Thanks to a tweet by a Brisbane local (Bruce) I was continuing to mull the disconnect I have from external web traffic tracking tools. I prefer to reduce the number of requests needed to serve my users – and zero requests are always fastest.
I’ve been messing with Apache CustomLog formats to debug session and performance issues in foswiki, and so given a hammer, wondered why not apply it to more things.
Then comes Bruce’s link to Client-Side Error Logging With Google Analytics, a continuation of You Really Should Log Client-Side Errors – and I wondered…
What if I put the client error into the next user request made to the server?
the javascript:
function logError(details) {
$.cookie('clientError', details);
}
window.onerror = function(message, file, line) {
logError(file + ':' + line + '\n\n' + message);
};
$(document).ajaxError(function(e, xhr, settings) {
logError(settings.url + ':' + xhr.status + '\n\n' + xhr.responseText);
});
$.cookie('clientError', null);
the apache CustomLog settings:
#add a Client Error log
LogFormat "%h %l \"%r\" %u %t %>s %{clientError}C" clientError
CustomLog ${APACHE_LOG_DIR}/clientError_local_log clientError
and the result:
192.168.1.51 - "GET /~sven/core/pub/System/JQueryPlugin/plugins/foswiki/jquery.foswiki.js?version=2.01 HTTP/1.1" - [07/Apr/2012:16:18:26 +1000] 304 - 192.168.1.51 - "GET /~sven/core/pub/System/TwistyPlugin/jquery.twisty.js?version=1.6.0 HTTP/1.1" - [07/Apr/2012:16:18:26 +1000] 304 - 192.168.1.51 - "GET /~sven/core/bin/view/Sandbox/TestClientSideLogging HTTP/1.1" - [07/Apr/2012:16:18:31 +1000] 200 http%3A%2F%2F192.168.1.51%2F~sven%2Fcore%2Fbin%2Fview%2FSandbox%2FTestClientSideLogging%3A1%0A%0Acall_me%20is%20not%20defined 192.168.1.51 - "GET /~sven/core/pub/System/TwistyPlugin/twisty.css?version=1.6.0 HTTP/1.1" - [07/Apr/2012:16:18:32 +1000] 304 - 192.168.1.51 - "GET /~sven/core/pub/System/JQueryPlugin/plugins/livequery/jquery.livequery.js?version=1.1.1 HTTP/1.1" - [07/Apr/2012:16:18:32 +1000] 304 -
This way we get super fast, no extra traffic client error tracking.
(If someone has the apache-foo to get the right SetEnvIF or RewriteCond to only log when an error is defined, please help – I tried, but failed.)
