Sunday, September 28, 2014

Custom Error Pages

The default page when Bedrock encounters errors during the parsing of a page is error.roc and is distributed with the other core Bedrock files.  The page shows the developer the error and the contents of the page with each line numbered for easy correlation to the error reported by Bedrock.
Bedrock Error Page

You can customize the error.roc page if you'd like or replace it.  You probably don't want to spill code to users in a production environment.

To specify your own custom error page, set the BEDROCK_ERROR_LOCATION variable in the tagx.xml file to the fully qualified path of your own Bedrock file.

<scalar name="BEDROCK_ERROR_LOCATION">/var/www/html/error.roc</scalar>

Bedrock exposes the $ERROR object that has several methods you can use to report the error.

$ERROR.mesg() - the error message

$ERROR.line() - the line number where the error was encountered.

$ERROR.file() - the name of the file where the error occurred.

$ERROR.view_source() - an HTML representation of the source code.

Simple Example

This example uses the $ERROR object to display the error message, location of the error, and the file that was being processed when the error occurred.

<html>
<body>
<h1>Whoops! We're sorry, our slip is showing!</h1>
<pre>
message: <var $ERROR.mesg()>
location: <var $ERROR.line()>
file: <var $ERROR.file()>
source: <var $ERROR.view_source()>
</pre>
</body>
</html>

E-Mail Me the Error

Here's an example error page that will give the user a message and send an email to the developers notifying them of an error...I'm using the $SMTP plugin distributed with Bedrock to email the error message.

<html>
<body>
<h1>Whoops! We're sorry, our slip is showing...</h1>

<i>Thanks for your patience...our staff is on it!</i>

<plugin:SMTP localhost rlauer6@comcast.net rlauer6@comcast.net>

<null $SMTP.subject('A Bedrock Error has occurred!')>
<null $SMTP.header('Content-Type', 'text/html')>

<sink $SMTP>
An error has occurred <b><var $ERROR.file()>[<var $ERROR.line()>]</b>
<hr>
<b>REMOTE_ADDR:</b> <var $env.REMOTE_ADDR>
<b>SERVER_ADDR:</b> <var $env.SERVER_ADDR>
<hr>
<pre>
File: <var $ERROR.file()>
Line: <var $ERROR.line()>

<span style="color:red;"><var $ERROR.mesg()></span>
</pre>
</sink>

</body>
</html>

...and voila!  I get an email when an error occurs.



Saturday, September 27, 2014