
});

And, if $scope.promises is NOT exposed to the view, it does not need to be in the scope; it can be just a var.