brat-frontend-editor/client/src/wa_dispatcher.js

"BRAT Editor standalone frontend library"

/*
 * ## brat ##
 * Copyright (C) 2010-2012 The brat contributors, all rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is furnished to do
 * so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
// -*- Mode: JavaScript; tab-width: 2; indent-tabs-mode: nil; -*-
// vim:set ft=javascript ts=2 sw=2 sts=2 cindent:
// TODO: does 'arguments.callee.caller' work?

var Dispatcher = (function($, window, undefined) {
    var Dispatcher = function() {
        var that = this;

        var table = {};

// WEBANNO EXTENSION BEGIN
        var ajaxUrl = 'ajax.cgi';
// WEBANNO EXTENSION END

        var on = function(message, host, handler) {
            if (handler === undefined) {
                handler = host;
                host = arguments.callee.caller;
            }
            if (table[message] === undefined) {
                table[message] = [];
            }
            table[message].push([host, handler]);
            return this;
        };

        // Notify listeners that we encountered an error in an asynch call
        var inAsynchError = false; // To avoid error avalanches
        var handleAsynchError = function(e) {
            if (!inAsynchError) {
                inAsynchError = true;
                // TODO: Hook printout into dispatch elsewhere?
                console.warn('Handled async error:', e);
                that.post('dispatchAsynchError', [e]);
                inAsynchError = false;
            } else {
                console.warn('Dropped asynch error:', e);
            }
        };
// WEBANNO EXTENSION BEGIN
        that.on = on;
        that.handleAsynchError = handleAsynchError;
        that.post = post;
        that.proxy = proxy;
// WEBANNO EXTENSION END

        var post = function(asynch, message, args, returnType) {
            if (typeof(asynch) !== 'number') {
                // no asynch parameter
                returnType = args;
                args = message;
                message = asynch;
                asynch = null;
            }
            if (args === undefined) {
                args = [];
            }
            var results = [];
            // DEBUG: if (typeof(message) != "string" || !(message.match(/mouse/) || message == "hideComment")) console.log(message, args);

            if (typeof(message) === 'function') {
                // someone was lazy and sent a simple function
                var host = arguments.callee.caller;
                if (asynch !== null) {
                    result = setTimeout(function() {
                        try {
                            message.apply(host, args);
                        } catch(e) {
                            that.handleAsynchError(e);
                        }
                    }, asynch);
                } else {
                    result = message.apply(host, args);
                }
                results.push(result);
            } else {
                // a proper message, propagate to all interested parties
                var todo = table[message];
                if (todo !== undefined) {
                    $.each(todo, function(itemNo, item) {
                        var result;
                        if (asynch !== null) {
                            result = setTimeout(function() {
                                try {
                                    item[1].apply(item[0], args);
                                } catch (e) {
                                    that.handleAsynchError(e);
                                }
                            }, asynch);
                        } else {
                            result = item[1].apply(item[0], args);
                        }
                        results.push(result);
                    });
                    /* DEBUG
                     } else {
                     console.warn('Message ' + message + ' has no subscribers.'); // DEBUG
                     */
                }
            }
            if (returnType == 'any') {
                var i = results.length;
                while (i--) {
                    if (results[i] !== false) return results[i];
                }
                return false;
            }
            if (returnType == 'all') {
                var i = results.length;
                while (i--) {
                    if (results[i] === false) return results[i];
                }
            }
            return results;
        };

        var proxy = function(destination, message) {
            this.on(message, function() {
                destination.post(message, Array.prototype.slice.call(arguments));
            });
        };

        var dispatcher = {
            on: on,
            post: post,
            proxy: proxy,
        };
        Dispatcher.dispatchers.push(dispatcher);
        return dispatcher;
    };

    Dispatcher.dispatchers = [];
    Dispatcher.post = function(asynch, message, args, returnType) {
        $.each(Dispatcher.dispatchers, function(dispatcherNo, dispatcher) {
            dispatcher.post(asynch, message, args, returnType);
        });
    };

    return Dispatcher;
})(jQuery, window);