supplant - Crockford

supplant.js

/**
* supplant() does variable substitution on the string. It scans through the string looking for 
* expressions enclosed in { } braces. If an expression is found, use it as a key on the object, 
* and if the key has a string value or number value, it is substituted for the bracket expression 
* and it repeats.
*
* Updated by Rob Taylor
* http://roboncode.com
* 
* Originally written by Douglas Crockford
* http://www.crockford.com/
*/
String.prototype.supplant = function (o, options) {
	var openTag = options ? options.openTag || '{' : '{';
	var closeTag = options ? options.closeTag || '}' : '}';
	return this.replace(
		new RegExp(openTag + '([^' + openTag + closeTag + ']*)' + closeTag, 'g'),
		function (a, b) {
			var r = o[b];
			return typeof r === 'string' || typeof r === 'number' ? r : a;
		}
	);
};

function supplant (str, o, options) {
	var openTag = options ? options.openTag || '{' : '{';
	var closeTag = options ? options.closeTag || '}' : '}';
	return str.replace(
		new RegExp(openTag + '([^' + openTag + closeTag + ']*)' + closeTag, 'g'),
		function (a, b) {
			var r = o[b];
			return typeof r === 'string' || typeof r === 'number' ? r : a;
		}
	);
}

//
// Example 1 basic usage
//
linkTpl = '<a href="{url}" class="{class}">{lable}</a>';

links = linkTpl.supplant({
	url : 'http://example.com',
	class : 'lnk',
    lable : 'Link Bezeichnung'
});

//
// Example 2 more advanced usage
//
var items = [],
    listItemTpl = '<li><a href="{url}" class="{class}">{lable}</a></li>';

for (i=0;i<20;i++) {
    items.push(listItemTpl.supplant({
       url : 'http://example.com',
       class : 'lnk',
       lable : 'Link Bezeichnung'
    }));   
}
// Join items e.g. to insert into DOM
items = items.join('');