cejs/application/net/Ajax.js

A JavaScript module framework that is simple to use.

/**
 * @name CeL function for Ajax (Asynchronous JavaScript and XML)
 * @fileoverview 本檔案包含了模擬WWW客戶端發送HTTP/HTTPS請求用的 functions。
 * @since 2015/1/1
 */

'use strict';
// 'use asm';

// --------------------------------------------------------------------------------------------

// 不採用 if 陳述式，可以避免 Eclipse JSDoc 與 format 多縮排一層。
typeof CeL === 'function' && CeL.run({
	// module name
	name : 'application.net.Ajax',

	// Promise for fetch()
	require : 'data.code.compatibility.'
	// library_namespace.copy_properties()
	+ '|data.native'
	// MIME_of()
	+ '|application.net.MIME.'
	// for CeL.to_file_name(), CeL.URI, CeL.Search_parameters
	+ '|application.net.',

	// 設定不匯出的子函式。
	// no_extend : '*',

	// 為了方便格式化程式碼，因此將 module 函式主體另外抽出。
	code : module_code
});

function module_code(library_namespace) {

	function time_message(millisecond) {
		if (library_namespace.age_of) {
			return library_namespace.age_of(0, millisecond, {
				digits : 1
			});
		}

		return millisecond % 1000 === 0 ? millisecond / 1000 + 's'
				: millisecond + 'ms';
	}

	// "Error: socket hang up" {code: 'ECONNRESET'}
	// "Error: connect ETIMEDOUT 1.1.1.1:80"
	// {errno:'ETIMEDOUT', code: 'ETIMEDOUT', address: '125.89.70.31', port:80 }
	// Error: connect ECONNREFUSED 127.0.0.1:443
	// "Error: read ECONNRESET"
	// {errno: 'ECONNRESET', code: 'ECONNRESET', syscall: 'read'}
	// Error: getaddrinfo ENOTFOUND domain
	// ERROR_BAD_STSTUS
	// Error: Timeout 30s
	function localize_error(error) {
		var message = String(error);
		if (library_namespace.gettext) {
			// 處理特別的錯誤訊息。
			var matched = message
					.match(/^(Error: (?:(?:connect|getaddrinfo) E[A-Z]+|Timeout) )(.+)$/);
			if (matched) {
				message = [ matched[1] + '%1', matched[2] ];
			}
			message = Array.isArray(message)
			// gettext_config:{"id":"error-connect-etimedout-$1","mark_type":"combination_message_id"}
			// gettext_config:{"id":"error-connect-econnrefused-$1","mark_type":"combination_message_id"}
			// gettext_config:{"id":"error-getaddrinfo-enotfound-$1","mark_type":"combination_message_id"}
			// gettext_config:{"id":"error-timeout-$1","mark_type":"combination_message_id"}
			? library_namespace.gettext.apply(null, message)
			// gettext_config:{"id":"error-socket-hang-up","mark_type":"combination_message_id"}
			// gettext_config:{"id":"error-read-econnreset","mark_type":"combination_message_id"}
			// gettext_config:{"id":"error-write-econnaborted","mark_type":"combination_message_id"}
			// gettext_config:{"id":"error-unexpected-end-of-file","mark_type":"combination_message_id"}
			: library_namespace.gettext(message);
		}
		return message;
	}

	var
	/** {Number}未發現之index。 const: 基本上與程式碼設計合一，僅表示名義，不可更改。(=== -1) */
	NOT_FOUND = ''.indexOf('_');

	/**
	 * null module constructor
	 * 
	 * @class web Ajax 的 functions
	 */
	var _// JSDT:_module_
	= function() {
		// null module constructor
	};

	/**
	 * for JSDT: 有 prototype 才會將之當作 Class
	 */
	_// JSDT:_module_
	.prototype = {};

	// ---------------------------------------------------------------------//
	// XMLHttp set ajax通信処理ライブラリ ==================

	/**
	 * <code>
	to use: include in front:
	way1(good: 以reg代替functionPath!):
	//		[function.js]_iF
	//		[function.js]End

	way2(old):
	//		[function.js]getU,functionPath,'eval(getU(functionPath));'
	//		[function.js]End

	old:
	function getU(p){var o;try{o=new ActiveXObject('Microsoft.XMLHTTP');}catch(e){o=new XMLHttpRequest();}if(o)with(o){open('GET',p,false),send(null);return responseText;}}
	</code>
	 */

	/**
	 * JScript or .wsh only, 能 encode.
	 * 
	 * @param {String}page_url
	 *            page url
	 * @param {String}[charset]
	 *            character encoding of HTML web page. e.g., 'UTF-8', big5,
	 *            euc-jp, ...
	 * @param POST_text
	 *            POST text
	 * 
	 * @returns {String}
	 * @see http://neural.cs.nthu.edu.tw/jang/books/asp/getWebPage.asp?title=10-1%20%E6%8A%93%E5%8F%96%E7%B6%B2%E9%A0%81%E8%B3%87%E6%96%99
	 */
	function get_page(page_url, charset, POST_text) {
		try {
			// may cause error
			var X = new ActiveXObject('Microsoft.XMLHTTP'), AS;
			X.open(POST_text ? 'POST' : 'GET', page_url, false);
			// POST need this
			X.setRequestHeader("Content-Type",
					"application/x-www-form-urlencoded");
			// Download the file
			X.send(POST_text || null);
			AS = new ActiveXObject("ADODB.Stream");
			// 可同時進行讀寫
			AS.Mode = 3;
			// 以二進位方式操作
			AS.Type = 1;
			// 開啟物件
			AS.Open();
			// 將 binary 的資料寫入物件內 may error
			AS.Write(X.responseBody);
			AS.Position = 0;
			// 以文字模式操作
			AS.Type = 2;
			// 設定編碼方式
			if (charset)
				AS.Charset = charset;
			// 將物件內的文字讀出
			X = AS.ReadText();
			// Release memory. 釋放被占用的記憶體.
			AS = null;
			return X;
		} catch (e) {
			library_namespace.warn('get_page: ' + e.message);
		}
	}

	// ---------------------------------------------------------------------//

	var KEY_URL = typeof Symbol === 'function' ? Symbol('URL')
			: '\0URL to fetch';

	/**
	 * 
	 * @param URL_to_fetch
	 * @param search
	 * @param hash
	 * @returns
	 * 
	 * @inner
	 */
	function set_parameters_and_hash(URL_to_fetch, search, hash) {
		// URL_to_fetch = library_namespace.URI(URL_to_fetch);
		// assert: library_namespace.is_URI(URL_to_fetch)
		if (hash || hash === '') {
			if (Object.defineProperty[KEY_not_native] && !/^#/.test(hash))
				hash = '#' + hash;
			URL_to_fetch.hash = hash;
		}
		URL_to_fetch.search_params.set_parameters(search);
		// console.trace(URL_to_fetch.toString(charset));
		return URL_to_fetch;
	}

	function normalize_URL_to_fetch(URL_to_fetch, charset, options) {
		// console.trace(URL_to_fetch);

		// https://developer.mozilla.org/en-US/docs/Web/API/URL
		// [ origin + pathname, search, hash ]
		// hrer = [].join('')
		if (Array.isArray(URL_to_fetch)) {
			URL_to_fetch = set_parameters_and_hash(library_namespace
					.URI(URL_to_fetch[0]), URL_to_fetch[1], URL_to_fetch[2]);
			if (charset)
				URL_to_fetch.charset = charset;
		} else {
			// 當輸入 {URL} 時，node_https.request() 會將 {URL} 轉成
			// {Object}options，不會考慮額外選項 (headers, ...)。
			// 且必須處理 charset，乾脆直接將 {URL} 轉成尋常 plain object / {URI}。
			// https://nodejs.org/api/http.html#http_http_request_url_options_callback
			// If url is a string, it is automatically parsed with new URL(). If
			// it is a URL object, it will be automatically converted to an
			// ordinary options object.

			// console.trace([ URL_to_fetch, charset ]);
			URL_to_fetch = library_namespace.URI(URL_to_fetch, null, {
				charset : charset
			});
			// console.trace(URL_to_fetch);
		}
		// assert: library_namespace.is_URI(URL_to_fetch)
		// console.trace(URL_to_fetch);

		if (options.search || options.hash) {
			URL_to_fetch = set_parameters_and_hash(URL_to_fetch,
					options.search, options.hash);
		}

		library_namespace.debug({
			T : [ 'Fetching URL: %1', '{' + (typeof URL_to_fetch) + '} ['
			//
			+ (typeof URL_to_fetch === 'string' ? URL_to_fetch
			//
			: URL_to_fetch && URL_to_fetch[KEY_URL]
			//
			|| URL_to_fetch.toString(charset)) + ']' ]
		}, 1, 'normalize_URL_to_fetch');

		return URL_to_fetch;
	}

	if (false)
		// default arguments
		var get_URL_arguments = {
			URL : '',
			charset : '',
			// HTTP方法，如"GET", "POST", HEAD, "PUT", "DELETE"等。
			method : 'GET',
			post_data : {},
			async : true,
			// user name. 驗證用使用者名稱。
			user : '',
			// 驗證用密碼。
			password : '',
			// header
			headers : {
				contentType : 'text/xml'
			},
			// location.search
			search : {
				contentType : 'text/xml'
			},
			// location.hash
			hash : '',
			mime : 'text/xml',
			// onreadystatechange
			onchange : function() {
			},
			timeout : 0,
			onfail : function(error) {
				this.status;
			},
			onload : function() {
			}
		};

	// XMLHttp.readyState 所有可能的值如下：
	// 0 還沒開始
	// 1 讀取中 Sending Data
	// 2 已讀取 Data Sent
	// 3 資訊交換中 interactive: getting data
	// 4 一切完成 Completed
	var readyState_done = 4,
	//
	document_head = library_namespace.is_WWW(true)
			&& (document.head || document.getElementsByTagName('head')[0]);

	/**
	 * 讀取 URL via XMLHttpRequest。
	 * 
	 * @param {String|Object}URL_to_fetch
	 *            欲請求之目的 URL or options
	 * @param {Function}[onload]
	 *            callback when successful loaded
	 * @param {String}[charset]
	 *            character encoding of HTML web page. e.g., 'UTF-8', big5,
	 *            euc-jp, ...
	 * @param {String|Object}[post_data]
	 *            text data to send when method is POST
	 * @param {Object}[options]
	 *            附加參數/設定選擇性/特殊功能與選項
	 * 
	 * TODO: 代理伺服器 using proxy server
	 * 
	 * @see https://developer.mozilla.org/zh-TW/docs/DOM/XMLHttpRequest
	 *      http://msdn.microsoft.com/en-us/library/ie/ms535874.aspx
	 */
	function get_URL(URL_to_fetch, onload, charset, post_data, options) {
		// 前導作業。
		if (library_namespace.is_Object(charset) && !options) {
			options = post_data;
			post_data = charset;
			charset = null;
		}
		// 正規化並提供可隨意改變的同內容參數，以避免修改或覆蓋附加參數。
		options = library_namespace.new_options(options);

		// ------------------------------------------------------

		if (library_namespace.is_Object(URL_to_fetch) && URL_to_fetch[KEY_URL]) {
			Object.assign(options, URL_to_fetch);
			// 注意: options.onload 另有用途!
			// https://xhr.spec.whatwg.org/#handler-xhr-onloadstart
			// onload = options.onload || onload;
			post_data = options.post || post_data;
			charset = options.charset || charset;
			URL_to_fetch = options[KEY_URL];
		}

		URL_to_fetch = normalize_URL_to_fetch(URL_to_fetch, charset, options);
		// assert: library_namespace.is_URI(URL_to_fetch)

		if (typeof onload === 'object') {
			library_namespace.debug(
					'Trying to JSONP, insert page, need callback.', 3,
					'get_URL');
			// library_namespace.run(URL_to_fetch);
			for ( var callback_param in onload) {
				library_namespace.debug('Trying ('
						+ (typeof onload[callback_param]) + ') ['
						+ callback_param + '] = [' + onload[callback_param]
						+ ']', 3, 'get_URL');
				if (callback_param
						&& typeof onload[callback_param] === 'function') {
					var callback_name, node = document.createElement('script');
					for (charset = 0; (callback_name = 'cb' + charset) in library_namespace;)
						charset++;
					library_namespace[callback_name] = function(data) {
						library_namespace.debug('[' + URL_to_fetch
								+ ']: callback 完自動移除 .js。', 2, 'get_URL');
						document_head.removeChild(node);
						// Release memory. 釋放被占用的記憶體.
						node = null;
						delete library_namespace[callback_name];
						onload[callback_param](data);
					};
					// callback_param: callback parameter
					URL_to_fetch.search_params[callback_param] = library_namespace.Class
							+ '.' + callback_name;
					node.src = URL_to_fetch.toString();
					library_namespace.debug('Use script node: [' + node.src
							+ ']', 3, 'get_URL');
					document_head.appendChild(node);
					return;
				}
			}
			library_namespace.debug('Skip JSONP. No callback specified.', 3,
					'get_URL');
		}

		if (post_data && !options.form_data) {
			post_data = library_namespace.Search_parameters(post_data)
					.toString(charset);
		}

		if (!onload && typeof options.onchange === 'function') {
			onload = function() {
				options.onchange(readyState_done, XMLHttp);
			};
		}

		if (options.async === false && onload || typeof onload !== 'function') {
			onload = false;
		}

		/**
		 * The XMLHttpRequest object can't be cached.
		 */
		var XMLHttp = library_namespace.new_XMLHttp();

		try {
			// IE:404 會 throw error, timeout 除了 throw error,
			// 還會 readystatechange;
			// Gecko 亦會 throw error
			// IE 10 中，local file 光 .open() 就 throw 了。
			XMLHttp.open(options.method || (post_data ? 'POST' : 'GET'),
					URL_to_fetch.toString(), !!onload, options.user || '',
					options.password || '');

			// https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/response
			// XMLHttp.responseType = 'blob';

			if (options.timeout > 0 && !onload) {
				// https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/timeout
				XMLHttp.timeout = options.timeout;
				if (typeof options.onfail === 'function')
					XMLHttp.ontimeout = function(e) {
						options.onfail.call(XMLHttp, e || 'Timeout');
					};
			}
			// TODO: 處理有 onload 下之 timeout 逾時ms數
			// Ajax 程式應該考慮到 server 沒有回應時之處置

			if (library_namespace.is_Object(options.headers)
			// https://developer.mozilla.org/zh-TW/docs/Web/API/XMLHttpRequest/setRequestHeader
			// `!!XMLHttp.setRequestHeader` will throw @ HTA (HTML Application)
			&& ('setRequestHeader' in XMLHttp)) {
				Object.keys(options.headers).forEach(function(key) {
					XMLHttp.setRequestHeader(key, options.headers[key]);
				});
			}

			if (options.mime) {
				// ignore charset!
				charset = options.mime;
			} else if (charset) {
				// old: 'text/xml;charset=' + charset
				// 但這樣會被當作 XML 解析，產生語法錯誤。
				// TODO: try:
				// 'text/'+(/\.x(ht)?ml$/i.test(URL_to_fetch)?'xml':'plain')+';charset='
				// + charset;
				charset = 'application/json;charset=' + charset;
			}

			// 有些版本的 Mozilla 瀏覽器在伺服器送回的資料未含 XML mime-type
			// 檔頭（header）時會出錯。為了避免這個問題，可以用下列方法覆寫伺服器傳回的檔頭，以免傳回的不是 text/xml。
			// http://squio.nl/blog/2006/06/27/xmlhttprequest-and-character-encoding/
			// http://www.w3.org/TR/XMLHttpRequest/ search encoding
			if (charset && XMLHttp.overrideMimeType)
				XMLHttp.overrideMimeType(charset);

			if (onload) {
				XMLHttp.onreadystatechange = function() {
					if (XMLHttp.readyState === readyState_done)
						return onload(XMLHttp);

					if (0 < XMLHttp.readyState
							&& XMLHttp.readyState < readyState_done) {
						if (typeof options.onchange === 'function')
							options.onchange(XMLHttp.readyState, XMLHttp);
					} else if (typeof options.onfail === 'function') {
						options.onfail(XMLHttp);
					}
				};
			}

			// 若檔案不存在，會 throw。
			XMLHttp.send(post_data || null);

			if (!onload) {
				// XMLHttp.response blob
				// XMLHttp.responseText 會把傳回值當字串用
				// XMLHttp.responseXML 會把傳回值視為 XMLDocument 物件，而後可用 JavaScript
				// DOM 相關函式處理
				// IE only(?):
				// XMLHttp.responseBody 以unsigned array格式表示binary data
				// try{responseBody=(new
				// VBArray(XMLHttp.responseBody)).toArray();}catch(e){}
				// http://aspdotnet.cnblogs.com/archive/2005/11/30/287481.html
				// XMLHttp.responseStream return AdoStream
				return XMLHttp.responseText;
			}

		} catch (e) {
			library_namespace.error(e);
			if (typeof options.onfail === 'function') {
				options.onfail(XMLHttp, e);
			} else if (onload) {
				onload(undefined, e);
			}
		}

	}

	_.get_URL = get_URL;

	// TODO: 處理 multiple requests
	function get_URLs() {
	}

	// ----------------------------------------------------

	var is_nodejs = library_namespace.platform.nodejs;

	/**
	 * <code>

	// "file": keyword for "Content-Disposition: file;"
	{type:'jpg',image:{file:'fn1.jpg'}}

	// will fetch url first.
	{type:'jpg',image:{url:'http://host/'}}

	{type:'jpg',image:{file:'fn1.jpg',type:'image/jpeg'}}

	// Array: use "Content-Type: multipart/mixed;"
	{type:'jpg',images:[{file:'fn1.jpg'},{file:'fn2.jpg'}]}

	{type:'jpg',images:[{file:'fn1.jpg'},{file:'fn2.jpg'}],docs:[{file:'fn1.txt'},{file:'fn2.txt'}]}

	{type:'jpg',images:[{file:'fn1.jpg',type:'image/jpeg'},{file:'fn1.txt',type:'text/plain'}]}

	</code>
	 */

	// should be CRLF
	// @see https://tools.ietf.org/html/rfc7578#section-4.1
	var form_data_new_line = '\r\n';

	function form_data_to_Array(is_slice) {
		if (this.generated) {
			return this.generated;
		}

		var boundary = '--' + this.boundary + form_data_new_line,
		// generated raw post data
		generated = this.generated = [ boundary ], content_length = boundary.length;
		boundary = form_data_new_line + boundary;
		this.forEach(function(chunk, index) {
			if (Array.isArray(chunk)) {
				// chunk = chunk.to_Array(true);
				if (!chunk.content_length) {
					console.log(chunk);
					throw new Error(
					// gettext_config:{"id":"the-chunk-do-not-has-regular-.content_length"}
					'The chunk do not has regular .content_length!');
				}
				content_length += chunk.content_length;
			} else {
				// chunk: {String} or {Buffer}
				content_length += chunk.length;
			}
			generated.push(chunk);
			if (index < this.length - 1) {
				generated.push(boundary);
				content_length += boundary.length;
			}
		}, this);

		if (!(content_length > 0)) {
			console.log(this);
			// gettext_config:{"id":"illegal-chunk.content_length"}
			throw new Error('Illegal chunk.content_length!');
		}

		boundary = form_data_new_line + '--' + this.boundary;
		if (!is_slice) {
			boundary += '--';
		}
		generated.push(boundary);
		content_length += boundary.length;

		generated.content_length = content_length;
		// console.log(generated);
		return generated;
	}

	// 選出 data.generated 不包含之 string
	function give_boundary(data_Array) {
		function not_includes_in(item) {
			// console.trace([ typeof item, item ]);
			return Array.isArray(item) ? item.every(not_includes_in)
			// item: Should be {String} or {Buffer}
			: !item.includes(boundary);
		}

		var boundary, retry_count = 0;
		while (retry_count++ < 8) {
			boundary = (Number.MAX_SAFE_INTEGER * Math.random())
					.toString(10 + 26);
			// console.log('test boundary: [' + boundary + ']');
			for (var i = 1; i < boundary.length / 2 | 0; i++) {
				var slice = boundary.slice(0, i);
				if (boundary.lastIndexOf(slice) > 0) {
					boundary = null;
					break;
				}
			}
			// assert: boundary 不自包含，例如 'aa'自包含'a'，'asas'自包含'as'
			if (boundary) {
				if (not_includes_in(data_Array)) {
					data_Array.boundary = boundary;
					return boundary;
				}
			}
		}
		throw new Error('give_boundary: '
		// gettext_config:{"id":"retry-too-many-times"}
		+ 'Retry too many times!');
	}

	var to_form_data_generated = {
		form_data_generated : true
	};

	// https://github.com/form-data/form-data/blob/master/lib/form_data.js
	// https://www.w3.org/TR/html401/interact/forms.html#h-17.13.4.2
	// https://tools.ietf.org/html/rfc7578
	// https://tools.ietf.org/html/rfc2046#section-5.1
	// The "multipart" boundary delimiters and header fields are always
	// represented as 7bit US-ASCII
	// https://tools.ietf.org/html/rfc2049#appendix-A
	// http://stackoverflow.com/questions/4238809/example-of-multipart-form-data
	function to_form_data(parameters, callback, options) {
		function get_file_object(value, callback, key, slice) {
			var is_url, MIME_type;
			if (typeof value === 'string') {
				is_url = value.includes('://');

			} else
			// else: assert: library_namespace.is_Object(value)
			if (is_url = value.url) {
				value = is_url;
				// is_url = true;
			} else {
				// .type: MIME type
				MIME_type = value.type;
				// value: file_path
				value = value.file;
			}

			function push_and_callback(MIME_type, content) {
				// https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Disposition
				var headers = 'Content-Disposition: '
						+ (slice ? 'file' : 'form-data; name="' + key + '"')
						+ '; filename="' + encodeURIComponent(value) + '"'
						+ "; filename*=UTF-8''" + encodeURIComponent(value)
						+ form_data_new_line;
				if (MIME_type) {
					headers += 'Content-Type: ' + MIME_type
							+ form_data_new_line;
				}
				if (is_nodejs && Buffer.isBuffer(content)) {
					headers += 'Content-Transfer-Encoding: binary'
							+ form_data_new_line;
				}
				headers += form_data_new_line;
				var chunk = [ headers, content ];
				// 手動設定 Content-Length。
				chunk.content_length = headers.length + content.length;
				// TODO: use stream
				(slice || root_data).push(chunk);
				callback();
			}

			if (!is_url) {
				var content;
				// read file contents
				if (is_nodejs) {
					try {
						// get {Buffer}
						content = node_fs.readFileSync(value);
					} catch (e) {
						// When we cannot read, it will throw now.
						// e.g., Error: ENOENT: no such file or directory, open
						// 'value'
					}
				} else {
					// node.js 之下此方法不能處理 binary data。
					content = library_namespace
							.get_file(value/* , 'binary' */);
				}
				if (!content) {
					library_namespace.error([ 'to_form_data: ', {
						// gettext_config:{"id":"failed-to-get-file-$1"}
						T : [ 'Failed to get file: [%1]', value ]
					} ]);
					// Skip this one.
					callback();
					return;
				}

				if (options && options.file_post_processor) {
					options.file_post_processor(value, content);
				}
				// value: file path → file name
				value = value.match(/[^\\\/]*$/)[0];
				if (!MIME_type) {
					MIME_type = library_namespace.MIME_of(value);
				}
				push_and_callback(MIME_type, content);
				return;
			}

			library_namespace.debug({
				// gettext_config:{"id":"fetching-url-$1"}
				T : [ '自網路取得 URL：%1', value ]
			}, 1, 'to_form_data');
			_.get_URL(value, function(XMLHttp, error) {
				if (options && options.url_post_processor) {
					options.url_post_processor(value, XMLHttp, error);
				}
				if (error) {
					library_namespace.error([ 'to_form_data: ', {
						// gettext_config:{"id":"got-error-when-retrieving-$1-$2"}
						T : [ 'Got error when retrieving [%1]: %2',
						//
						value, localize_error(error) ]
					} ]);
					// Skip this one.
					callback();
					return;
				}

				// value: url → file name
				value = value.replace(/[?#].*$/, '')
						.match(/([^\\\/]*)[\\\/]?$/)[1];
				// console.log('-'.repeat(79));
				// console.log(value);

				library_namespace.debug({
					// gettext_config:{"id":"got-url-from-the-network-$1-$2-bytes"}
					T : [ '自網路取得 URL：%1，%2{{PLURAL:%2|位元組}}。', value,
							XMLHttp.buffer.length ]
				}, 1, 'to_form_data');
				push_and_callback(XMLHttp.type, XMLHttp.buffer);
			}, 'buffer');
		}

		parameters = library_namespace.Search_parameters(parameters);

		var root_data = [], keys = Object.keys(parameters), index = 0;
		root_data.to_Array = form_data_to_Array;
		// console.log('-'.repeat(79));
		// console.log(keys);
		// 因為在遇到fetch url時需要等待，因此採用async。
		function process_next() {
			if (false) {
				console.log('-'.repeat(60));
				console.log('process_next: ' + index + '/' + keys.length);
				console.log(root_data);
			}

			if (index === keys.length) {
				// 決定 boundary
				give_boundary(root_data);
				// WARNING: 先結束作業: 生成 .to_Array()，
				// 才能得到 root_data.to_Array().content_length。
				root_data.to_Array();
				if (false) {
					console.log('-'.repeat(79));
					console.log(root_data);
					console.log('-'.repeat(79));
					console.log(root_data.to_Array().content_length);
					console.log(root_data.to_Array().join(''));
					throw 5;
				}
				callback(root_data);
				return;
			}

			var key = keys[index++], value = parameters[key];
			// console.log(key + ': ' + JSON.stringify(value));
			if (Array.isArray(value)) {
				// assert: is files/urls
				var slice = [], item_index = 0,
				//
				next_item = function() {
					if (item_index === value.length) {
						give_boundary(slice);
						var headers = 'Content-Disposition: form-data; name="'
								+ key + '"' + form_data_new_line
								+ 'Content-Type: multipart/mixed; boundary='
								+ slice.boundary + form_data_new_line
								+ form_data_new_line;
						slice = form_data_to_Array.call(slice, true);
						slice.unshift(headers);
						slice.content_length += headers.length;
						root_data.push(slice);
						process_next();
					} else {
						get_file_object(value[item_index++], next_item,/* key */
						undefined, slice);
					}
				};
				next_item();
				return;
			}

			if (library_namespace.is_Object(value)) {
				// assert: is file/url
				get_file_object(value, process_next, key);
				return;
			}

			// 預防有 null, undefined, {Number}, true 之類。
			if (!value || typeof value === 'number'
					|| typeof value === 'boolean') {
				value = String(value);
			}

			var headers;
			if (is_nodejs && typeof value === 'string') {
				value = Buffer.from(value, 'utf8');
				headers = 'Content-Type: text/plain; charset=UTF-8'
						+ form_data_new_line;
			}

			// 非檔案，屬於普通的表單資料。
			if (!key) {
				throw new Error('No key for value: ' + value);
			}
			if (!value && value !== '') {
				// e.g., token=undefined
				throw new TypeError('Invalid type of ' + key + ': '
						+ typeof value);
			}

			// @see function push_and_callback(MIME_type, content)
			headers = 'Content-Disposition: form-data; name="' + key + '"'
					+ form_data_new_line + (headers || '') + form_data_new_line;
			var chunk = [ headers, value ];
			// 手動設定 Content-Length。
			chunk.content_length = headers.length + value.length;
			root_data.push(chunk);
			process_next();
		}
		process_next();

		return root_data;
	}

	_.to_form_data = to_form_data;

	// ---------------------------------------------------------------------//

	/**
	 * <code>
		讀取URL by XMLHttpRequest
		http://jck11.pixnet.net/blog/post/11630232
	
	 * 若有多行程或為各URL設定個別XMLHttp之必要，請在一開始便設定deprecated_get_URL.multi_request，並且別再更改。
	 ** 在此情況下，單一URL仍只能有單一個request!
	 ** 設定 handle_function 須注意程式在等待回應時若無執行其他程式碼將自動中止！
		可設定：
		while(deprecated_get_URL.doing)WScript.Sleep(1);	//||timeout
	
	arguments f:{
		URL:'',	//	The same origin policy prevents document or script loaded from one origin, from getting or setting properties from a of a document from a different origin.(http://www.mozilla.org/projects/security/components/jssec.html#sameorigin)
		enc:'UTF-8',	//	charset: big5, euc-jp,..
		fn:(handle_function),	//	onLoad:function(){},
		method:'GET',	//	POST,..
		sendDoc:'text send in POST,..'
		async:ture/false,	//	true if want to asynchronous(非同期), false if synchronous(同期的,會直到readyState==4才return)	http://jpspan.sourceforge.net/wiki/doku.php?id=javascript:xmlhttprequest:behaviour
		user:'userName',
		passwd:'****',	//	password
	
	//TODO:
		parameters:'~=~&~=~', // {a:1,b:2}
		header:{contentType:'text/xml'},
		contentType:'text/xml',
		run:true/false,	//	do eval
		update:DOMDocument,	//	use onLoad/onFailed to 加工 return text. onFailed(){throw;} will abort change.
		interval:\d,
		decay:\d,	//	wait decay*interval when no change
		maxInterval::\d,
		//insertion:top/bottom,..
		onFailed:function(error){this.status;},	//	onFailed.apply(XMLHttp,[XMLHttp.status])
		onStateChange:function(){},
	}
	
	
	handle_function:
	自行處理	typeof handle_function=='function':
	function handle_function(error){..}
	代為處理	handle_function=[d_func,0: responseText,1: responseXML]:
	responseXML:	http://msdn2.microsoft.com/en-us/library/ms757878.aspx
	function d_func(content,headers[,XMLHttp,URL]){
		if(headers){
			//	content,headers各為XMLHttp.responseText內容及XMLHttp.getAllResponseHeaders()，其他皆可由XMLHttp取得。
		}else{
			//	content為error
		}
	}
	e.g., the simplest: [function(c,h){h&&alert(c);}]
	
	)
	</code>
	 */
	// (URL,fn) or flag URL, handle_function handle result,
	// method,sendDoc,asyncFlag,userName,password
	function deprecated_get_URL(f) {
		var _f = arguments.callee;
		if (typeof _f.XMLHttp === 'object') {
			// try{_f.XMLHttp.abort();}catch(e){}
			// 此時可能衝突或lose?!
			_f.XMLHttp = null;
		}
		// 處理 arguments
		if (!library_namespace.is_Object(f))
			a = arguments, f = {
				URL : f,
				fn : a[1],
				method : a[2],
				sendDoc : a[3]
			};
		if (f.post)
			f.method = 'POST', f.sendDoc = f.post;

		if (!f[KEY_URL]
				|| !(_f.XMLHttp = library_namespace.new_XMLHttp(f.enc,
						!/\.x(?:ht)?ml$/i.test(f[KEY_URL]))))
			// throw
			return;

		// try{_f.XMLHttp.overrideMimeType('text/xml');}catch(e){}
		if (typeof f.async !== 'boolean')
			// 設定f.async
			f.async = f.fn ? true : false;
		else if (!f.async)
			f.fn = null;
		else if (!f.fn)
			if (typeof _f.HandleStateChange !== 'function'
					|| typeof _f.HandleContent !== 'function')
				// 沒有能處理的function
				// throw
				return;
			else
				// =null;
				f.fn = _f.HandleContent;
		if (/* typeof _f.multi_request!=='undefined'&& */_f.multi_request) {
			if (!_f.q)
				// queue
				_f.i = {}, _f.q = [];
			// ** 沒有考慮到 POST 時 URL 相同的情況!
			_f.i[f[KEY_URL]] = _f.q.length;
			_f.q.push({
				uri : f[KEY_URL],
				XMLHttp : _f.XMLHttp,
				func : f.fn,
				start : _f.startTime = new Date
			});
		} else if (_f.q && typeof _f.clean === 'function')
			_f.clean();

		// for Gecko Error: uncaught exception: Permission denied to call method
		// XMLHttpRequest.open
		if (f[KEY_URL].indexOf('://') !== NOT_FOUND
				&& typeof netscape === 'object')
			if (_f.asked > 2) {
				_f.clean(f[KEY_URL]);
				return;
			} else
				try {
					if (typeof _f.asked === 'undefined') {
						_f.asked = 0;
						alert('我們需要一點權限來使用 XMLHttpRequest.open。\n* 請勾選記住這項設定的方格。');
					}
					netscape.security.PrivilegeManager
					// UniversalBrowserAccess
					.enablePrivilege('UniversalXPConnect');
				} catch (e) {
					_f.asked++;
					_f.clean(f[KEY_URL]);
					return;
				}

		// if(isNaN(_f.timeout))_f.timeout=300000;//5*60*1000;
		try {
			// IE:404會throw error, timeout除了throw error, 還會readystatechange;
			// Gecko亦會throw error
			try {
				_f.XMLHttp.setRequestHeader("Accept-Encoding",
						"gzip, deflate, br");
			} catch (e) {
			}
			// Set header so the called script knows that it's an XMLHttpRequest
			if (false)
				_f.XMLHttp.setRequestHeader("X-Requested-With",
						"XMLHttpRequest");
			// Set the If-Modified-Since header, if ifModified mode.
			if (false)
				_f.XMLHttp.setRequestHeader("If-Modified-Since",
						"Thu, 01 Jan 1970 00:00:00 GMT");
			if (f.method === 'POST'
			// &&_f.XMLHttp.setRequestHeader
			) {
				// use .getAttribute('method') to get 長度不一定如此
				if (false)
					_f.XMLHttp.setRequestHeader("Content-Length",
							f.sendDoc.length);
				// 有些CGI會用Content-Type測試是XMLHttp或是regular form
				// It may be necessary to specify
				// "application/x-www-form-urlencoded" or "multipart/form-data"
				// for posted XML data to be interpreted on the server.
				_f.XMLHttp.setRequestHeader('Content-Type', Array.isArray(f.fn)
						&& f.fn[1] ? 'text/xml'
				// application/x-www-form-urlencoded; charset=utf-8
				: 'application/x-www-form-urlencoded');
			}
			_f.XMLHttp.abort();
			_f.XMLHttp.open(f.method || 'GET', f[KEY_URL], f.async, f.user
					|| null, f.passwd || null);
			// alert((f.method||'GET')+','+f[KEY_URL]+','+f.async);
			/**
			 * @see http://www.javaworld.com.tw/jute/post/view?bid=49&id=170177&sty=3&age=0&tpg=1&ppg=1
			 *      根據 W3C的 XMLHttpRequest 規格書上說，①在呼叫 open
			 *      時，如果readyState是4(Loaded) ②呼叫abort之後
			 *      ③發生其他錯誤，如網路問題，無窮迴圈等等，則會重設所有的值。使用全域的情況就只有第一次可以執行，因為之後的readyState是4，所以onreadystatechange
			 *      放在open之前會被清空，因此，onreadystatechange 必須放在open之後就可以避免這個問題。
			 * 
			 * 每使用一次XMLHttpRequest，不管成功或失敗，都要重設onreadystatechange一次。onreadystatechange
			 * 的初始值是 null
			 * 
			 * @see http://www.xulplanet.com/references/objref/XMLHttpRequest.html
			 *      After the initial response, all event listeners will be
			 *      cleared. Call open() before setting new event listeners.
			 */
			if (f.async) {
				_f.doing = (_f.doing || 0) + 1;
				_f.XMLHttp.onreadystatechange = typeof f.fn === 'function'
				//
				? f.fn : function(e) {
					_f.HandleStateChange(e, f[KEY_URL], f.fn);
				}
				// ||null
				;
				// 應加 clearTimeout( )
				setTimeout('try{deprecated_get_URL.'
						//
						+ (_f.multi_request ? 'q[' + _f.i[f[KEY_URL]] + ']'
								: 'XMLHttp')
						+ '.onreadystatechange();}catch(e){}',
				// 5*60*1000;
				_f.timeout || 3e5);
			}
			_f.XMLHttp.send(f.sendDoc || null);
			if (!f.fn) {
				/**
				 * 非async(異步的)能在此就得到 response。Safari and Konqueror cannot
				 * understand the encoding of text files!
				 * 
				 * @see http://www.kawa.net/works/js/jkl/parsexml.html
				 */
				// responseXML: responseXML.loadXML(text)
				return _f.XMLHttp.responseText;
			}
		} catch (e) {
			if (typeof f.fn === 'function')
				f.fn(e);
			else if (typeof window === 'object')
				window.status = e.message;
			return e;
		}
	}
	deprecated_get_URL.timeoutCode = -7732147;

	/**
	 * agent handle function
	 * 
	 * e: object Error, handle_function: function(return text, headers,
	 * XMLHttpRequest object, URL) | [ function, (default|NULL:responseText,
	 * others:responseXML) ]
	 */
	deprecated_get_URL.HandleStateChange = function(e, URL, handle_function) {
		var _t = 0, isOKc, m = deprecated_get_URL.multi_request, _oXMLH;
		if (m)
			m = deprecated_get_URL.q[isNaN(URL) ? deprecated_get_URL.i[URL]
					: URL], _oXMLH = m.XMLHttp, handle_function = m.func,
					URL = m.uri;
		else
			_oXMLH = deprecated_get_URL.XMLHttp;
		if (Array.isArray(handle_function))
			_t = handle_function[1], handle_function = handle_function[0];
		if (!handle_function || typeof handle_function !== 'function') {
			deprecated_get_URL.doing--;
			deprecated_get_URL.clean(URL);
			return;
		}
		// http://big5.chinaz.com:88/book.chinaz.com/others/web/web/xml/index1/21.htm
		if (!e)
			if (typeof _oXMLH === 'object' && _oXMLH) {
				if (_oXMLH.parseError
						&& _oXMLH/* .responseXML */.parseError.errorCode !== 0)
					e = _oXMLH.parseError, e = new Error(e.errorCode, e.reason);
				else if (_oXMLH.readyState === 4) {
					// only if XMLHttp shows "loaded"

					// condition is OK?
					isOKc = _oXMLH.status;
					isOKc = isOKc >= 200
							&& isOKc < 300
							|| isOKc === 304
							|| !isOKc
							&& (location.protocol === "file:" || location.protocol === "chrome:");
					if (handle_function === deprecated_get_URL.HandleContent)
						// handle_function.apply()
						handle_function(0, isOKc, _oXMLH, URL);
					else {
						// handle_function.apply()
						handle_function(isOKc ? _t ? _oXMLH.responseXML
								// JKL.ParseXML: Safari and Konqueror cannot
								// understand the encoding of text files.
								: typeof window === 'object'
										&& window.navigator.appVersion
												.indexOf("KHTML") !== NOT_FOUND
										&& !(e = escape(_oXMLH.responseText))
												.indexOf("%u") !== NOT_FOUND
								//
								? e : _oXMLH.responseText : 0,
						//
						isOKc ? _oXMLH.getAllResponseHeaders() : 0, _oXMLH, URL);
					}
					// URL之protocol==file:
					// 可能需要重新.loadXML((.responseText+'').replace(/<\?xml[^?]*\?>/,""))
					// 用 .responseXML.documentElement 可調用
					deprecated_get_URL.doing--;
					deprecated_get_URL.clean(URL);
					return;
				}
			} else if (new Date - (m ? m.start : deprecated_get_URL.startTime) > deprecated_get_URL.timeout)
				// timeout & timeout function
				// http://www.stylusstudio.com/xmldev/199912/post40380.html
				// _oXMLH.abort();
				e = new Error(deprecated_get_URL.timeoutCode, 'Timeout');
		// alert(URL+'\n'+_t+'\n'+e+'\n'+_oXMLH.readyState+'\n'+handle_function);
		if (e) {
			handle_function(e, 0, _oXMLH, URL);
			deprecated_get_URL.doing--;
			deprecated_get_URL.clean(URL);
		}// handle_function.apply(e,URL);
	};

	/**
	 * agent content handle function<br />
	 * 有headers時content包含回應，否則content表error
	 */
	deprecated_get_URL.HandleContent = function(content, headers, _oXMLHttp,
			URL) {
		if (headers) {
			// _oXMLHttp.getResponseHeader("Content-Length")
			alert("URL:	" + URL + "\nHeaders:\n"
					+ _oXMLHttp.getAllResponseHeaders()
					+ "\n------------------------\nLastModified: "
					+ _oXMLHttp.getResponseHeader("Last-Modified")
					+ "\nResult:\n" + _oXMLHttp.responseText.slice(0, 200));// _oXMLHttp.responseXML.xml
		} else {
			// error
			// test時，可用deprecated_get_URL.XMLHttp.open("HEAD","_URL_",true);，deprecated_get_URL(url,handle_function,'HEAD',true)。
			if (content instanceof Error)
				alert('Error occured!\n'
						+ (typeof e === 'object' && e.number ? e.number + ':'
								+ e.message : e || ''));
			else if (typeof _oXMLHttp === 'object' && _oXMLHttp)
				alert((_oXMLHttp.status === 404 ? "URL doesn't exist!"
						: 'Error occured!')
						+ '\n\nStatus: '
						+ _oXMLHttp.status
						+ '\n'
						+ _oXMLHttp.statusText);
		}
	};

	// 在MP模式下清乾淨queue
	deprecated_get_URL.clean = function(i, force) {
		// multiple requests
		if (force || deprecated_get_URL.multi_request)
			if (!i && isNaN(i)) {
				if (deprecated_get_URL.q)
					for (i in deprecated_get_URL.i)
						try {
							deprecated_get_URL.q[deprecated_get_URL.i[i]].XMLHttp
									.abort();
							// deprecated_get_URL.q[deprecated_get_URL.i[i]].XMLHttp=null;
						} catch (e) {
						}
				deprecated_get_URL.q = deprecated_get_URL.i
				// =null
				= 0;
			} else if (!isNaN(i)
					|| !isNaN(i = deprecated_get_URL.i[typeof i === 'object' ? i.uri
							: i])) {
				try {
					deprecated_get_URL.q[i].XMLHttp.abort();
				} catch (e) {
				}

				// deprecated_get_URL.q[i].XMLHttp=0;
				delete deprecated_get_URL.i[deprecated_get_URL.q[i].uri];
				deprecated_get_URL.q[i] = 0;
			}
	};

	// ↑XMLHttp set ==================
	// ---------------------------------------------------------------------//

	// @see https://github.com/request/request

	var node_url, node_http, node_http2, node_https,
	// reuse the sockets (keep-alive connection).
	node_http_agent, node_http2_agent, node_https_agent,
	//
	node_zlib;

	/**
	 * 快速 merge cookie: 只檢查若沒有重複的 key，則直接加入。不檢查 path 也不處理 expires, domain,
	 * secure。<br />
	 * 為增加效率，不檢查 agent.last_cookie 本身之重複的 cookie。
	 * 
	 * TODO: create class Cookie, Cookie.prototype.merge(),
	 * Cookie.prototype.clone()
	 * 
	 * @param {Object}agent
	 *            node_http_agent / node_https_agent
	 * @param {Array}cookie
	 *            new cookie to merge
	 * 
	 * @returns {Object}agent.last_cookie
	 * 
	 * @inner
	 */
	function merge_cookie(agent, cookie) {
		// 初始化 initialization + 正規化 normalization
		var last_cookie = agent.last_cookie;
		if (!Array.isArray(last_cookie)) {
			last_cookie = agent.last_cookie = agent.last_cookie ? [ agent.last_cookie ]
					: [];
		}
		if (!cookie) {
			cookie = [];
		} else if (typeof cookie === 'string') {
			cookie = cookie.split(';');
		}
		// assert: Array.isArray(cookie)

		// console.log(agent);
		// console.log(last_cookie.cookie_hash);
		// console.trace(cookie);

		// cookie_index_of[key] = index of last_cookie
		var cookie_index_of = last_cookie.cookie_index_of;
		if (!cookie_index_of) {
			if (last_cookie.length > 0) {
				// regenerate agent.last_cookie
				delete agent.last_cookie;
				last_cookie = merge_cookie(agent, last_cookie);
				// assert: last_cookie === agent.last_cookie
			} else {
				last_cookie.cookie_index_of = Object.create(null);
				last_cookie.cookie_hash = Object.create(null);
			}
			cookie_index_of = last_cookie.cookie_index_of;
		}
		var cookie_hash = last_cookie.cookie_hash;
		// assert: !!cookie_hash === true

		cookie.forEach(function for_each_cookie_piece(piece) {
			piece = piece.trim();
			if (!piece)
				return;
			// [ cookie value without path / domain / expires,
			// key, value, extra ]
			var matched = piece.match(/^([^=;]+)(?:=([^;]+))?(.*)$/);
			library_namespace.debug('last_cookie: ' + last_cookie, 3,
					'merge_cookie');
			// console.log(matched);
			var key, value;
			if (matched) {
				key = matched[1];
				value = matched[2];

			} else {
				library_namespace.warn([ 'merge_cookie: ', {
					// gettext_config:{"id":"invalid-cookie"}
					T : 'Invalid cookie?'
				}, ' [' + piece + ']' ]);
				// treat cookie piece as key
				key = piece;
				value = '';
			}

			if (!key)
				return;

			cookie_hash[key] = value;

			if (key in cookie_index_of) {
				// assert: (key in cookie_hash) === true
				library_namespace.debug([ {
					// gettext_config:{"id":"duplicate-cookie-name!-the-later-newcomer-will-prevail"}
					T : 'cookie 名稱重複！以後來/新出現者為準。'
				}, ' [' + last_cookie[cookie_index_of[key]]
				//
				+ ']→[' + piece + ']' ], 3, 'merge_cookie');
				// remove duplicate cookie: 直接取代。
				last_cookie[cookie_index_of[key]] = piece;

			} else {
				// assert: (key in cookie_hash) === false
				library_namespace.debug([ {
					T : '正常情況。登記已存在之 cookie。'
				} ], 3, 'merge_cookie');
				// console.trace(matched);
				cookie_index_of[key] = last_cookie.length;
				last_cookie.push(piece);
			}
		});

		// console.trace(cookie_hash);
		// console.trace(last_cookie);

		library_namespace.debug('array: ' + JSON.stringify(last_cookie), 3,
				'merge_cookie');
		library_namespace.debug('hash: ' + JSON.stringify(cookie_hash), 3,
				'merge_cookie');
		return last_cookie;
	}

	_.merge_cookie = merge_cookie;

	function set_cookie_to_URL_object(URL_options_to_fetch, agent) {
		// console.trace('agent.last_cookie:');
		// console.log(agent.last_cookie);
		if (agent.last_cookie) {
			// 使用 cookie
			library_namespace.debug('agent.last_cookie: '
					+ JSON.stringify(agent.last_cookie), 3,
					'set_cookie_to_URL_object');
			library_namespace.debug('agent.last_cookie.cookie_hash: '
					+ JSON.stringify(agent.last_cookie.cookie_hash), 3,
					'set_cookie_to_URL_object');
			var cookie = (URL_options_to_fetch.headers.Cookie ? URL_options_to_fetch.headers.Cookie
					+ ';'
					: '')
					// cookie is Array @ Wikipedia
					+ (Array.isArray(agent.last_cookie) ? agent.last_cookie
					// 去掉 expires=...; path=/; domain=...; HttpOnly
					// 這個動作不做也可以，不影響結果。
					.map(function(cookie) {
						return cookie.replace(/;.*/, '');
					}).join('; ') : agent.last_cookie);
			if (cookie) {
				URL_options_to_fetch.headers.Cookie = cookie;
			} else {
				delete URL_options_to_fetch.headers.Cookie;
			}
		}
		library_namespace.debug('Set cookie: '
				+ JSON.stringify(URL_options_to_fetch.headers.Cookie), 3,
				'set_cookie_to_URL_object');
		library_namespace.debug('Set protocol: '
				+ URL_options_to_fetch.protocol, 3, 'set_cookie_to_URL_object');
		library_namespace.debug('Set headers: '
				+ JSON.stringify(URL_options_to_fetch.headers), 3,
				'set_cookie_to_URL_object');
	}

	// ---------------------------------------------------------------------//

	// 正處理中之 connections
	var get_URL_node_connections = 0,
	// 所有 requests
	get_URL_node_requests = 0;

	// 強制使用POST傳送。
	var FORCE_POST = {
		FORCE_POST : true
	};

	var ERROR_BAD_STSTUS = 'BAD STATUS';

	var KEY_not_native = library_namespace.env.not_native_keyword;
	var has_native_URL = typeof URL === "function" && !URL[KEY_not_native];

	/**
	 * 讀取 URL via node http/https。<br />
	 * assert: arguments 必須與 get_URL() 相容！
	 * 
	 * @param {String|Object}URL_to_fetch
	 *            欲請求之目的 URL or options
	 * @param {Function}[onload]
	 *            callback when successful loaded. For failure handling, using
	 *            options.onfail(error);
	 * @param {String}[charset]
	 *            character encoding of HTML web page. e.g., 'UTF-8', big5,
	 *            euc-jp,..
	 * @param {String|Object}[post_data]
	 *            text data to send when method is POST
	 * @param {Object}[options]
	 *            附加參數/設定選擇性/特殊功能與選項
	 * 
	 * @see https://nodejs.org/api/http.html#http_http_request_options_callback
	 *      https://nodejs.org/api/https.html#https_https_request_options_callback
	 * 
	 * @since 2015/1/13 23:23:38
	 */
	function get_URL_node(URL_to_fetch, onload, charset, post_data, options) {
		if (!URL_to_fetch) {
			onload(undefined, new SyntaxError('No URL input.'));
			return;
		}

		get_URL_node_requests++;
		if (get_URL_node_connections >= get_URL_node.connects_limit) {
			library_namespace.debug({
				// gettext_config:{"id":"waiting-$1-$2-connections-$3"}
				T : [ 'Waiting %1/%2 {{PLURAL:%1|connection|connections}}: %3',
				// 避免同時開過多 connections 的機制。
				get_URL_node_connections, get_URL_node_requests,
						String(URL_to_fetch) ]
			}, 3, 'get_URL_node');
			var _arguments = arguments;
			setTimeout(function() {
				get_URL_node_requests--;
				get_URL_node.apply(null, _arguments);
			}, 500);
			return;
		}
		// 進入 request 程序
		get_URL_node_connections++;

		// 前導作業。
		if (library_namespace.is_Object(charset) && !options) {
			options = post_data;
			post_data = charset;
			charset = null;
		}
		// 正規化並提供可隨意改變的同內容參數，以避免修改或覆蓋附加參數。
		options = library_namespace.new_options(options);

		// console.log('-'.repeat(79));
		// console.log(JSON.stringify(options));
		// console.log(options.form_data);
		if (options.form_data && options.form_data !== to_form_data_generated) {
			// console.trace(options);
			// TODO: charset for post_data
			to_form_data(post_data, function(data) {
				if (false) {
					console.log('>> '
					// library_namespace.data.code.string_digest()
					+ library_namespace.string_digest(data.toString(), 200));
				}
				options.form_data = to_form_data_generated;
				get_URL_node(URL_to_fetch, onload, charset, data, options);
			}, options.form_data);
			return;
		}

		// ------------------------------------------------------

		if (library_namespace.is_Object(URL_to_fetch) && URL_to_fetch[KEY_URL]) {
			Object.assign(options, URL_to_fetch);
			// 注意: options.onload 另有用途!
			// https://xhr.spec.whatwg.org/#handler-xhr-onloadstart
			// onload = options.onload || onload;
			post_data = options.post || post_data;
			charset = options.charset || charset;
			URL_to_fetch = options[KEY_URL];
		}

		// 不改變 options。
		var agent = options.agent;
		if (typeof URL_to_fetch === 'string' && URL_to_fetch.startsWith('//')) {
			// 處理 '//domain.org/path' 的情況。
			URL_to_fetch = (agent && agent.protocol || 'https:') + URL_to_fetch;
		}

		var URL_options_to_fetch = normalize_URL_to_fetch(URL_to_fetch,
				charset, options);
		// assert: library_namespace.is_URI(URL_options_to_fetch)
		// console.trace([ URL_to_fetch, URL_options_to_fetch ]);

		if (typeof onload === 'object') {
			library_namespace.debug(
					'Trying to JSONP, insert page, need callback.', 3,
					'get_URL_node');
			// library_namespace.run(URL_options_to_fetch);
			for ( var callback_param in onload) {
				if (callback_param
						&& typeof onload[callback_param] === 'function') {
					// 模擬 callback。
					// callback_param: callback parameter
					URL_options_to_fetch.search_params[callback_param] = 'cb';
					onload = onload[callback_param];
					break;
				}
			}
		}

		// assert: 自此開始不會改變 URL，也不會中途 exit 本函數。

		if (post_data && !options.form_data) {
			if (library_namespace.is_Object(post_data)
					&& options.headers
					&& typeof options.headers['Content-Type'] === 'string'
					&& options.headers['Content-Type']
							.includes('application/json')) {
				post_data = JSON.stringify(post_data) || FORCE_POST;

			} else {
				post_data = library_namespace.Search_parameters(post_data)
						.toString(options.post_data_charset || charset)
						|| FORCE_POST;
			}
		}

		if (!onload && typeof options.onchange === 'function') {
			onload = function() {
				options.onchange(readyState_done);
			};
		}

		if (options.async === false && onload || typeof onload !== 'function') {
			onload = false;
		}

		// console.trace(URL_options_to_fetch);
		// node_http.request(options): options needs a .path
		// https://nodejs.org/dist/latest/docs/api/http.html#http_http_request_options_callback
		URL_options_to_fetch.path = URL_options_to_fetch.pathname
				+ URL_options_to_fetch.search;

		var URL_is_https = /^https:?$/i.test(URL_options_to_fetch.protocol);

		// console.trace([ URL_to_fetch, URL_options_to_fetch.toString() ]);
		URL_to_fetch = URL_options_to_fetch.toString();
		// assert: {String}URL_to_fetch,
		// library_namespace.is_URI(URL_options_to_fetch)

		/**
		 * https://stackoverflow.com/questions/53593182/client-network-socket-disconnected-before-secure-tls-connection-was-established
		 * mh160.js 必須使用 request，https-proxy-agent 才能正常工作 TODO:
		 * socks-proxy-agent
		 * 
		 * <code>

		// https://techcult.com/free-proxy-software-for-windows-10/#1_Ultrasurf
		> SET http_proxy=http://127.0.0.1:9666
		> node u17.js 镇魂街

		</code>
		 */

		/**
		 * <code>

		// http://anonproxyserver.sourceforge.net/
		// https://www.proxynova.com/proxy-server-list/country-tw/
		var http = require("http");
		var options = {
			host: "211.22.233.69",
			port: 3128,
			path: "http://dict.revised.moe.edu.tw/cgi-bin/cbdic/gsweb.cgi?ccd=9gW4am&o=e0&sec=sec11&option=linkout001&actice=layout",
			//method: 'GET',
			headers: {
				Host: "dict.revised.moe.edu.tw"
			}
		};
		var request=http.request(options, function(response) {
			console.log(response.statusCode);
			console.log(response.headers);
			var data = [], length = 0;
			response.on('data', function(chunk) {length += chunk.length;data.push(chunk);});
			response.on('end', function() {data = Buffer.concat(data, length);console.log(data+'')});
		});
		request.end();



		require('./work_crawler_loader.js'); var PROXY='localhost:8080';

		CeL.get_URL('https://zh.wikipedia.org/wiki/Special:%E6%9C%80%E8%BF%91%E6%9B%B4%E6%94%B9',function(X){console.log(X.responseText)},null,null,{proxy:PROXY});
		CeL.get_URL('https://zh.wikipedia.org/wiki/Special:%E6%9C%80%E8%BF%91%E6%9B%B4%E6%94%B9',function(X){console.log(X.responseText)});

		CeL.get_URL('http://dict.revised.moe.edu.tw/cgi-bin/cbdic/gsweb.cgi?c