Help with string manipulation

[SirChick]

Hey

Im having difficulty with editing a div inner html.

Im trying to split it on the

<br>

then only show the latest 4 lines but it won't work.


This is what i got:

                                var original =     function Chat(div, url) {
        this.div = div;
        this.url = url;
        this.start = new Date().getTime();

        this.start = function(lastupdate) {
            lastupdate = lastupdate ? lastupdate : new Date().getTime()
            ajaxPost(this.url, 'lastupdate='+ lastupdate, function(up) {
                return function() {
                    if (this.readyState == 4) {
                        // success
                        if(this.status == 200) {
                            var data = eval('(' + this.responseText + ')');
                        
                            // start next timer
                            up.start(data.lastupdate);
                        
                            // fill chat
                            
//STRING MANIPULATION HERE
                                var original = document.getElementById(up.div).innerHTML;
                                var index = original.indexOf('<br>') + 4;
                                var partial = original.substr(index);
                                document.getElementById(up.div).innerHTML = partial + data.html;

                    }
                        
                        // connection error
                        else {
                            // try again in .8 of a seconds
                            setTimeout(function(){
                                up.start(lastupdate);
                            }, 800);
                        }
                    }
                };
            }(this));
        };
    }
    
    var chat = new Chat('chat', 'getnewmessages.php'); 

The script works fine except trying to edit the string to only show a max amount of lines. How can i get this work ?

Please help!
Thanks

[Tcobb]

If you have a single string (like an element's innerHTML property) AND they can be parsed into lines because they have a single token/string separator such as '<br />' you can do this by running the string through a function like this:

function onlyNewStuff( numLines, innerHTMLString){
    var x = innerHTMLString.split( '<br />');
    while( x.length > numLines){
          x.shift();
     }
      x = x.join('<br />');
      return x;
}

So, if you had a div that contained all the lines, and you wanted to rid it of all but the last four lines, you would do something like this with it:

var a = document.getElementById('HTML_ID_OF_THE_DIV_TO_BE_PURGED');
a.innerHTML = onlyNewStuff(4, a);

That should do it.

[SirChick]

Thanks!

[Tcobb]

Sorry---
The last block of code should read:

var a=document.getElementById('HTML_ID_OF_THE_DIV_TO_BE_PURGED');
a.innerHTML = onlyNewStuff(4, a.innerHTML);

Sorry.