Question

I have a function that calls another function and I want to store the returned result in a variable:

function trigger_gridly(){
    var channel_name = get_channel_name();
}

The called function triggers an AJAX request, which triggers a callback receiving JSON:

function get_channel_name(){
    var channel_name;     
    $.getJSON(APPLICATION_DOMAIN + "channels/new.json?callback=?", null, handleJson);
}

function handleJson(channel){
    var channel_name = channel.name;
    return channel_name;
}

The problem is that the channel_name in trigger_gridly() does not receive the value of channel_name in the handleJson callback function. How can I expose the data in the callback to the trigger_gridly() function?

Answer 1

it’s quite ugly, but this will work, asynchronous processes are always a bit tricky getJSON is async.

function get_channel_name(fn) {
    $.getJSON(APPLICATION_DOMAIN + "channels/new.json?callback=?", null, function(channel) {
        fn(channel.name);
    });
}

var channel_name;
get_channel_name(function(name) {
    channel_name = name;
});
// but here channel_name is still undefined