The use of $http in AngularJS

Question

I have learnt angularJS for three days,but I have some questions during my study.

well,in the "Run Block":

angular.module("techNodeApp",["ngRoute"]).
run(function($window,$rootScope,$http,$location){
     $http({
        url:"/api/validate",
        method:"GET"
  }).success(function(user){
        console.log("success");        
        $rootScope.me=user;
        $location.path("/");
  }).error(function(data){
        console.log("error");
        $location.path("/login");
  });

     $rootScope.logout=function(){
        $http({
         url:"/api/logout",
         method:"GET"
    }).success(function(){
         console.log("I've logged out");
         $rootScope.me=null;
         $location.path("/login");
    })
   }
})

In the server(Node.js):

app.get("/api/validate",function(req,res){
    console.log("I can hear you FE");     
});

app.get("/ajax/validate",function(req,res){
    var _userId=req.session._userId;
    if(_userId){
        Controllers.findUserById(_userId,function(err,user){
            if(err){
                res.json(401,{msg:err});
            }else{
                res.json(user);
            }
        })
    }else{
        res.json(401,null);
    }
});

The first I enter the website I haven't log in,so I thought when the app start run.It must go to the page of " http://localhost:3000/login ".But it went to " http://localhost:3000 " and it can't print the string "I can hear you FE" in the cmd.

Answer 1

1) Your node.js app doesn't respond with a user when a request is made to /api/validate . So in your angular app, when that AJAX request succeeds, user will be undefined .

2) When that request succeeds, you set $location.path to / . So it will obviously go to localhost:3000/ and not to localhost:3000/api/validate .

3) $http makes an AJAX request, it doesn't change the location of browser (URL that browser loads). $location.path does that.

4) Currently it should actually display I can hear you FE in node.js output, unless you have some other problems with your node.js configuration or unless you forget to bootstrap your angular app (typically with ng-app directive in your html).