> Hey guys, I have a web app that has a javascript front end, a php back
> end. The javascript calls the php function which queries a database,
> and sends the information from the database, in string form, back to
> the javascript, which parses the string and displays the info. This
> works great until the data returned from the php script reaches a
> strlength of about 500,000 or so. Then it doesnt return anything, or it
> returns this message.

> Code:

> D4 Date: Wed, 06 Dec 2006 21:25:45 GMT Server: Apache/2.0.52 (Unix)
> mod_ssl/2.0.52 OpenSSL/0.9.7d DAV/2 PHP/5.0.4-dev X-Powered-By:
> PHP/5.0.4-dev Keep-Alive: timeout=15, max=97 Connection: Keep-Alive
> Content-Ty 0

> here's the relevant bits of code:

> the javascript function
> Code:

> if(searchablerequest)
>                {

> postDataReturnText("./phpscripts/searchDB.php",'data='+passedstring,
> doDisplayResults);

>                        var loading = document.createElement('DIV');
>                        loading.id = "loadingdiv";
>                        loading.innerHTML = "Loading Search Results...";
>                        loading.style.width="200px";
>                        var results = document.getElementById
> ("results_div");
>                        results.appendChild(loading);

>                }

> heres the ajax function
> Code:

> function postDataReturnText(url, data, callback)
>        {
>                var XMLHttpRequestObject = false;

>                if (window.XMLHttpRequest)
>                {
>                XMLHttpRequestObject = new XMLHttpRequest();
>                }
>                else if (window.ActiveXObject)
>                {
>                XMLHttpRequestObject = new
>                 ActiveXObject("Microsoft.XMLHTTP");
>                }

>                if(XMLHttpRequestObject)
>                {
>                XMLHttpRequestObject.open("POST", url);

>                        XMLHttpRequestObject.setRequestHeader
> ('Content-Type','application/x-www-form-urlencoded');

>                XMLHttpRequestObject.onreadystatechange = function()
>                {

>                        if (XMLHttpRequestObject.readyState == 4 &&
> XMLHttpRequestObject.status == 200)
>                        {
>                        callback(XMLHttpRequestObject.responseText);
>                        delete XMLHttpRequestObject;
>                        XMLHttpRequestObject = null;
>                        }

>                }

>                XMLHttpRequestObject.send(data);
>                }
>        }

> heres the relevant bit of php code
> Code:

> while($row = mysql_fetch_array($result, MYSQL_BOTH))// add all the
> individual row info to the return string
>        {

> $feedback.=$row['CaseID'].$delimiter2.$row['CaseTitle'].$delimiter2;//for
> mail subject line

>                $color = getCrispColor($row);

>                $feedback .= $color.$delimiter2;

>                if($all_columns_flag)
>                {
>                        foreach($columnlist as $value)
>                        {
>                                if($value != "CaseHistory")
>                                {

> $feedback.=$row[$value].$delimiter2;

>                                }
>                                else $feedback.=$row['CaseID'].$delimiter2;

>                        }
>                }
>                else
>                {
>                        for($i=0;$i<$count2;$i++)
>                        {
>                                if($columns_to_display[$i] !=
> "CaseHistory")
>                                {

> $feedback.=$row[$columns_to_display[$i]].$delimiter2;
>                                }
>                                else $feedback.=$row['CaseID'].$delimiter2;
>                        }
>                }
>                $feedback.=$delimiter;

>        }
>        $n = strlen($feedback);
>        $feedback = substr($feedback,0,$n-3);

>        echo $feedback;

> and heres the javascript function that handles the php results

> Code:

> function doDisplayResults(results)
>        {

>                alert(results);

> }

> like i said when the strlength in the php is over 500,000 or so,
> nothing gets passed to doDisplayResults . And it returns pretty fast
> with nothing as the result. This leads me to believe that the there is
> a limit set somewhere in my setup that puts a block on a string return
> that large. However, I've looked and looked at my
> httpd.conf/php.ini/appcode till my eyes are bleeding. Something else
> outside my knowledge is going on here. Any suggestions for alternate
> lines of investigation i could try?

> Sincerely,

> Q