Promises, promises – how many times have I heard that phrase, I wonder?
Unlike in real life, when promises made are often broken, we can always guarantee that Promises made in jQuery will be satisfied at some point. Granted, the answer may not always be positive one, but yes, there will at least be a response to a Promise.
A question though, I hear you ask – why, if most events already have callback options built in, do we need to use jQuery's .promises()?
The simple answer is that we have far more control over constructing and reading Promises. For example, we can set a single callback that can be applied to multiple Promises; we can even set a Promise to only fire once, if needed! The beauty though is that using Promises makes it easier to read the code, and chain multiple methods together:
var myEvent = function(){
return $(selector).fadeIn('fast').promise();
};
$.when( myEvent()).done( function(){
console.log( 'Task completed.' );
});We can...