concat.js 
Chainable DOM Builder
How to use
$C(parentNode, replace, direct)
...
.end();
parentNode is a DOM element to put the result into.
replace is a boolean value indicates that parentNode's content should be
replaced with newly built content (newly built content will be appended to the
current one when replace is coerced to false).
direct indicates that everything should be rendered directly to parentNode
right away (skipping documentFragment creation).
Return value is the result's documentFragment in case parentNode is not
passed. When parentNode is passed, return value is undefined.
Usage example
var tmp = 0;
$C(document.body)
.div({'class': 'ololo', 'style': 'background-color: red; height: 100px;'})
.act(function() {
this.addEventListener('click', function() { alert(5555); });
})
.ul()
.repeat(2)
.li()
.text('aaa')
.end(4)
.repeat(3)
.span({'style': function() { return 'border: 1px solid green;'}})
.text(function(index) {
return index + ' ' + Math.random();
})
.end()
.end()
.repeat(function() { return ++tmp <= 5; })
.p()
.text(function(index) { return index + ' ' + tmp; })
.end()
.end()
.div()
.text('hello')
.text('<br>', true)
.text('world')
.end()
.test(1 === 1)
.elem('section')
.text('ololo')
.end()
.end()
.test(function() { return false; })
.text('alala')
.end()
.each([9, 8, 7])
.p()
.text(function(item, index, arr) {
return index + ' ' + item;
})
.repeat(2)
.div()
.text(function(index) { return index; })
.end()
.end()
.div()
.text(function(item, index, arr) { return index + ' ' + item; })
.end(3)
.choose()
.when(false).text('1111').end()
.when(true).text('2222').end()
.otherwise().text('3333').end()
.end()
.end();
Will append the following to <body> tag:
<div class="ololo" style="background-color: red; height: 100px;">
<ul>
<li>aaa</li>
<li>aaa</li>
</ul>
</div>
<span style="border: 1px solid green;">0 0.3901003133505583</span>
<span style="border: 1px solid green;">1 0.19187432969920337</span>
<span style="border: 1px solid green;">2 0.0640524192713201</span>
<p>0 1</p>
<p>1 2</p>
<p>2 3</p>
<p>3 4</p>
<p>4 5</p>
<div>
hello
<br>
world
</div>
<section>ololo</section>
<p>
0 9
<div>0</div>
<div>1</div>
<div>0 9</div>
</p>
<p>
1 8
<div>0</div>
<div>1</div>
<div>1 8</div>
</p>
<p>
2 7
<div>0</div>
<div>1</div>
<div>2 7</div>
</p>
2222
Define custom actions
You can define custom actions for build process. For example, if you use
jQuery, you can define an action for event handlers binding like below:
$C.define('on', function(item, index, arr, args) {
$.fn.on.apply($(this), args);
});
$C(document.body)
.div()
.on('click', function(e) { alert(123); })
.on('mousemove', function(e) { alert(345); })
.text('I am clickable and mousemoveable')
.end(2);
Memorize results
On every step of DOM building, we can memorize nodes and other data. Memorized
items are being put into $C.mem dictionary. $C.mem dictionary is initially
empty, but it is shared between different $C() calls. You may want to reset
this dictionary manually like $C.mem = {}.
$C(document.body)
.div()
.mem('helloDiv')
.text('hello')
.end()
.each([11, 22])
.span()
.mem(function(item, index, arr) {
return 'each' + index;
}, function(item, index, arr) {
return index + ' ' + item + ' ' + this.tagName.toLowerCase();
})
.end()
.end()
.end();
In this example $C.mem will be:
{helloDiv: <div>​hello​</div>​, each0: '0 11 span', each1: '1 22 span'}
Another example (with $C.mem resetting):
$C.mem = {aa: 123, bb: 234};
$C(document.body)
.div()
.mem('aa')
.text('hello')
.end()
.end();
And $C.mem will be:
{aa: <div>​hello​</div>​, bb: 234}