Things I’ve Learnt About JavaScript

I’m continuing with my HTML5 experiment. It now has context menus (aka right-click popup menus) and editable text. I’m still astounded how much one can achieve with little code. If one can work out the right code to use. For example, this single function is all I needed to write to implement context menus (with a little bit of additional CSS and jQuery support):

function dubbiyaPopup(x, y, items) {
var clear = function () {
$('.dubbiyaPopupOuter').remove();
};
clear();

$('body').append('
');
$('.dubbiyaPopupOuter').css("left", x + "px");
$('.dubbiyaPopupOuter').css('top', y + 'px').fadeIn(200);
for (var i = 0; i < items.length; i++) {
var item = items[i];

var s = '#dubbiyaPopupItem' + i;
$('.dubbiyaPopupOuter').append('
' + item.text + '
');
$(s);
}
$('.dubbiyaPopupOuter').click(function (e) {
var id = e.srcElement.id;
var s2 = 'dubbiyaPopupItem.';
if (id.substring(0, s2.length) === s2) {
var num = parseInt(id.substring(s2.length));
var itemFunction = items[num].itemFunction;
itemFunction.call(this);
}
});

$(document).one('click', null, function() {
clear()
});
}

Although there’s not much code there, it took me a couple of hours to make it work properly. Actually, I’m not sure if it works properly because testing it properly is awkward.

I’m subjecting myself to a self-run crash course in everything JavaScript. Here’s what I’ve learnt:

  • JavaScript is almost certainly the most-used programming language on the planet. That’s because we all surf all day, and the only language that runs within a web browser is JavaScript.
  • JavaScript was created in only 10 days, under enormous pressure from his managers, by one person, Brendan Eich. This means it never got the chance to be tested thoroughly and refined.¬†Eich, by the way, means Oak in German, and the Java programming language – which has almost nothing to do with JavaScript – was originally called Oak.
  • To make using JavaScript bearable, one should use a JavaScript library such as jQuery or Prototype.
  • The StackOverflow programmer’s Q&A site is indispensable for JavaScript programming.
  • JavaScript has some very good bits and some very bad bits. JavaScript : The Good Parts is important to read to work out which bits are good.
  • JavaScript is really hard to debug.