How To Store RSS feed preference

[210163]

Hello all!

Right now I am trying to implement a function which makes it possibable for my users to save a preference on which news site they want to read news from. Check out:

http://www.newspopl.com/

-- the function is not implementede yet, as you might have guessed.

I try to store preferences through cookies. But I face a problem when I want to store the second feed url, as I only overwrite the information I added with the first feed url. Can you show how to add values to a cookie which already exists, instead of overwriting it with new information?

The function which I currently use to write my cookies is this one I found in Dreamweaver:

function writeCookie(name, value, hours) {
var expire = "";
if(hours != null)
{
expire = new Date((new Date()).getTime() + hours * 3600000);
expire = "; expires=" + expire.toGMTString();
}
document.cookie = name + "=" + escape(value) + expire;
}

Thank you very much!

 

[BabyJeffy]

Hi there.

Here are a couple of simple functions you can add to your existing one... to allow you to store multiple values (using a key/pair scheme):

<script type="text/javascript">
// existing cookie writing code
function writeCookie(name, value, hours) {
  var expire = "";
  if(hours != null)
  {
    expire = new Date((new Date()).getTime() + hours * 3600000);
    expire = "; expires=" + expire.toGMTString();
  }
  document.cookie = name + "=" + escape(value) + expire;
}

// this setter allows you to update the value of a key (or add the key/value pair if it is not already there)
function setCookieKeyData(name, key, value) {
	var data = document.cookie;
	if (data) {
		var bUpdated = false;
		var cookieKeyValueData = getCookieKeyData(name).split('|');
		for (var loop=0; loop<cookieKeyValueData.length; loop++) {
			if (cookieKeyValueData[loop].split(':')[0] == key) {
				cookieKeyValueData[loop] = key + ':' + escape(value);
				bUpdated = true;
				break;
			}
		}
		if (!bUpdated) {
			cookieKeyValueData[cookieKeyValueData.length] = key + ':' + value;
		}
		writeCookie(name, cookieKeyValueData.join('|'));
	}
}

// this getter allows you to get back the value of the key from a cookie called name
//  - returns all cookie data if no key is supplied
//  - returns null if the key supplied was not found
function getCookieKeyData(name, key) {
	if (name) {
		var data = document.cookie;
		if (key) {
			var cookieKeyValueData = unescape(data.split(name+'=')[1]).split('|');
			for (var loop=0; loop<cookieKeyValueData.length; loop++) {
				if (cookieKeyValueData[loop].split(':')[0] == key) {
					return cookieKeyValueData[loop].split(':')[1];
				}
			}
		} else {
			return unescape(data.split(name+'=')[1]);
		}
	}
	return null;
}
</script>

Create the cookie as the first step:

writeCookie('myPageCookie', '', 24);

Add in some key/value pairs of data using the setter setCookieKeyData():

setCookieKeyData('myPageCookie', 'key1', 123);
setCookieKeyData('myPageCookie', 'key2', 456);
setCookieKeyData('myPageCookie', 'key3', 'banana');

Alert the contents of specific key data using the getter getCookieKeyData():

alert(getCookieKeyData('myPageCookie', 'key1'));     // 123
alert(getCookieKeyData('myPageCookie', 'key2'));     // 456
alert(getCookieKeyData('myPageCookie', 'key3'));     // banana

The code is not bullet-proof, it ought to allow you to see how you might do this.

You should also look into JSON (which could be a better alternative - depending on your needs).

Cheers,
Jeff

[tt]Visit my blog [!]@[/!]

http://www.coderambler.com/

Visit Code Couch [!]@[/!]

http://www.codecouch.com/

[/tt]

Make sure your web page and css validates properly against the doctype you have chosen - before you attempt to debug a problem!

FAQ216-6094

 

[210163]

Thanks!

Can I store my preferences in JSON? I have no experience with it, but if I can improve my system I will try to learn it. Could you explain JSON´s benefits over my current system with cookies? Give me an outline of how it could be done?

 

[BabyJeffy]

You can google JSON any time!

Cheers,
Jeff

[tt]Visit my blog [!]@[/!]

http://www.coderambler.com/

Visit Code Couch [!]@[/!]

http://www.codecouch.com/

[/tt]

Make sure your web page and css validates properly against the doctype you have chosen - before you attempt to debug a problem!

FAQ216-6094