NAME JavaScript::XRay - See What JavaScript is Doing VERSION Version 0.97 SYNOPSIS I put the comments in for lazy folks like myself who cut and page the Synopsis before they thoroughly read the pod. #!/usr/bin/perl use strict; use warnings; use JavaScript::XRay; # HTML page with a
tag and hopefully some JavaScript # if you're using this module :) my $html_page = do { local $/; <> }; # the 'alias' is the prefix which all your switches will be # prefixed with and helps "scope" the injected JavaScript # variables and functions so they don't collide with # anything in your page. my $alias = 'jsxray'; # jsxray is the default # switches is just a hash ref that could be build for # incoming parameters on a query string or passed # via options via a command line script # In the future, hooks may be built for building the # switches for popular frameworks. The idea is that you # want to look through the incoming param list and pass # anything that matches your alias. This interface isn't # the cleanest, but just wanted to make it generic. It # can definitely be improved... # via CGI.pm # my $q = CGI->new; # my $switches = { # map { $_ => $q->param($_) } # grep { /^$alias/ } $q->param # }; # via mod_perl # my $req = Apache::Request->new($r); # my $switches = { # map { $_ => $req->param($_) } # grep { /^$alias/ } $req->param # }; # Catalyst # my $req = $c->request; # my $switches = { # map { $_ => $req->param($_) } # grep { /^$alias/ } $req->param # }; # or just hard coded to get something to work my $switches = { $alias => 1 }; # now we only want to filter if its turned on so we can # you may want put your switch building inside this # conditional as well and just check for your alias # ATTENTION - also if enable filtering in your # production environment, maybe have special cookie # that needs to be set as well in order to enable # filtering. (so Joe Somebody or Ex-Employee can't # turn it on) if ( $switches->{$alias} == 1 ) { my $js_xray = JavaScript::XRay->new( alias => $alias, switches => $switches, ); $html_page = $js_xray->filter($html_page); } print $html_page; DESCRIPTION JavaScript::XRay is an HTML source filter. It was developed as a tool to help figure out and debug large JavaScript frameworks. The main idea is that you hook it into your application framework and give you the ability to 'flip a switch' an inject a JavaScript function tracing console into your out going page. Some of the things it does... * Injects an IFrame logging console It finds the body tag in the document and injects the IFrame just after it along with all the JavaScript to drive it. It also provides you with a logging function with the same name as your alias (defaults to jsxray) jsxray("Hi there"); * Scans HTML for JavaScript functions For each function it finds it inserts a call to this method which logs the function call along with the value of the function arguments. function sum ( x, y ) { becomes function sum ( x, y ) { jsxray( "sum( " + x + ", " + y + " )" ); so now any call this function and its arguments will get logged to the IFrame. * Switches to limit what you log You can manually skip specific functions, choose to see only functions you specify, or filter functions matching a specified string. ( see "Switches" ) * Provide execution counts Provides a method to see how often your functions are being called. This can be helpful to target which functions to refactor to increase performance. * Inlines external JavaScript files If external javascript files are referenced, they can be inlined so they'll be filtered as well. * Save the log for later. You can cut and paste the IFrame to a text file to analyze later by hand or munge the results with perl. Extremely helpful in moments when you have a lot of code executing and your just trying to get a handle on what's happening. Switches The module's initial design was for it to be used via a query string and the switches evolved from there. (In other words, if this switch interface feels clunky, that's the reason why) Also not the below examples use the alias 'jsxray' but if you use a custom alias, the URLs with change accordingly. * uncomment ( string1, string2, ... ) Uncomment lines prefix with these strings. Helpful with injecting timing code, or more specific debugging code. You can deploy commented logging code to production and turn it on when your turn on filtering. Extremely helpful when diagnosing problems you can't reproduce in your development environment. http://someurl/somepage?jsxray=1&jsxray_uncomment=DEBUG1,DEBUG3 will turn this... //DEBUG1 jsxray("Hey this is debug1"); //DEBUG2 jsxray("Hey this is debug2"); //DEBUG3 jsxray("Hey this is debug3"); into this jsxray("Hey this is debug1"); //DEBUG2 jsxray("Hey this is debug2"); jsxray("Hey this is debug3"); * anon (bool) Include filtering of anonymous functions. http://someurl/somepage?jsxray=1&jsxray_anon=1 * no_exec_count ( bool ) Don't inject code that keeps track of how many times a function was called. http://someurl/somepage?jsxray=1&jsxray_no_exec_count=1 * only ( function1, function2, ... ) Only filter comma separated list of functions (function1,function2,...) http://someurl/somepage?jsxray=1&jsxray_only=processData,writeTopage * skip ( function1, function2, ... ) Skip comma separated list of functions http://someurl/somepage?jsxray=1&jsxray_skip=formatNumber * skip ( /^string/ ) Only filter function that match string http://someurl/somepage?jsxray=1&jsxray_filter=ajax CONSTRUCTOR JavaScript::XRay->new( %hash ); Create a new instance with the following arguments * alias Think of this as a JavaScript namespace. All injeted JavaScript functions and variables are prefixed with this alias to avoid colliding with any code that currently exists on your page. It also is the prefix used for all the switches to toggle things on and off. * switches Hash reference containing switches to change filtering behavior. See the "Switches" section for more details. * iframe_height The height of your logging IFrame, defaults to 200 pixels. * css_inline Change the style of the logging IFrame via inline CSS. * css_external Change the style of the logging IFrame via an external stylesheet. METHODS $jsxray->filter( $html ); Pass HTML in, get modified HTML out. INLINING EXTERNAL JAVASCRIPT One of the short comings of this module is that many people put their javascript in seperate file and reference them via the src attribute I have all the code in place to inline the src attribute, but only have the src =~ /^http/ handler working now. Still working out the details on how to handle inlining the others. AUTHOR Jeff Bisbee, "