textloader.js

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// Description: js.io.TextLoader 文本资源加载器,实现客户端的高速缓存
// Author:	Changhua.Wan
// Version:	2004.03.06.01


_package("js.lang");

_import("js.lang.Object");
_import("js.net.Encoder");

function js.io.TextLoader() {

	var cache = new function() {
		var _dict = new ActiveXObject("Scripting.Dictionary");
		this.get = function(_name) {
			if (!_dict.Exists(_name))
				return null;
			else
				return _dict.Item(_name);
		};
		this.put = function(_name, _value) {
			if (_dict.Exists(_name)) _dict.Item(_name) = _value;
			else _dict.Add(_name, _value);
		};
		this.remove = function(_name) {
			if (_dict.Exists(_name)) _dict.Remove(_name);
		};
	};

	this.load = function(_respath, _reload) {
		try {
			if (typeof(_reload) != "boolean") _reload = false;
			var _resname = _respath;
			var _res = null;
			if (_reload == true || null == (_res = cache.get(_resname))) {
				_res = this.loadResourceFromServer(_respath);
				if (_res != null)cache.put(_resname, _res);
			}
			return _res;
		} catch(ex) {
			_throw(ex);	
		}
	};

	this.loadResourceFromServer = function(_respath) {
		var xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
		xmlHttp.open("GET", _respath, false);
		xmlHttp.send();
		if (xmlHttp.status == 200 || xmlHttp.status == 0) {
			// 如果编码类型是 ASCII ，且含有中文必须进行编码
			// 如果编码类型是 UNICODE,UTF-8 直接 return(xmlHttp.responseText) 即可
			var _charset = js.net.Encoder.getCharset(xmlHttp.responseBody);
			if (_charset == "ASCII")
				return js.net.Encoder.ascToStr(xmlHttp.responseBody);
			else
				return xmlHttp.responseText;
		} else {
			_throw(0x0F04, "js.io.TextLoader/loadResourceFromServer():不能加载 "
					+ _respath
					+ " 资源 {HTTP-STATUS:"
					+ xmlHttp.status
					+"}"
				);
			return null;
		}
	};

}

var _p = js.io.TextLoader._extends("js.lang.Object");

var _c = js.io.TextLoader;

_c.defaultInstance = null;

_c.getInstance = function() {
	var _c = js.io.TextLoader;
	if (_c.defaultInstance == null) {
		_c.defaultInstance = new js.io.TextLoader();
	}
	return _c.defaultInstance;
}