CODEWITHSUNDEEP
javascript
Charlie
Charlie

Reputation: 11767

Access variable in function within function outside of function?

I have the following code which registers my iOS device with my APNS server:

pushNotification.registerDevice({
    alert: true,
    badge: true,
    sound: true,
    pw_appid: "***",
    appname: "***"
},

function (status) {
    var deviceToken = status['deviceToken'];
},

function (status) {
    console.warn('failed to register : ' + JSON.stringify(status));
    navigator.notification.alert(JSON.stringify(['failed to register ', status]));
});

This runs onLoad, but I need to access deviceToken outside of the scope of pushNotification.registerDevice() function (status).

Is it possible, in this case, to access deviceToken which is inside a function within a function, outside of the function?

I thought I could make it a global variable, by using window.deviceToken, then calling that later on, but it returns undefined.

Upvotes: 1

Views: 157

Answers (3)

Aesthete
Aesthete

Reputation: 18850

If you're assigning the token to a global and finding its undefined when you try to use it, you will probably find its because the registerDevice ajax hasn't yet received a response.

Try separating your callback into a separate function, and launch any dependant functions from there.

function registerSuccess(status) {
  // Store token globally
  token = status["deviceToken"];
  // or pass as an argument
  // call functions that depend on the token
  Foo(token);
  Bar(); // uses global
}

Personally I would try and pass as an argument, save polluting the global namespace.

Upvotes: 2

Blender
Blender

Reputation: 298096

You could give deviceToken a broader scope:

var deviceToken;

pushNotification.registerDevice({
    alert: true,
    badge: true,
    sound: true,
    pw_appid: "***",
    appname: "***"
},

function(status) {
    deviceToken = status['deviceToken'];
},

function(status) {
    console.warn('failed to register : ' + JSON.stringify(status));
    navigator.notification.alert(JSON.stringify(['failed to register ', status]));
});​

Upvotes: 3

jfriend00
jfriend00

Reputation: 707158

Change it to make deviceToken a global variable so it is available in outside scopes by referencing the global scope directly.

function (status) {
    window.deviceToken = status['deviceToken'];
},

If you just want it in a parent scope, not necessarily at the global scope, you can define it in the desired parent scope and then NOT redeclare it in your function:

var deviceToken;

pushNotification.registerDevice({
    alert: true,
    badge: true,
    sound: true,
    pw_appid: "***",
    appname: "***"
},

function (status) {
    deviceToken = status['deviceToken'];
},

function (status) {
    console.warn('failed to register : ' + JSON.stringify(status));
    navigator.notification.alert(JSON.stringify(['failed to register ', status]));
});

Upvotes: 2

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