I need to wait for document readyness in my JavaScript, to insert a div at the bottom of the body.
I want to:
- make this JavaScript file as small as possible (compile it down to < 1kb if possible)
- inline the code that provides the document readyness in a closure (without exporting it)
Inlining the whole jQuery source in my file would be too big, so I'm looking for other methods. window.onload would work, but I specifically want document readyness, and not wait for the window.onload event.
Does anyone know a JS snippet that can do this? Or should I just copy part of jQuery's source?
EDIT:
I managed to crawl the jQuery source and put together with the following snippet:
var ready = (function () {
var ready_event_fired = false;
var ready_event_listener = function (fn) {
// Create an idempotent version of the 'fn' function
var idempotent_fn = function () {
if (ready_event_fired) {
return;
}
ready_event_fired = true;
return fn();
}
// The DOM ready check for Internet Explorer
var do_scroll_check = function () {
if (ready_event_fired) {
return;
}
// If IE is used, use the trick by Diego Perini
// http://javascript.nwbox.com/IEContentLoaded/
try {
document.documentElement.doScroll('left');
} catch(e) {
setTimeout(do_scroll_check, 1);
return;
}
// Execute any waiting functions
return idempotent_fn();
}
// If the browser ready event has already occured
if (document.readyState === "complete") {
return idempotent_fn()
}
// Mozilla, Opera and webkit nightlies currently support this event
if (document.addEventListener) {
// Use the handy event callback
document.addEventListener("DOMContentLoaded", idempotent_fn, false);
// A fallback to window.onload, that will always work
window.addEventListener("load", idempotent_fn, false);
// If IE event model is used
} else if (document.attachEvent) {
// ensure firing before onload; maybe late but safe also for iframes
document.attachEvent("onreadystatechange", idempotent_fn);
// A fallback to window.onload, that will always work
window.attachEvent("onload", idempotent_fn);
// If IE and not a frame: continually check to see if the document is ready
var toplevel = false;
try {
toplevel = window.frameElement == null;
} catch (e) {}
if (document.documentElement.doScroll && toplevel) {
return do_scroll_check();
}
}
};
return ready_event_listener;
})();
// TEST
var ready_1 = function () {
alert("ready 1");
};
var ready_2 = function () {
alert("ready 2");
};
ready(function () {
ready_1();
ready_2();
});
Thank you very much for helping me find this in the jQuery source. I can now put all this in a closure and do my work without exporting any functions and polluting the global scope.
