「リクエストを受けた順番に通信&処理を行うXMLHTTPクライアント」のプロトタイプ

gistfile1.js

this.QUERY = new Query;
// var client = {};
//
// /* client.A と client.B は非同期 */
// client.A = client.A || new XMLHttpClient;
// client.B = client.B || new XMLHttpClient;
//
// /*
//    pushしたリクエストは、pushした順番に処理。
//    １つのリクエストを処理を完了するまで、次のリクエストは待っている
// */
//
// client.A
//    .push('GET', '/path?foo=hoge', function (response) { ... })
//    .push('GET', '/path?user=unknown&pass=0123',  function (response) { ... })
// ;
//
// client.B
//    .push('GET', '/path_another?foo=hoge', function (response) { ... })
//    .push('GET', '/path_another?user=yourself&pass=both',  function (response) { ... })
// ;
//
// /* listenメソッドで通信(&処理)を開始する */
// client.A.listen();
// client.B.listen();
function XMLHttpClient () {
    this.queue  = [];
    this.state  = false;
    this.client = new XMLHttpRequest();
}
(function () {
    function _reFormatHttpRequest1 (method) {
        if (method === 'POST') {
            if (this[0].match(/\?/)) {
                var buf  = this[0].split(/\?/);
                this[0] = buf[0];
                this[1] = buf[1];
            }
        }
    }
    function _reFormatHttpRequest2 (method) {
        // this[1] == null 以外は、stringに直し、method === 'POST' -> body, method === 'GET' -> urlに追加
        var buf = QUERY.stringify(this[1]);
        if (method === 'POST') {
            this[1] = buf;
        } else {
            this[1] = null;
            this[0] = (buf) ? [ this[0], buf ].join((buf.match(/^\?/)) ? '' : '?') : this[0];
        }
    }
    function reFormatHttpRequest (method, httpRequest) {
        if (! method) return { error : '"method" not found' };
        if (! httpRequest)    return { error : '"httpRequest object" not found' };

        method = (method.match(/^post/i)) ? 'POST' : 'GET';

        var url, body = null, headers = {}, httpRequestObj = [ url, body, headers ];
        
        if (typeof httpRequest === 'string') {
            httpRequestObj[0] = httpRequest;
            _reFormatHttpRequest1.apply(httpRequestObj, [ method ]);
            return httpRequestObj;
        }

        if (! httpRequest.length) return { error : 'httpRequest must be "string" or "array"' };
        if (typeof httpRequest[0] !== 'string') return { error : '"url" must be "string"' };

        httpRequestObj[0] = httpRequest[0];
        _reFormatHttpRequest1.apply(httpRequestObj, [ method ]);

        httpRequestObj[1] = httpRequest[1] || httpRequestObj[1];
        _reFormatHttpRequest2.apply(httpRequestObj, [ method ]);

        httpRequestObj[2] = httpRequest[2] || {};

        return httpRequestObj;
    }

    XMLHttpClient.prototype.push = function (method, httpRequest, callback, async) {
        method = (method.match(/^post$/i)) ? 'POST' : 'GET';
        httpRequest = reFormatHttpRequest(method, httpRequest);
        if (method === 'POST') httpRequest[2]['Content-Type'] = 'application/x-www-form-urlencoded';

        this.queue.push({
            method   : method,
            url      : httpRequest[0], // url,
            body     : httpRequest[1], // body,
            headers  : httpRequest[2], // headers,
            callback : callback,
            async    : (async === false) ? false : true // 明示的に false しないと、true で非同期処理
        });

        return this;
    };

    XMLHttpClient.prototype.listen = function () {
        if (this.queue && this.queue.length > 0) {
            if (this.state) {
                setTimeout(this.listen, 1);
            } else {
                run.apply(this); //this.run();
            }
        }
        return this;
    };

    //XMLHttpClient.prototype.run = function () {
    function run () {
        var self   = this,
            client = this.client,
            req
        ;

        if (this.queue.length > 0) {
            this.state = true;
            req = this.queue.shift();

            client.onreadystatechange = function () {
                if (client.readyState === 4) {
                    if (client.status >= 200 && client.status < 300) {
                        var responseHeaders = {};
                        client.getAllResponseHeaders().split(/\r\n/).foreach(function (header) {
                            var keyVal = header.split(/:\s?/);
                            responseHeaders[keyVal[0]] = keyVal[1];
                        });
                        req.callback([ client.status, responseHeaders, client.responseText ]);
                    } else {
                        throw new Error([ client.status, client.statusText ].join(': '));
                    }
                    self.state = false;
                    if (self.queue && self.queue.length > 0) self.listen(); // あやしい
                } else {
                    ;
                }
            };

            client.open(req.method, req.url, req.async);
            if (req.headers) {
                for (var key in req.headers) {
                    client.setRequestHeader(key, req.headers[key]);
                }
            }
            client.send(req.body);

        }
        return this;
    }//;

}) ();


// query
function Query () {};
(function (Q) {
    Q.parse = function (str, type) {
        type = type || 'HASH';
        type = (type.match(/^array$/i)) ? 'ARRAY' : 'HASH';

        if (! str) return (type === 'ARRAY') ? [] : {};

        if (typeof str !== 'string') return { error: 'failed: 1st argument must be "string"' };

        str = (str.match(/^\?/)) ? str.slice(1) : str;

        var obj, buf;

        if (type === 'ARRAY') {
            obj = [];
            (str.split(/&/)).foreach(function (keyVal) {
                buf = keyVal.split(/=/);
                obj.push([ buf[0], decodeURIComponent(buf[1]) ]);
            });
            return obj;
        }

        if (type === 'HASH') {
            obj = {};
            (str.split(/&/)).foreach(function (keyVal) {
                buf = keyVal.split(/=/);
                obj[ buf[0] ] = decodeURIComponent(buf[1]);
            });
            return obj;
        }
    };

    Q.stringify = function (obj) {
        if (! obj) return null; // '';

        if (typeof obj === 'string') return obj;

        var buf = [];

        if (obj instanceof Array) {
            obj.foreach(function (keyVal) {
                buf.push([ keyVal[0], encodeURIComponent(keyVal[1]) ].join('='));
            });
            return (buf.length > 0) ? buf.join('&') : null;
        }

        if (typeof obj === 'object') {
            for (var key in obj) {
                buf.push([ key, encodeURIComponent(obj[key]) ].join('='));
            }
            return (buf.length > 0) ? buf.join('&') : null;
        }

        return { error: 'failed: arguments must be "hash" or "array"' };
    };
}) (Query.prototype);

• readyState < 4 の時の処理
• status != 2xx の時の処理
• uri, requestheader の処理

function foreach (arry, func) {
var i =0, len = arry.length;
if (len) {
for (; i < len; i += 1) {
func(arry[i], i);
}
}
}
if (! Array.prototype.foreach) {
Array.prototype.foreach = function (func) {
foreach.apply(null, [ this, func ]);
};
}