async.js

Ajax下日志框架

    _xhr_canceller: function (req) {
        // IE SUCKS
        try {
            req.onreadystatechange = null;
        } catch (e) {
            try {
                req.onreadystatechange = MochiKit.Async._nothing;
            } catch (e) {
            }
        }
        req.abort();
    },

    
    sendXMLHttpRequest: function (req, /* optional */ sendContent) {
        if (typeof(sendContent) == "undefined" || sendContent === null) {
            sendContent = "";
        }

        var m = MochiKit.Base;
        var self = MochiKit.Async;
        var d = new self.Deferred(m.partial(self._xhr_canceller, req));
        
        try {
            req.onreadystatechange = m.bind(self._xhr_onreadystatechange,
                req, d);
            req.send(sendContent);
        } catch (e) {
            try {
                req.onreadystatechange = null;
            } catch (ignore) {
                // pass
            }
            d.errback(e);
        }

        return d;

    },

    doSimpleXMLHttpRequest: function (url/*, ...*/) {
        var self = MochiKit.Async;
        var req = self.getXMLHttpRequest();
        if (arguments.length > 1) {
            var m = MochiKit.Base;
            var qs = m.queryString.apply(null, m.extend(null, arguments, 1));
            if (qs) {
                url += "?" + qs;
            }
        }
        req.open("GET", url, true);
        return self.sendXMLHttpRequest(req);
    },

    loadJSONDoc: function (url) {
        var self = MochiKit.Async;
        var d = self.doSimpleXMLHttpRequest.apply(self, arguments);
        d = d.addCallback(self.evalJSONRequest);
        return d;
    },

    wait: function (seconds, /* optional */value) {
        var d = new MochiKit.Async.Deferred();
        var m = MochiKit.Base;
        if (typeof(value) != 'undefined') {
            d.addCallback(function () { return value; });
        }
        var timeout = setTimeout(
            m.bind("callback", d),
            Math.floor(seconds * 1000));
        d.canceller = function () {
            try {
                clearTimeout(timeout);
            } catch (e) {
                // pass
            }
        };
        return d;
    },

    callLater: function (seconds, func) {
        var m = MochiKit.Base;
        var pfunc = m.partial.apply(m, m.extend(null, arguments, 1));
        return MochiKit.Async.wait(seconds).addCallback(
            function (res) { return pfunc(); }
        );
    }
});


MochiKit.Async.DeferredLock = function () {
    this.waiting = [];
    this.locked = false;
    this.id = this._nextId();
};

MochiKit.Async.DeferredLock.prototype = {
    __class__: MochiKit.Async.DeferredLock,
    acquire: function () {
        d = new MochiKit.Async.Deferred();
        if (this.locked) {
            this.waiting.push(d);
        } else {
            this.locked = true;
            d.callback(this);
        }
        return d;
    },
    release: function () {
        if (!this.locked) {
            throw TypeError("Tried to release an unlocked DeferredLock");
        }
        this.locked = false;
        if (this.waiting.length > 0) {
            this.locked = true;
            this.waiting.shift().callback(this);
        }
    },
    _nextId: MochiKit.Base.counter(),
    repr: function () {
        var state;
        if (this.locked) {
            state = 'locked, ' + this.waiting.length + ' waiting';
        } else {
            state = 'unlocked';
        }
        return 'DeferredLock(' + this.id + ', ' + state + ')';
    },
    toString: MochiKit.Base.forwardCall("repr")

};

MochiKit.Async.DeferredList = function (list, /* optional */fireOnOneCallback, fireOnOneErrback, consumeErrors, canceller) {
    this.list = list;
    this.resultList = new Array(this.list.length);

    // Deferred init
    this.chain = [];
    this.id = this._nextId();
    this.fired = -1;
    this.paused = 0;
    this.results = [null, null];
    this.canceller = canceller;
    this.silentlyCancelled = false;
    
    if (this.list.length === 0 && !fireOnOneCallback) {
        this.callback(this.resultList);
    }
    
    this.finishedCount = 0;
    this.fireOnOneCallback = fireOnOneCallback;
    this.fireOnOneErrback = fireOnOneErrback;
    this.consumeErrors = consumeErrors;

    var index = 0;
    MochiKit.Base.map(MochiKit.Base.bind(function (d) {
        d.addCallback(MochiKit.Base.bind(this._cbDeferred, this), index, true);
        d.addErrback(MochiKit.Base.bind(this._cbDeferred, this), index, false);
        index += 1;
    }, this), this.list);
};

MochiKit.Base.update(MochiKit.Async.DeferredList.prototype,
                     MochiKit.Async.Deferred.prototype);

MochiKit.Base.update(MochiKit.Async.DeferredList.prototype, {
    _cbDeferred: function (index, succeeded, result) {
        this.resultList[index] = [succeeded, result];
        this.finishedCount += 1;
        if (this.fired !== 0) {
            if (succeeded && this.fireOnOneCallback) {
                this.callback([index, result]);
            } else if (!succeeded && this.fireOnOneErrback) {
                this.errback(result);
            } else if (this.finishedCount == this.list.length) {
                this.callback(this.resultList);
            }
        }
        if (!succeeded && this.consumeErrors) {
            result = null;
        }
        return result;
    }
});

MochiKit.Async.gatherResults = function (deferredList) {
    var d = new MochiKit.Async.DeferredList(deferredList, false, true, false);
    d.addCallback(function (results) {
        var ret = [];
        for (var i = 0; i < results.length; i++) {
            ret.push(results[i][1]);
        }
        return ret;
    });
    return d;
};

MochiKit.Async.maybeDeferred = function (func) {
    var self = MochiKit.Async;
    var result;
    try {
        var r = func.apply(null, MochiKit.Base.extend([], arguments, 1));
        if (r instanceof self.Deferred) {
            result = r;
        } else if (r instanceof Error) {
            result = self.fail(r);
        } else {
            result = self.succeed(r);
        }
    } catch (e) {
        result = self.fail(e);
    }
    return result;
};


MochiKit.Async.EXPORT = [
    "AlreadyCalledError",
    "CancelledError",
    "BrowserComplianceError",
    "GenericError",
    "XMLHttpRequestError",
    "Deferred",
    "succeed",
    "fail",
    "getXMLHttpRequest",
    "doSimpleXMLHttpRequest",
    "loadJSONDoc",
    "wait",
    "callLater",
    "sendXMLHttpRequest",
    "DeferredLock",
    "DeferredList",
    "gatherResults",
    "maybeDeferred"
];
    
MochiKit.Async.EXPORT_OK = [
    "evalJSONRequest"
];

MochiKit.Async.__new__ = function () {
    var m = MochiKit.Base;
    var ne = m.partial(m._newNamedError, this);
    ne("AlreadyCalledError", 
        function (deferred) {
            /***

            Raised by the Deferred if callback or errback happens
            after it was already fired.

            ***/
            this.deferred = deferred;
        }
    );

    ne("CancelledError",
        function (deferred) {
            /***

            Raised by the Deferred cancellation mechanism.

            ***/
            this.deferred = deferred;
        }
    );

    ne("BrowserComplianceError",
        function (msg) {
            /***

            Raised when the JavaScript runtime is not capable of performing
            the given function.  Technically, this should really never be
            raised because a non-conforming JavaScript runtime probably
            isn't going to support exceptions in the first place.

            ***/
            this.message = msg;
        }
    );

    ne("GenericError", 
        function (msg) {
            this.message = msg;
        }
    );

    ne("XMLHttpRequestError",
        function (req, msg) {
            /***

            Raised when an XMLHttpRequest does not complete for any reason.

            ***/
            this.req = req;
            this.message = msg;
            try {
                // Strange but true that this can raise in some cases.
                this.number = req.status;
            } catch (e) {
                // pass
            }
        }
    );


    this.EXPORT_TAGS = {
        ":common": this.EXPORT,
        ":all": m.concat(this.EXPORT, this.EXPORT_OK)
    };

    m.nameFunctions(this);

};

MochiKit.Async.__new__();

MochiKit.Base._exportSymbols(this, MochiKit.Async);