Javascript-jQuery/PHP sometimes not working.

DKY

I'm not sure exactly what is going on here or how to problem solve this but I have some code in php

ECHO "<TD WIDTH='" . $NAV_PN_ColWidth . "' style='border-left: solid #000000 1px; border-bottom: solid #000000 1px; text-align:center;'><input name='nav_pn".$EmptyRows."' type='text' id='nav_pn".$EmptyRows."' value='' size='12' style='font-family:Tahoma,Arial,Helvetica,Geneva,sans-serif; font-size:small; text-align:center; border: 0 none;' onblur='this.value=this.value.toUpperCase()'/></TD>\n";

and if someone updates the nav_pn input it will submit a new record into a MySQL database by using the following

$("#nav_pn<?php echo $JavaCnt2;?>").change(function(){
	var nav_pn     = $('#nav_pn<?php echo $JavaCnt2;?>').attr('value');	
	var username = '<?PHP ECHO $UserName;?>';	
	//alert("value=nav_pn&nav_pn="+ nav_pn + "&user=" + username)		
		$.getJSON('AJ_Update.php', {'value' : 'nav_pn', 'nav_pn' : nav_pn,'user' : username}, parseInfo);
			function parseInfo(data){}
				window.location='<?php echo $_SERVER["PHP_SELF"]."?usid=".$_GET['usid'];?>';
	}
	);

and here is my code from AJ_Update.php

	if($_GET['value'] == "nav_pn"){
		mysql_query("INSERT INTO TBLTRANSFERS (nav_pn, user, crt_ts, mod_ts, email, ext, user_id) VALUES ('".strtoupper($_GET['nav_pn'])."', '".$_GET['user']."','". $timenow ."','". $timenow ."',(SELECT b.emailaddress FROM tblusers b WHERE b.username='".$_GET['user']."'),(SELECT b.extension FROM tblusers b WHERE b.username='".$_GET['user']."'),(SELECT b.user_id FROM tblusers b WHERE b.username='".$_GET['user']."'))"); 
	}

My problem is that sometimes this works beautifully and sometimes it doesn't. I can't figure out why. When I do an alert it seems like its grabbing all the values, the only thing I can figure is that the code in the AJ_Update.php is not working for some reason. Any thoughts?

big_nerd

DKY,

I personally use FireBug, a FireFox Add-On - it has a console tab where you can see AJAX requests and the PHP output.

I would modify the AJ_Update.php:

	$debug = true; // disable when not testing
	if ($debug) { printf('<!-- &#37;s -->',print_r($_GET,true));
	if($_GET['value'] == "nav_pn"){
		mysql_query("INSERT INTO TBLTRANSFERS (nav_pn, user, crt_ts, mod_ts, email, ext, user_id) VALUES ('".strtoupper($_GET['nav_pn'])."', '".$_GET['user']."','". $timenow ."','". $timenow ."',(SELECT b.emailaddress FROM tblusers b WHERE b.username='".$_GET['user']."'),(SELECT b.extension FROM tblusers b WHERE b.username='".$_GET['user']."'),(SELECT b.user_id FROM tblusers b WHERE b.username='".$_GET['user']."'))") or die ('<!-- '.mysql_error().'-->'); 
	}

You will be able to click on the "+" when the AJAX call is made and look at the output.

Since from what I can see you arent parsing any information from the output of AJ_Update, it SHOULD be safe for customers -- however I recommend this in a test environment anyway.

You can then see what is happening.

However, VERY important note: Be sure to wrap your $_GET statements with mysql_real_escape_string() to cleanse the input, you can't trust user input.

One thing that this will alleviate is if a string has a single quote (') in it, that will definitely break your query, and using mysql_real_escape_string() will fix that for you.

Best of luck...

DKY

Okay so I have downloaded firefox and firebug (huge learning curve on both now). I'm struggling trying to figure this out. I put in your suggested php code and now have firebug opened but can't figure out where in firebug I have to go to see this output. I could use some direction specific to my situation (it helps me learn). Firebug looks like it does a lot, I feel like I'm trying to drink from a firehose here! LOL!

johanafm

If you believe your php script isn't working, error_log the query instead of only executing it. That way you can see if the code is run at all, and also inspect the actual query being executed. It's also good practice to actually see if the query was executed without errors, and if not, log the error.

As for firebug, click console and then set it to only display XHR, reload the page, and then take the actions necessary for your XHR. After that you can inspect headers sent and received along with the actual data.

Now, I don't know how you handle the response, but if you for example just set innerHTML for some element, then the HTML comments your scripts generates will show up nowhere on the page. They will of course show in firebug, but for debugging purposes it might be better to do this instead

echo '<pre>' . print_r($_GET,1) . '</pre>';

or once again, error_log it instead.

DKY

If you believe your php script isn't working, error_log the query instead of only executing it. That way you can see if the code is run at all, and also inspect the actual query being executed. It's also good practice to actually see if the query was executed without errors, and if not, log the error.

How do I 'error_log' the query? I think this may be the way to go because sometimes this works and sometimes it doesn't but when it doesn't I have javascript alert back the values and they're alerting okay but for some reason when it calls up the AJ_Update.php page the php isn't working...

As for firebug, click console and then set it to only display XHR, reload the page, and then take the actions necessary for your XHR. After that you can inspect headers sent and received along with the actual data.

I followed the instructions to no avail. I use the web page and get a blank screen in firebug.

johanafm

DKY;10976260 wrote:
How do I 'error_log' the query?

Googled it? In conjunction with php?