Pattern for wrapping an Asynchronous JavaScript function to make it synchronous

Question

I\'m working with a JavaScript API where most of the functions are asynchronous. The API is the WebKit JavaScript Database API which is a binding to a subset of functionali

Answer 1

You can try something like:

function synch()
{
    var done = false;
    var returnVal = undefined;

    // asynch takes a callback method
    // that is called when done
    asynch(function(data) {
        returnVal = data;
        done = true;
    });

    while (done == false) {};
    return returnVal;
}

But that may freeze your browser for the duration of the asynch method...

Or take a look at Narrative JavaScript: Narrative JavaScript is a small extension to the JavaScript language that enables blocking capabilities for asynchronous event callbacks. This makes asynchronous code refreshingly readable and comprehensible.

http://neilmix.com/narrativejs/doc/index.html

Mike