XMLHTTP Help

Canman2005 · April 25, 2010

Hi all

Wonder if someone can help

I have the following code

// declare a global  XMLHTTP Request object

var XmlHttpObj;

function CreateXmlHttpObj()

{
     
    try
    
    {
        
        XmlHttpObj = new ActiveXObject("Msxml2.XMLHTTP");
        
    }
    
    catch(e)
    
    {
        
        try
        
        {
            
            XmlHttpObj = new ActiveXObject("Microsoft.XMLHTTP");
            
        }
        
        catch(oc)
        
        {
            
            XmlHttpObj = null;
            
        }
        
    }
      
    if(!XmlHttpObj && typeof XMLHttpRequest != "undefined")
    
    {
        
        XmlHttpObj = new XMLHttpRequest();
        
    }
    
}

function ListOnChange()

{
    
    var county = document.getElementById("county");
    
   
    var selectedContinent = county.options[county.selectedIndex].value;
    
  
    var requestUrl;
  
    requestUrl = "code/xml.php" + "?filter=" + encodeURIComponent(selectedContinent);
        
    CreateXmlHttpObj();
    
  
    if(XmlHttpObj)
    
    {
              
        XmlHttpObj.onreadystatechange = StateChangeHandler;
    
        XmlHttpObj.open("GET", requestUrl,  true);
                
        XmlHttpObj.send(null);
        
    }
}

function StateChangeHandler()

{
       
    if(XmlHttpObj.readyState == 4)
    
    {
        
        if(XmlHttpObj.status == 200)
        
        {
            
            PopulateCountyList(XmlHttpObj.responseXML.documentElement);
            
        }
        
        else
        
        {
            
            alert("problem retrieving data from the server, status code: "  + XmlHttpObj.status);
            
        }
        
    }
    
}

function PopulateCountyList(countyNode)

{
    
    var region = document.getElementById("region");
    
    for (var count = region.options.length-1; count >-1; count--)
    
    {
        
        region.options[count] = null;
        
    }
    
    var countyNodes = countyNode.getElementsByTagName('county');
    var idValue;
    var textValue;
    var optionItem;
    
    for (var count = 0; count < countyNodes.length; count++)
    
    {
        textValue = GetInnerText(countyNodes[count]);
        idValue = countyNodes[count].getAttribute("id");
        optionItem = new Option( textValue, textValue,  false, false);
        region.options[region.length] = optionItem;
        
    }
    
}

function GetInnerText (node)
{
    return (node.textContent || node.innerText || node.text) ;
}

which is stored as a Javascript file, I then have this HTML

<option value="London">London</option>

<option value="Paris">Paris</option>

</select>

So when one of the options is selected (ie: Paris), a new HTML select list is loaded below containing options based on what has been selected.

The code for the HTML list which loads is

<select name="region" id="region">
<option value="">Select county</option>
</select>

This all works fine, but I wonder if anyone can help with my questions.

Basically I have a PHP session stored on the page called

$_SESSION['county']

which can store the name of one of the options, so like

$_SESSION['county'] = 'Paris';

or

$_SESSION['county'] = 'London';

So my question is, how can I provide the javascript a default "county" to load data for?

Kind of a default option.

I wonder if it's something to do with doing an "onload" within the <body> tag

Any help would be ace, i've tried to many things and cannot get it to work

Thanks

Dave

RichardRotterdam · April 25, 2010

So my question is, how can I provide the javascript a default "county" to load data for?

Kind of a default option.

I wonder if it's something to do with doing an "onload" within the <body> tag

What exactly do you mean with a default country? A default to show on your page, a default value for you session? Or perhaps something else?

Sign In

XMLHTTP Help

Recommended Posts

Canman2005

Link to comment

Share on other sites

RichardRotterdam

Link to comment

Share on other sites

Archived

Browse

Activity

Important Information