tube/tube.js

Experimental Resource Loader implementing using Server Sent Events

var tube = (function() {
    function Manifest() {
        this.resources = [];
    }
    
    Manifest.prototype = {
        add: function(data) {
            // add the resource
            this.resources.push(data);
        }
    };
    
    Object.defineProperty(Manifest.prototype, 'files', {
        get: function() {
            return this.resources.map(function(resource) {
                return resource.path;
            });
        }
    });
    
    if (typeof module != 'undefined' && module.exports) {
        module.exports = Manifest;
    }
    
    function Tube(endpoint, opts) {
        // ensure we have opts
        opts = opts || {};
    
        // initialise the number of connections
        this.multi = opts.multi || 2;
    
        // initialise the separator
        this.separator = opts.separator || String.fromCharCode(0x214B);

        // initialise the event sources
        this.sources = this.connect(endpoint);
    }
    
    Tube.prototype = {
        /**
        ## connect(endpoint: String)
        */
        connect: function(endpoint) {
            var connections = [],
                separator = this.separator;
            
            // initialise the connections
            for (var ii = 0; ii < this.multi; ii++) {
                connections[ii] = new EventSource(endpoint + '?p=' + ii);
            }
            
            console.log(separator);
            
            // handle connection behaviour
            connections.forEach(function(connection) {
                connection.addEventListener('exception', function(evt) {
                    console.log('received exception', evt.data);
                }, false);
                
                connection.addEventListener('resource', function(evt) {
                    var resource, script, text;
                    
                    // parse the data
                    try {
                        resource = JSON.parse(evt.data);
                        
                        // create a script tag
                        script = document.createElement('script');
                        
                        // create a text node for the script content
                        script.appendChild(
                            document.createTextNode(resource.data.split(separator).join('\n'))
                        );
                        
                        // add the script to the document
                        document.body.appendChild(script);
                    }
                    catch (e) {
                        
                    }
                });
                
                connection.addEventListener('done', function(evt) {
                    console.log('received done', evt);
                    connection.close();
                }, false);
            });
    
            return connections;
        }
    };
    
    // mixin asevented
    // asEvented.call(Tube.prototype);
    
    return function(endpoint, opts) {
        return new Tube(endpoint, opts);
    };
}());