HTML页面是否在AJAX调用之前加载？

Question

In my HTML Page, I have a button tag that looks like so:

<button ng-hide="alreadyFreinds()" type="button" class="btn btn-primary btn-lg">Friend</button>

However, when I try to access certain parts of the alreadyFriends function shown below, I get an error saying that TypeError: Cannot read property 'length' of undefined

  $scope.alreadyFreinds = function(){
    for(var i = 0; i < $scope.user.friends.length; i++){
      if($scope.user.friends[i].username === $scope.realUserViewing.username && 
        $scope.user.friends[i].requested == true && $scope.user.friends[i].pending == true){
        return true;
      }
    }
  };

However, the confusing part is that I already have $scope.user.friends and $scope.user defined in a few lines above this function like so:

  $http.get('/api/users/me')
    .then(function(result){
      $scope.user = result.data;
  });

I am a bit confused as to why the HTML page loads and calls tbe alreadyFriends function before the Ajax call completes. I tried to use promises to help me solve this and I found

AngularJS: How to execute a controller function AFTER completion of AJAX call in a service?

But this did not help me too much because when I did

  $http.get('/api/users/me')
    .then(function(result){
      var deferred = $q.defer();
      $scope.user = result.data;
      deferred.resolve($scope.alreadyFreinds);
      return deferred.promise;
  });

This did work, but the HTML page still loads up before the AJAX call is completed. Any ideas how to fix this? Thanks!

Answer 1

    <button ng-hide="alreadyFreinds()" 
     ng-if="user.length > 0"
     type="button" class="btn btn-primary btn-lg">Friend</button>

By setting ng-if your button will be visible and your alreadyFreinds() will be fired when your http call response get back.