javascript - setting div background image only works on page load -

i set div background setpic() function. use changepic() function update picture

html

div.profileimg(id="img", ng-style="imagepath") 

angular/js

function setpic() {     console.log("in set pic")     var url = '/api/image?spotid=' + $window.sessionstorage.getitem("currentgarage")     $http.get(url).then(         function successcallback(response) {             console.log("success image")             $scope.imagepath = {};             $scope.imagepath = {                 background: 'url(' + url + ')'             };         },         function errorcallback(response) {             console.log("fail image")         });  }   changepic = function(fd) {     url = "/api/spot/pic/post?spotid=" + $window.sessionstorage.getitem("currentgarage");     $http.post(url, fd, {         headers: {             'content-type': undefined         },         transformrequest: angular.identity     }).then(         function successcallback(response) {             console.log("success post image")             setpic();         },         function errorcallback(response) {             console.log("fail post image")         }); }; 

the setpic() function called once @ beginning of controller (works), , once inside success clause of changepic() function. why calling setpic() after page load not work?

one more question. notice how define functions differently. 1 function name() , other name = function(). setpic() called controller , not dom. if change form of function site not build , see {{}} in fields. changepic() registered in onclick of button , if change form of function, click not register. mind-blowing craziness here. should go take javascript/angular course before attempting code anymore?