angularjs服务函数调用自身

Question

I want to create a startService function in angularjs service (factory). I want to startService function check if it can start service and if not it will invoke itself with a timeout and than checks again.

startService: function() {      
      if(!someComaprison) {
        $timeout(this.startService, 5000);
        return;
      }

      //starts service
    },

But in the next start of the function it crashes because this is undefined. How to make such a loop in services? I have no problem doing it with controllers functions?

Answer 1

You need to pass context (in this case-> this ) too. Try like this:

$timeout(this.startService.bind(this), 5000);

Answer 2

in order to keep the right this context,you need to bind the function to this

$timeout(this.startService.bind(this), 5000);

or the function executed in the timeout will not know what this refers to.

have a look a the following article :

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/this

EDIT : for the other issue :

var that = this;

this.startHttpRequest = function(userId) {
    var httpRequest = $http.post(somedata....);


    httpRequest.success(function(data){
      that.startHttpRequest(data.userId);
    });
  }

But, dont ask 2 different questions like that, or edit your first question instead of posting a question as an answer.