Javascript `this` statement not working

Question

After calling this $http request (with server.refresh();)

MinecraftServer.prototype.refresh = function(){
    return $http.get("http://mcping.net/api/" + this.ip).then(this.acceptData);
}

This function's this is the window object, instead of the MinecraftServer object:

MinecraftServer.prototype.acceptData = function(data){
    data = data.data

    if(data && data.online){
        this.online = data.online;
        //do more stuff       
    } else { // do more stuff }
}

So instead of the MinecraftServer object getting it's attributes updated, the window gets the attributes.

In case this will help, here is my abriged factory code:

.factory('MinecraftServer',function($http){
    function MinecraftServer(name, ip) { //does stuff }

    MinecraftServer.prototype.acceptData = function(data){
        data = data.data

        if(data && data.online){
            this.online = data.online;
            //do more stuff       
        } else { // do more stuff }
    }
    MinecraftServer.prototype.refresh = function(){return $http.get("http://mcping.net/api/" + this.ip).then(this.acceptData);}
    MinecraftServer.build = function(name, ip){return new MinecraftServer(name, ip)};
    return MinecraftServer;
})

You might want to read more about [how *this* works in JavaScript](http://stackoverflow.com/questions/3127429/how-does-the-this-keyword-work). It'll definitely help you get a better understanding. — fstanis, Aug 15 '15 at 14:21

score 5 · Accepted Answer · answered Aug 15 '15 at 14:20

5

this as a callback is using some other this.

Use .bind:

return $http.get("http://mcping.net/api/" + this.ip).then(this.acceptData.bind(this));

answered Aug 15 '15 at 14:20

Daniel A. White

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This seems like it works! Thanks. (I'll accept it as soon as it allows me too) – Ben Aubin Aug 15 '15 at 14:24
@charlietfl you have to bind to the function you want to modify `this`. – Daniel A. White Aug 15 '15 at 14:26

Javascript `this` statement not working

1 Answers1