ajax.js

一个开源的rfid middleware 资料

/*
     General AJAX technique samples--how to talk to the server + return data and do stuff with it.
     Direct questions, answers, rants, flames, kudos to [e-mail]
     Steve Benfield

      1.0: 2005-07-14   Initial Release
      1.1: 2005-07-15   Fixed bugs, changed text for clarity, added ability to register for updates
     
*/
     
var _ms_XMLHttpRequest_ActiveX = ""; // Holds type of ActiveX to instantiate
var _ajax;                           // Reference to a global XMLHTTPRequest object for some of the samples
var _logger = true;                  // write output to the Activity Log
var _status_area;                    // will point to the area to write status messages to

if (!window.Node || !window.Node.ELEMENT_NODE) {
    var Node = { ELEMENT_NODE: 1, ATTRIBUTE_NODE: 2, TEXT_NODE: 3, CDATA_SECTION_NODE: 4, ENTITY_REFERENCE_NODE: 5,
                 ENTITY_NODE: 6, PROCESSING_INSTRUCTION_NODE: 7, COMMENT_NODE: 8, DOCUMENT_NODE: 9, DOCUMENT_TYPE_NODE: 10, DOCUMENT_FRAGMENT_NODE: 11, NOTATION_NODE: 12 };
}

// initialize the global AJAX object
// lots of samples that discuss AJAX use a global variable
// so I started these samples with one
// some examples use the "global" one and others use an encapsulated one that requires a new (a better approach!)
_ajax = startAJAX();

// From prototype.js @ www.conio.net | Returns an object reference to one or more strings
// ignore the fact that there are no arguments to this method -- javascript doesn't care how many you send (not strongly typed)
// The method checks the actual # of arguments -- returns a single object or an array
function $() {
    var elements = new Array();

    for (var i = 0; i < arguments.length; i++) {
        var element = arguments[i];

        if (typeof element == 'string')
            element = document.getElementById(element);

        if (arguments.length == 1)
            return element;

        elements.push(element);
    }

    return elements;
}

function getTextFromXML( oNode, deep ) {
    var s = "";
    var nodes = oNode.childNodes;

    for (var i = 0; i < nodes.length; i++) {
        var node = nodes[i];

        if (node.nodeType == Node.TEXT_NODE) {
            s += node.data;
        } else if (deep == true && (node.nodeType == Node.ELEMENT_NODE || node.nodeType == Node.DOCUMENT_NODE
                                       || node.nodeType == Node.DOCUMENT_FRAGMENT_NODE)) {
            s += getTextFromXML(node, true);
        };
    }

    ;
    return s;
}

;

// If you plan on doing anything outside of the US of A, then you'd better encode the things you pass back and forth
// the escape() method in Javascript is deprecated -- should use encodeURIComponent
function encode( uri ) {
    if (encodeURIComponent) {
        return encodeURIComponent(uri);
    }

    if (escape) {
        return escape(uri);
    }
}

function decode( uri ) {
    uri = uri.replace(/\+/g, ' ');

    if (decodeURIComponent) {
        return decodeURIComponent(uri);
    }

    if (unescape) {
        return unescape(uri);
    }

    return uri;
}

function logger( text, clear ) {
    if (_logger) {
        if (!_status_area) {
            _status_area = document.getElementById("status_area");
        }

        if (_status_area) {
            if (clear) {
                _status_area.value = "";
            }

            var old = _status_area.value;
            _status_area.value = text + ((old) ? "\r\n" : "") + old;
        }
    }
}

function initAJAX( method, url, changeHandler, async ) {
    if (typeof async == "undefined")
        async = true;

    if (changeHandler) {
        _ajax.onreadystatechange = changeHandler;
    }

    if (!method) {
        method = "POST";
    }

    method = method.toUpperCase();
    method = (method.charAt(0) == "G") ? "GET" : "POST";

    logger("----------------------------------------------------------------------");
    logger(((async) ? "Async" : "Sync") + " " + method + ": URL: " + url);

    _ajax.open(method, url, async);

    if (method == "POST") {
        _ajax.setRequestHeader("Connection", "close"); //overcome a bug in recent Firefox builds
        _ajax.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
        _ajax.setRequestHeader("Method", "POST " + url + "HTTP/1.1");
    }
}

function startAJAX() {
    var _myAjax = null;

    if (window.XMLHttpRequest) {
        _myAjax = new XMLHttpRequest();
    } else if (window.ActiveXObject) {
        // Instantiate the latest MS ActiveX Objects
        var versions = ["Msxml2.XMLHTTP.5.0", "Msxml2.XMLHTTP.4.0", "MSXML2.XMLHTTP.3.0", "MSXML2.XMLHTTP",
                        "Microsoft.XMLHTTP"];

        if (_ms_XMLHttpRequest_ActiveX) {
            _myAjax = new ActiveXObject(_ms_XMLHttpRequest_ActiveX);
        } else {
            for (var i = 0; i < versions.length ; i++) {
                try {
                    _myAjax = new ActiveXObject(versions[i]);

                    if (_myAjax) {
                        _ms_XMLHttpRequest_ActiveX = versions[i];
                        break;
                    }
                }
                catch (objException) {
                // trap; try next one
                }

                ;
            }

            ;
        }
    }

    return _myAjax;
}



// handle some key press events
function handleKeyUp( e ) {
    e = (!e) ? window.event : e;
    target = (!e.target) ? e.srcElement : e.target;
    logger('keyup');

    if (e.type == "keyup") {
        // skip shift, alt, control keys
        if (e.keyCode == 16 || e.keyCode == 17 || e.keyCode == 18) {
        // do nothing
        }

        else {
            if (target.name == "state1" && !$('state1').value) {
                clearCustomersByState();
            } else if (target.name == "state2" && !$('state2').value) {
                clearCustomersByStateXML();
            } else if (target.name == "google_search") {
                if (target.value) {
                    getSuggest(target);
                } else {
                    $('google_suggest_target').innerHTML = "";
                }
            }
        }
    }
}

<!------------------------------- BEGIN PING ---------------------------------------------------->


function ping() {
    var url = '/custom/servlet/ReaderListener';
    initAJAX("post", url, function () {
	    if ( _ajax.readyState == 4 ) {
		    logger("Response from the server: " + _ajax.responseText);
		    //$("ping_status").innerHTML =  _ajax.responseText;
            $('content:ping_status').value =  _ajax.responseText;
  		    
	    }
    });
    logger("Sent To The Server: value=" + encode('teste'));
    _ajax.send("value=" + encode('54545'));
   
}


function pingjsf() {
    var url = '/admin/jsp/body/sealMonitor.jsf';
    initAJAX("post", url, function () {
        if ( _ajax.readyState == 4 ) {
            logger("Response from the server: " + _ajax.responseText);
            //$("ping_status").innerHTML =  _ajax.responseText;
           $('content-panel').innerHTML =  _ajax.responseText;
            
        }
    });
    logger("Sent To The Server: value=" + encode('teste'));
    _ajax.send("value=" + encode('54545'));
   pingjsfAgain();
}



function buildReport(req) {
    var select = document.getElementById("ping_status");
    var items = req.responseXML.getElementsByTagName("report");
    // loop through <item> elements, and add each nested
    // <title> element to Topics select element
    for (var i = 0; i < items.length; i++) {
        appendToSelect(select, i,
            document.createTextNode(getElementTextNS("", "epc", items[i], 0)));
    }
    // clear detail display
    //document.getElementById("ping_status").innerHTML = "";
}

// retrieve text of an XML document element, including
// elements using namespaces
function getElementTextNS(prefix, local, parentElem, index) {
    var result = "";
    if (prefix && isIE) {
        // IE/Windows way of handling namespaces
        result = parentElem.getElementsByTagName(prefix + ":" + local)[index];
    } else {
        // the namespace versions of this method 
        // (getElementsByTagNameNS()) operate
        // differently in Safari and Mozilla, but both
        // return value with just local name, provided 
        // there aren't conflicts with non-namespace element
        // names
        result = parentElem.getElementsByTagName(local)[index];
    }
    if (result) {
        // get text, accounting for possible
        // whitespace (carriage return) text nodes 
        if (result.childNodes.length > 1) {
            return result.childNodes[1].nodeValue;
        } else {
            return result.firstChild.nodeValue;    		
        }
    } else {
        return "n/a";
    }
}
function spam( num ) {
    $('spam_time').innerHTML = "Initiating " + num + " XMLHttpRequests.";
    var startTime = new Date();
    startAJAX();

    //_logger = false;
    for (var i = 1; i <= num; i++) {
        initAJAX("post", '/ThinkCAP/servlet/ping', null, false);
        _ajax.send("hide=1&num=" + i);
    }

    var endTime = new Date()
    var millis = endTime - startTime;
    _logger = true;
    logger("time to spam the server with " + num + " requests: " + (millis / 1000).toFixed(2) + " seconds. " + (millis / 1000 / num).toFixed(2) + " seconds per request.");
    $('spam_time').innerHTML = num + " requests took " + (millis / 1000).toFixed(2) + " seconds. " + (millis / 1000 / num).toFixed(2) + " seconds per request.";
}

function getBigFile() {
    // This is a fully encapsulated XMLHTTP Request
    // The return function is included inside this
    // Also we add a pointer back to this function's instance of _myAjax so that it can be aborted
    var self = this;
    // we don't use "this" throughout the function because it won't work in the anonymous function declaration
    self._myAjax = startAJAX();
    self._myCount = 0;
    self._big_file_status = $('big_file_status');
    self._big_file_status.value = 'Retrieving Large File...';
    $('big_file_status_button').style.display = 'inline';
    $('big_file_status_button').ajaxHandle = self._myAjax;