用javascript读取xml值
我正试图做一个小项目的基础上 无论如何，我需要从xml文件中读取一个值，并通过javascript将其打印到网页中。问题是，当我将值放入变量时，它似乎不是一个有效的数字。这是我的密码： index.html用javascript读取xml值,javascript,jquery,xml,jqplot,Javascript,Jquery,Xml,Jqplot,我正试图做一个小项目的基础上 无论如何，我需要从xml文件中读取一个值，并通过javascript将其打印到网页中。问题是，当我将值放入变量时，它似乎不是一个有效的数字。这是我的密码： index.html <html> <head> <meta http-equiv="Content-Type" content="text/html;charset=UTF-8" /> <script language="javascript" type="te
<html>
<head>
<meta http-equiv="Content-Type" content="text/html;charset=UTF-8" />
<script language="javascript" type="text/javascript" src="jquery.min.js"></script>
<script language="javascript" type="text/javascript" src="jquery.jqplot.min.js"></script>
<script type="text/javascript" src="mchp.js"></script>
<link rel="stylesheet" type="text/css" href="jquery.jqplot.css" />
</head>
<body>
<div id="chartdiv" style="height:400px;width:600px;" align="center"></div>
<script type="text/javascript">
var x=getXMLValue('status.xml','key');
var y=parseFloat(x);
$.jqplot('chartdiv', [[[-24, y],[-20,5.12],[-17,13.1],[-15,33.6],[-7,85.9],[-2,219.9]]],
{
axes:{
xaxis:{min:-24, max:-1},
yaxis:{min:-24, max:50+2}
},
grid: {
background: 'rgba(00,00,00,0.0)',
drawBorder: false,
shadow: false,
gridLineColor: '#FFFFFF',
gridLineWidth: 2},
title: 'Temperature',
animate : true,
showTicks: true,
series: [{color: '#FF0000'}],
}
);
</script>
</body>
</html>
我认为jquery和jqplot文件在这种情况下并不重要，但如果需要，我可以提供链接。我认为问题在于读取或转换xml数据。提前感谢您的帮助 您正在解析的不是xml，而是字符串“status.xml”。问题在于您以错误的方式调用getXMLValue。getXMLValue需要一个已解析的xml文档，而不是带有url/文件名的字符串。您需要调用返回status.xml的url。例如，由于您使用的是jQuery，因此可以执行以下操作：
jQuery.ajax({
type : "GET",
url : "http://localhost/status.xml",
dataType : "xml",
success : function(xml) {
var y = parseFloat(getXMLValue(xml,key));
jQuery.jqplot('chartdiv', [[[-24, y],[-20,5.12],[-17,13.1],[-15,33.6],[-7,85.9],[-2,219.9]]],{
axes:{
xaxis:{min:-24, max:-1},
yaxis:{min:-24, max:50+2}
},
grid: {
background: 'rgba(00,00,00,0.0)',
drawBorder: false,
shadow: false,
gridLineColor: '#FFFFFF',
gridLineWidth: 2},
title: 'Temperature',
animate : true,
showTicks: true,
series: [{color: '#FF0000'}],
});
},
error : function(xhr) {
alert(xhr.responseText);
}
});
// Determines when a request is considered "timed out"
var timeOutMS = 5000; //ms
// Stores a queue of AJAX events to process
var ajaxList = new Array();
// Initiates a new AJAX command
// url: the url to access
// container: the document ID to fill, or a function to call with response XML (optional)
// repeat: true to repeat this call indefinitely (optional)
// data: an URL encoded string to be submitted as POST data (optional)
function newAJAXCommand(url, container, repeat, data)
{
// Set up our object
var newAjax = new Object();
var theTimer = new Date();
newAjax.url = url;
newAjax.container = container;
newAjax.repeat = repeat;
newAjax.ajaxReq = null;
// Create and send the request
if(window.XMLHttpRequest) {
newAjax.ajaxReq = new XMLHttpRequest();
newAjax.ajaxReq.open((data==null)?"GET":"POST", newAjax.url, true);
newAjax.ajaxReq.send(data);
// If we're using IE6 style (maybe 5.5 compatible too)
} else if(window.ActiveXObject) {
newAjax.ajaxReq = new ActiveXObject("Microsoft.XMLHTTP");
if(newAjax.ajaxReq) {
newAjax.ajaxReq.open((data==null)?"GET":"POST", newAjax.url, true);
newAjax.ajaxReq.send(data);
}
}
newAjax.lastCalled = theTimer.getTime();
// Store in our array
ajaxList.push(newAjax);
}
// Loops over all pending AJAX events to determine if any action is required
function pollAJAX() {
var curAjax = new Object();
var theTimer = new Date();
var elapsed;
// Read off the ajaxList objects one by one
for(i = ajaxList.length; i > 0; i--)
{
curAjax = ajaxList.shift();
if(!curAjax)
continue;
elapsed = theTimer.getTime() - curAjax.lastCalled;
// If we suceeded
if(curAjax.ajaxReq.readyState == 4 && curAjax.ajaxReq.status == 200) {
// If it has a container, write the result
if(typeof(curAjax.container) == 'function'){
curAjax.container(curAjax.ajaxReq.responseXML.documentElement);
} else if(typeof(curAjax.container) == 'string') {
document.getElementById(curAjax.container).innerHTML = curAjax.ajaxReq.responseText;
} // (otherwise do nothing for null values)
curAjax.ajaxReq.abort();
curAjax.ajaxReq = null;
// If it's a repeatable request, then do so
if(curAjax.repeat)
newAJAXCommand(curAjax.url, curAjax.container, curAjax.repeat);
continue;
}
// If we've waited over 1 second, then we timed out
if(elapsed > timeOutMS) {
// Invoke the user function with null input
if(typeof(curAjax.container) == 'function'){
curAjax.container(null);
} else {
// Alert the user
alert("Command failed.\nConnection to development board was lost.");
}
curAjax.ajaxReq.abort();
curAjax.ajaxReq = null;
// If it's a repeatable request, then do so
if(curAjax.repeat)
newAJAXCommand(curAjax.url, curAjax.container, curAjax.repeat);
continue;
}
// Otherwise, just keep waiting
ajaxList.push(curAjax);
}
// Call ourselves again in 100ms
setTimeout("pollAJAX()",100);
}
// Parses the xmlResponse returned by an XMLHTTPRequest object
// xmlData: the xmlData returned
// field: the field to search for
function getXMLValue(xmlData, field) {
try {
if(xmlData.getElementsByTagName(field)[0].firstChild.nodeValue)
return xmlData.getElementsByTagName(field)[0].firstChild.nodeValue;
else
return null;
} catch(err) { return null; }
}
//kick off the AJAX Updater
setTimeout("pollAJAX()",500);
jQuery.ajax({
type : "GET",
url : "http://localhost/status.xml",
dataType : "xml",
success : function(xml) {
var y = parseFloat(getXMLValue(xml,key));
jQuery.jqplot('chartdiv', [[[-24, y],[-20,5.12],[-17,13.1],[-15,33.6],[-7,85.9],[-2,219.9]]],{
axes:{
xaxis:{min:-24, max:-1},
yaxis:{min:-24, max:50+2}
},
grid: {
background: 'rgba(00,00,00,0.0)',
drawBorder: false,
shadow: false,
gridLineColor: '#FFFFFF',
gridLineWidth: 2},
title: 'Temperature',
animate : true,
showTicks: true,
series: [{color: '#FF0000'}],
});
},
error : function(xhr) {
alert(xhr.responseText);
}
});