// A generic function for performming AJAX requests // It takes one argument, which is an object that contains a set of options // All of which are outline in the comments, below function ajax( options ) { // Load the options object with defaults, if no // values were provided by the user options = { // The type of HTTP Request type: options.type || "POST", // The URL the request will be made to url: options.url || "", // How long to wait before considering the request to be a timeout timeout: options.timeout || 5000, // Functions to call when the request fails, succeeds, // or completes (either fail or succeed) onComplete: options.onComplete || function(){}, onError: options.onError || function(){}, onSuccess: options.onSuccess || function(){}, // The data type that'll be returned from the server // the default is simply to determine what data was returned from the // and act accordingly. data: options.data || "" }; // Create the request object var xml = (document.all) ? new ActiveXObject("Microsoft.XMLHTTP") : new XMLHttpRequest(); // Open the asynchronous POST request xml.open(options.type, options.url, true); // We're going to wait for a request for 5 seconds, before giving up var timeoutLength = 5000; // Keep track of when the request has been succesfully completed var requestDone = false; // Initalize a callback which will fire 5 seconds from now, cancelling // the request (if it has not already occurred). setTimeout(function(){ requestDone = true; }, timeoutLength); // Watch for when the state of the document gets updated xml.onreadystatechange = function(){ // Wait until the data is fully loaded, // and make sure that the request hasn't already timed out if ( xml.readyState == 4 && !requestDone ) { // Check to see if the request was successful if ( httpSuccess( xml ) ) { // Execute the success callback with the data returned from the server options.onSuccess( httpData( xml, options.type ) ); // Otherwise, an error occurred, so execute the error callback } else { options.onError(); } // Call the completion callback options.onComplete(); // Clean up after ourselves, to avoid memory leaks xml = null; } }; // Establish the connection to the server xml.send(); // Determine the success of the HTTP response function httpSuccess(r) { try { // If no server status is provided, and we're actually // requesting a local file, then it was successful return !r.status && location.protocol == "file:" || // Any status in the 200 range is good ( r.status >= 200 && r.status < 300 ) || // Successful if the document has not been modified r.status == 304 || // Safari returns an empty status if the file has not been modified navigator.userAgent.indexOf("Safari") >= 0 && typeof r.status == "undefined"; } catch(e){} // If checking the status failed, then assume that the request failed too return false; } // Extract the correct data from the HTTP response function httpData(r,type) { // Get the content-type header var ct = r.getResponseHeader("content-type"); // If no default type was provided, determine if some // form of XML was returned from the server var data = !type && ct && ct.indexOf("xml") >= 0; // Get the XML Document object if XML was returned from // the server, otherwise return the text contents returned by the server data = type == "xml" || data ? r.responseXML : r.responseText; // If the specified type is "script", execute the returned text // response as if it was JavaScript if ( type == "script" ) eval.call( window, data ); // Return the response data (either an XML Document or a text string) return data; } } // communication utils if (!argos) var argos = {}; argos.comms = { /** * * URL encode / decode * http://www.webtoolkit.info/ * **/ url : { URI_SEP : "?", PARAM_DELIM : "&", PARAM_ASSIGN_CHAR : "=", ANCHOR_CHAR : "#", // public method for url encoding encode : function (string) { return escape(this._utf8_encode(string)); }, // public method for url decoding decode : function (string) { return this._utf8_decode(unescape(string)); }, // private method for UTF-8 encoding _utf8_encode : function (string) { string = string.replace(/\r\n/g,"\n"); var utftext = ""; for (var n = 0; n < string.length; n++) { var c = string.charCodeAt(n); if (c < 128) { utftext += String.fromCharCode(c); } else if((c > 127) && (c < 2048)) { utftext += String.fromCharCode((c >> 6) | 192); utftext += String.fromCharCode((c & 63) | 128); } else { utftext += String.fromCharCode((c >> 12) | 224); utftext += String.fromCharCode(((c >> 6) & 63) | 128); utftext += String.fromCharCode((c & 63) | 128); } } return utftext; }, // private method for UTF-8 decoding _utf8_decode : function (utftext) { var string = ""; var i = 0; var c = c1 = c2 = 0; while ( i < utftext.length ) { c = utftext.charCodeAt(i); if (c < 128) { string += String.fromCharCode(c); i++; } else if((c > 191) && (c < 224)) { c2 = utftext.charCodeAt(i+1); string += String.fromCharCode(((c & 31) << 6) | (c2 & 63)); i += 2; } else { c2 = utftext.charCodeAt(i+1); c3 = utftext.charCodeAt(i+2); string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63)); i += 3; } } return string; }, /** * Parse an URL string and get the value for a given parameter * @url the URL to be parsed * @name the parameter name */ getParameter : function(url, name) { var value = null; // parameter value // validate input url and name and if url has parameters before parsing if (url && name && url.indexOf(argos.comms.url.URI_SEP)!=-1) { var paramStr = url.substring(url.indexOf(argos.comms.url.URI_SEP)); var paramIndex = paramStr.indexOf(name); if (paramIndex!=-1) { // parameter found var valueStart = paramIndex + name.length + argos.comms.url.PARAM_ASSIGN_CHAR.length; var valueEnd = paramStr.indexOf(argos.comms.url.PARAM_DELIM, valueStart); if (valueEnd == -1) { // parameter is the last one valueEnd = paramStr.indexOf(argos.comms.url.ANCHOR_CHAR, valueStart); if (valueEnd == -1) { // check for anchor maker valueEnd = paramStr.length; } } value = paramStr.substring(valueStart, valueEnd); } } return value; } } };