Browser Caching Problem

[stephenalistoun]

Hi all,

This code works fine in firefox but not in internet explorer.


Thanks Stephen

The Code is stated below:

<script type="text/javascript">
	
	function checkEnter(e)
	{
		var keynum;
		var keychar;
		var numcheck;
		
		if(window.event) // IE
		{
		  keynum = e.keyCode;
		}
		else if(e.which) // Netscape/Firefox/Opera
		{
		  keynum = e.which;
		}
		
		if(keynum == 13)
		{
			insertData();
		}

	}
	
	function ajaxRequest()
	{
		var activexmodes=["Msxml2.XMLHTTP", "Microsoft.XMLHTTP"] 
		 //activeX versions to check for in IE
	 
		 if (window.ActiveXObject)
		 { 
			//Test for support for ActiveXObject in IE first (as XMLHttpRequest in IE7 is broken)
			for (var i=0; i<activexmodes.length; i++)
			{
				try
				{
					return new ActiveXObject(activexmodes[i])
				} 
				catch(e)
				{
					alert("Failed");
				}
			}
		 } 
		 else if (window.XMLHttpRequest) 
		 {
			return new XMLHttpRequest()
		 } 
		 else 
		 {
			return false
		 }
		 return;
	}


	function loadURL(url) 
	{
		//to prevent browser from caching data
		var bustcacheparameter=(url.indexOf("?")!=-1)? "&"+new Date().getTime() : "?"+new Date().getTime();
		
		mygetrequest=new this.ajaxRequest()
		mygetrequest.onreadystatechange=function()
		{
			if (mygetrequest.readyState==4)
			{
				if (mygetrequest.status == 200)
				{
					processData(mygetrequest.responseText);  //download successful
					
					
				}
				else
				{
					alert('download failed.');
				}
			}
		}
		
		mygetrequest.open("GET", url+bustcacheparameter, true);
		mygetrequest.send(null);		
	}
	
	function processData(responseText) 
	{
		var countValue = responseText;
		
		if(countValue > 0)
		{
			showChatData("getcd.php");
		}
	}
	
	function init() 
	{
		loadURL("checkUpdate.php");
		
		//Refresh the Screen every 1 second 
		setTimeout("init()",1000);
	}
	
	
	function showChatData(url)
	{
		var bustcacheparameter=(url.indexOf("?")!=-1)? "&"+new Date().getTime() : "?"+new Date().getTime();
	
		mygetrequest=new this.ajaxRequest()
		mygetrequest.onreadystatechange=function()
		{
			if (mygetrequest.readyState==4)
			{
				if (mygetrequest.status == 200)
				{
					showData(mygetrequest.responseText);  //download successful
				}
				else
				{
					alert('download failed.');
				}
			}
		}
		
		mygetrequest.open("GET", url+bustcacheparameter, true);
		mygetrequest.send(null);
	}
	
	
	
	function showData(responseText) 
	{
		document.getElementById("txtHint").innerHTML=responseText;
		
		var objDiv = document.getElementById("txtHint");
			
		objDiv.scrollTop = objDiv.scrollHeight;
	}
	
	
	function insertData()
	{
		str = document.getElementById("chatText").value;
		
		font = document.getElementById("font").value;
		
		var url = "insertRow.php?value=" + str +"&font=" + font;
		
		var bustcacheparameter=(url.indexOf("?")!=-1)? "&"+new Date().getTime() : "?"+new Date().getTime();
	
		mygetrequest=new this.ajaxRequest()
		
		mygetrequest.onreadystatechange=function()
		{
			if (mygetrequest.readyState==4)
			{
				if (mygetrequest.status == 200)
				{
					init();
					
					alert(mygetrequest.status);
				}
				else
				{
					alert("status is " + mygetrequest.status);
				}
			}
		}
		mygetrequest.open("GET", url, true);
		mygetrequest.send(null);
		
		document.getElementById("chatText").value = "";	
	}
	
	
	function smiley(str)
	{
		var temp =  document.getElementById("chatText").value;

		document.getElementById("chatText").value = temp + str;
		
		delayhidemenu();
	}
</script>

[jscheuer1]

There could also be other problems, but unless this function:

	
	function checkEnter(e)
	{
		var keynum;
		var keychar;
		var numcheck;
		
		if(window.event) // IE
		{
		  keynum = e.keyCode;
		}
		else if(e.which) // Netscape/Firefox/Opera
		{
		  keynum = e.which;
		}
		
		if(keynum == 13)
		{
			insertData();
		}

	}

is called something like so in the markup:

<textarea onkeydown="checkEnter(event);">

IE will never get the event, so won't know which key was pressed. This would be a better way:

	function checkEnter(e)
	{
		var keynum;

		e = e || window.event;
		keynum = e.keyCode || e.which;

		if(keynum == 13)
		{
			insertData();
		}

	}

It will work even if the call is like:

document.onkeydown = checkEnter;

or attached/added using addEventListener/attachEvent.

It's hard to pick out anything really off about the rest of the code. I'll have another look, but it would help to have a link to the page.

[jscheuer1]

I just saw something else, just as a matter of logic, in this function:

	function insertData()
	{
		str = document.getElementById("chatText").value;
		
		font = document.getElementById("font").value;
		
		var url = "insertRow.php?value=" + str +"&font=" + font;
		
		var bustcacheparameter=(url.indexOf("?")!=-1)? "&"+new Date().getTime() : "?"+new Date().getTime();
	
		mygetrequest=new this.ajaxRequest()
		
		mygetrequest.onreadystatechange=function()
		{
			if (mygetrequest.readyState==4)
			{
				if (mygetrequest.status == 200)
				{
					init();
					
					alert(mygetrequest.status);
				}
				else
				{
					alert("status is " + mygetrequest.status);
				}
			}
		}
		mygetrequest.open("GET", url + bustcacheparameter, true);
		mygetrequest.send(null);
		
		document.getElementById("chatText").value = "";	
	}

You should add the highlighted as shown.