Using forge.prefs always returns undefined - trigger.io

Question

I'm trying to use forge.prefs to store variables but nothing seems to be saving.
I am using the following:
var all = forge.prefs.keys(function(keysArray){ return keysArray},
function(content){return content});
forge.logging.log(all);
But this always returns undefined
I am also having the same issue with setting, nothing seems to be working.
var set = forge.prefs.set(key,value,function(){},function(content){return content;});
forge.logging.log(set);
Again returns undefined and no error or anything.
Am I doing something wrong?
Using the docs found here
UPDATE
I won't to do something like the following:
var get = forge.prefs.get(key,
function(value){return value;},
function(error){forge.logging.log(error);
});
if(get){
// do something here
}else{
// do something here
}

Answer 1

Those methods are asynchronous which means that subsequent code might be executed before the callback success and error functions are returned. All subsequent code that relies on the outcome of this should run within the callback:
forge.prefs.keys(function(keysArray){ // success
forge.logging.log(keysArray);
// subsequent code relying on a positive outcome here ...
},
function(error){ // error
forge.logging.log('Something bad happened: ' + error);
});
forge.prefs.set(key, value, function(){ // success
forge.logging.log(key + ' was properly set);
// subsequent code relying on a positive outcome here ...
},
function(error){ // error
forge.logging.log('Something bad happened: ' + error);
});
UPDATE: use this to achieve the updated part of your question:
var get;
forge.prefs.get(key, function(value){ // success
get = value;
forge.logging.log('Found value: ' + get);
// subsequent code here ...
},
function(error){ // error
forge.logging.log('Something bad happened: ' + error);
});

Answer 2

It appears you're not returning anything in the forge.pref.set success function. Your return content; is in the error function so if it's not throwing an error you won't return anything.
Try this:
var set = forge.prefs.set(key,value,function(){ return value; },function(content){return content;});
forge.logging.log(set);