/*
 * contentLoader.js
 *
 * Get the latest version from:
 *
 * http://www.jsclasses.org/fast-content-loader
 *
 * @(#) $Id: contentLoader.js,v 1.14 2011/03/11 06:56:59 mlemos Exp $
 *
 *
 * This LICENSE is in the BSD license style.
 * *
 * Copyright (c) 2010, Manuel Lemos
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 *   Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 *   Neither the name of Manuel Lemos nor the names of his contributors
 *   may be used to endorse or promote products derived from this software
 *   without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *  Portions of the code that implement document write capture are based
 *  on the Bezen library by Eric Brechemier licensed under the Creative
 *  Commons Attribution license 3.0:
 *
 *  http://creativecommons.org/licenses/by/3.0/ 
 *
 *  http://bezen.org/javascript/
 */

if(typeof(ML) === 'undefined')
	var ML = {};
if(typeof(ML.content) === 'undefined')
	ML.content = {};
ML.content.contentLoader = function()
{
	var doNotRemoveThisGetTheLatestVersionFrom = 'http://www.jsclasses.org/fast-content-loader',
		content = [],
		update = null;

	this.debug = false;
	this.defaultInline = false;
	this.updateInterval = 10;
	this.contentPrefix = 'con';
	this.delayedPrefix = 'del';
	this.delayedContent = ' ';

	var outputDebug = function(o, message)
	{
		if(o.debug)
		{
			if(console
			&& console.log)
				console.log(message);
			else
				alert(message);
		}
		return false;
	};

	var replaceContent = function(o)
	{
		var remaining = 0;

		for(var c in content)
		{
			if(!content[c].loaded)
			{
				var delayed = document.getElementById(content[c].delayed),
					place = document.getElementById(content[c].id);
				if(delayed
				&& place)
				{
					delayed.parentNode.removeChild(delayed);
					place.parentNode.replaceChild(delayed, place);
					delayed.style.display = (content[c].inline ? 'inline' : 'block');
					content[c].loaded = true;
				}
				else
					++remaining;
			}
		}
		if(remaining == 0)
		{
			window.clearInterval(update);
			update = null;
		}
		return remaining;
	};

	this.addContent = function(properties)
	{
		if(!properties.content)
			return outputDebug(this, 'Content properties are missing');
		properties.id = this.contentPrefix + content.length;
		properties.delayed = this.delayedPrefix + content.length;
		if(typeof(properties.inline) === 'undefined')
			properties.inline = this.defaultInline;
		properties.loaded = false;
		if(typeof properties.priority != 'number')
			properties.priority = 0;
		document.write('<div id="' + properties.id + '" style="' + (properties.width ? 'width: ' + properties.width + 'px;' : '') + (properties.height ? ' height: ' + properties.height + 'px;' : '') + ' overflow: none; display: ' + (properties.inline ? ((properties.width || properties.height) ? 'inline-block' : 'inline') : 'block') + '">' + this.delayedContent + '</div>');
		for(var i = content.length; i > 0 && content[i - 1].priority < properties.priority; --i);
		for(var m = content.length; m > i; --m)
			content[m] = content[m - 1];
		content[i] = properties;
		return true;
	};
	
	this.loadContent = function()
	{
		var o = this;

		if(window.opera
		|| navigator.userAgent.indexOf('MSIE') != -1)
		{
			var written = [];

			var write = function(html)
			{
				written.push(html);
			};

			var writeln = function(html)
			{
				write(html + "\n");
			};

			var reportError = function(error, url, line)
			{
				if(typeof error === 'object')
				{
					reportError(error.message, error.fileName, error.lineNumber);
					return;
				}
				outputDebug(o, error + ' at ' + url + '[' + line + ']');
			};
 
			var catchError = function(func, description)
			{
				description = description || 'error.catchError';

				if(typeof func !== 'function')
				{
					reportError(description + ': A function is expected, found ' + typeof func);
					return function() { };
				}

				return(function()
				{
					try
					{
						return func.apply(this,arguments);
					}
					catch(e)
					{
						if(window.onerror)
							window.onerror(description + ': ' + e.message + ' in ' + func, e.fileName, e.lineNumber, true);
					}
				});
			};

			var trim = function(text)
			{
				return(text.replace(/^\s*/, '').replace(/\s*$/, ''));
			};

			var hasAttribute = function(node, attribute)
			{
				if(node.hasAttribute)
					return node.hasAttribute(attribute);
 
				var attributeNode = node.getAttributeNode(attribute);

				if(attributeNode === null)
					return false;
				return attributeNode.specified;
			};

			var moveScript = function(script, target, callback)
			{
				var safeCallback = catchError(callback, 'script.onload');
 
				if(script.readyState
				&& script.onload !== null)
				{
					script.onreadystatechange = function()
					{
						if(script.readyState === 'loaded'
						|| script.readyState === 'complete')
						{
							script.onreadystatechange = null;
							script.onerror = null;
							safeCallback();
						}
					};
				}
				else
					script.onload = safeCallback;
				target.appendChild(script);
			};

			var moveScriptClone = function(script, target, callback)
			{
				if(hasAttribute(script, 'src'))
				{
					var externalScript = document.createElement('script'),
						i = 0;

					for (; i < script.attributes.length; ++i)
					{
						var attribute = script.attributes[i];

						if(hasAttribute(script, attribute.name))
							externalScript.setAttribute(attribute.name, attribute.value);
					}
					externalScript.text = script.text;
					moveScript(externalScript, target, callback);
				}
				else
				{
					var internalScript = script.cloneNode(false);

					internalScript.text = script.text;
					internalScript.type = 'any';
					target.appendChild(internalScript);
					if(hasAttribute(script, 'type'))
						internalScript.setAttribute('type', script.type);
					else
						internalScript.removeAttribute('type');

					var code = trim(internalScript.text);

					if(code.indexOf('<!--') === 0)
					{
						code = code.substr(4);
						if(code.substr(code.length - 3) === '-->')
							code = code.substr(0, code.length - 3);
					}
					(new Function(code))();
					callback();
				}
			};
 
			var moveNodes = function(source, target, callback)
			{
				if(source === null)
				{
					callback();
					return;
				}

				var nextSource = null,
					nextTarget = target;
				var nextStep = function()
				{
					moveNodes(nextSource, nextTarget, callback);
				};
 
				if(source.nodeName === 'SCRIPT'
				&& (!source.language
				|| source.language.toLowerCase() === 'javascript')
				&& (!source.type
				|| trim(source.type).toLowerCase() === 'text/javascript'))
				{
					setTimeout(function()
					{
						moveScriptClone(source, target, function()
						{
							insertWritten(target, nextStep);
						});
					}, 0);
				}
				else
				{
					var clone = source.cloneNode(false);

					target.appendChild(clone);
					setTimeout(nextStep, 0);
					if(source.firstChild)
					{
						var scriptCount = source.getElementsByTagName('script').length;
						if(scriptCount === 0)
						{
							if(source.nodeName === 'TABLE')
								clone.outerHTML = source.outerHTML;
							else
								clone.innerHTML = source.innerHTML;
						}
						else
						{
							nextSource = source.firstChild;
							nextTarget = clone;
						}
					}
				}
				if(nextSource === null)
					nextSource = source.nextSibling;
 
				var sourceAncestor = source.parentNode;

				while(nextSource === null
				&& sourceAncestor !== null)
				{
					nextSource = sourceAncestor.nextSibling;
					nextTarget = nextTarget.parentNode;
					sourceAncestor = sourceAncestor.parentNode;
				}
			};

			var insertWritten = function(target, callback)
			{
				if(written.length > 0)
				{
					var div = document.createElement('div');
					div.innerHTML = '<br>' + written.join('');
					written = [];
					div.removeChild(div.firstChild);
					moveNodes(div.firstChild, target, callback);
				}
				else
					callback();
			};

			var load = function()
			{
				var documentWrite = document.write,
					documentWriteln = document.writeln,
					c = 0;
				document.write = write;
				document.writeln = writeln;
				var loadContentElement = function (c)
				{
					var div = document.getElementById(content[c].id);
					div.innerHTML = '';
					write(content[c].content);
					insertWritten(div, function ()
					{
						content[c].loaded = true;
						++c;
						if(c < content.length)
							loadContentElement(c);
						else
						{
							document.writeln = documentWriteln;
							document.write = documentWrite;
						}
					});
				}
				loadContentElement(0);
			};

			if(content.length)
			{
				if(window.addEventListener)
					window.addEventListener('load', load, false);
				else
				{
					if(window.attachEvent)
						window.attachEvent('onload', load);
					else
					{
						if(document.addEventListener)
							document.addEventListener('load', load, false);
						else
							document.attachEvent('onload', load);
					}
				}
			}
		}
		else
		{
			for(var c in content)
			{
				if(!content[c].loaded)
					document.write('<div id="' + content[c].delayed + '" style="' + (content[c].width ? 'width: ' + content[c].width + 'px;' : '') + (content[c].height ? ' height: ' + content[c].height + 'px;' : '') + ' overflow: none; display: none">' + content[c].content + '</div>');
			}
			if(replaceContent(this)
			&& update == null)
			{
				update = window.setInterval(function()
				{
					replaceContent(o);
				}, this.updateInterval);
			}
		}
	};
}