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I’m developing a web app right now and as some of you might know there is a very popular javascript command which is used for debugging. It’s invoked via console.log() and takes anything as an argument. If you use Firefox with Firebug or Safari 4 the value you pass to console.log will be printed and introspected via a debug window.

The problem is that I forget on a regular basis to remove those console.log statements. I wrote a very quick and dirty perl script which searches files with an .js extension for console.log. I put that script in the t/ folder and named it forbidden_words.t.

It works great so far and my test suite fails as soon as there is still a console.log around. I plan to extend this script to something like Test::ForbiddenWords or something where you can specify file extensions and strings (or regexes).

I couldn’t find anything like this on the CPAN, so give me a comment if you like the idea or know something better.

I managed to pack my work on code completion to a distribution and released it to the CPAN. The source code is managed on github. Use it, watch it, fork it, break it, fix it, patch it … you know the game!

Watch the demo for new features (no audio).

So what is missing?
It would be great if code completion works for chained method calls:

# DateTime
 
my $dt = DateTime->new(year => 2009);
$dt->add( months => 1)->_  # we are still a DateTime object!
 
# in a DBIC environment
 
my $rs = $schema->resultset('Foo')->_ # we get a MySchema::ResultSet::Foo

What we need is a way to define the return values of methods. Moose’s type system is not much of a help because you cannot introspect what class is behind a custom type.

I was thinking about an IntelliPerl profile which is stored in the home directory as well as in each project. Those two are merged and define method signatures and variable types.

Possible syntax:

# ~/.intelliperl
$schema isa DBIx::Class::Schema;
$rs isa DBIx::Class::ResultSet;
$dt isa DateTime;
 
method DBIx::Class::ResultSet::search returns DBIx::Class::ResultSet
 
# ~/workspace/MyApp/.intelliperl
 
$schema isa MyApp::Model::DBIC
$rs isa MyApp::Schema::ResultSet

A different approach would be to add the method signature to the POD:

 
=head2 mymethod
 
=for intelliperl
method mymethod ($dt DateTime) returns DateTime

This will make $dt inside mymethod a DateTime variable and the returned value is a DateTime object as well.

For now only TextMate is supported. See the documentation for details.

I’d love to see more Devel::IntelliPerl::Editor::s!

It is pretty hard to write a code completion script for perl since it’s hard to find out of which type a variable is. I use simple regexes and a comment to achieve this. Here is how it looks like:

It consists of a perl script which reads the current file from STDIN and gets the current line number as well as the cursor position in that line. The script is run if the cursor is behind a -> and the string before that looks like a class or a variable. If it’s a variable the script travels the lines up until it finds something like $var = Class->new, $var = new Class or # $var isa Class.

Class::MOP::Class loads that class and retrieves all method names. It also evaluates the prefix which has been entered behind the -> and displays those methods only which have the same prefix. Private methods are moved to the buttom as well as capitalized method names.

The second part of this script is embedded in TextMate. TextMate allows to define custom commands. You can define how the data shoud be rendered depending on the return value of the script. In this case STDERR is printed directly into the editor (if there is only one method left) and STDOUT is printed as tool tip.

I’d like to hear what you think about it and whether there are better / other approaches. I should probably use PPI instead of regexes to parse the document. This is one of the reasons why I did not release any code yet. Another shortcoming is speed. Especially for large classes like Catalyst or DateTime it takes a noticeable time until you get the results.

So long… I’ll keep you posted.

TextMate has a number of great bundles which help you develop in many many languages. The feature I miss most is formatting for JavaScript just like Perl Tidy does it for Perl.

I recently saw JavaScript::Beautifier in the “Recent” list on the CPAN and was wondering if I can bind it to TextMate. This is how I did it:

First of all, install it:

sudo cpan -i JavaScript::Beautifier

Next, add the command to TextMate. Open the Bundle Editor (Bundles/Bundle Editor/Show Bundle Editor).

Then select JavaScript and click on “New Command” (bottom left).

Name it “Beautifier” (or whatever you want) and paste the following in the command text field:

require_cmd js_beautify.pl 'sudo cpan -i JavaScript::Beautifier'

js_beautify.pl $TM_FILEPATH

Set the rest of the options like this:

Now you are ready to go! Open up a JavaScript document and hit Shift+Crtl+H and the current document should be formatted.

Growl is a nice notification utility for Mac OS X. There are many applications or plugins avaiable which interact with Growl (e. g. Skype, Mail, VLC etc.).

I thought it would be nice if I could redirect the catalyst debug output to it as well. Log::Dispatch has a nice appender Log::Dispatch::MacGrowl. Load Log::Dispatch as plugin in MyApp.pm (after ConfigLoader):

use Catalyst qw/-Debug
                ConfigLoader
                Log::Dispatch
                Static::Simple/;

and configure your app accordingly:

<Log::Dispatch>
	class     = MacGrowl
	name      = growl
	app_name  = MyAppGrowls
	title     = MyApp
	sticky    = 0
	min_level = notice
	format    = [%p] %m %n
</Log::Dispatch>

I cannot recommend to set min_level to info or below because this will add all start up log statements to be rendered on your screen. Kind of annoying.

Put a log statement anywhere in your code and start up your dev server. A growl notification should appear when you hit the log statement.

You can get a sample application MyAppGrowls from GitHub.

Make sure you have the following modules installed (or run perl Makefile.PL):

• Catalyst::Plugin::Log::Dispatch
• Log::Dispatch::Config
• Log::Dispatch::MacGrowl

Writing documentation is sometimes hard but inevitable. If you write code which is published on the CPAN you can always access the documentation through search.cpan.org. For those cases where you cannot publish your code on the CPAN it would be great if you had a web site like CPAN where you can access the documentation. For this reason I wrote Pod::Browser a while back. Pod::Browser is a browser for all your local modules and all the modules from the CPAN. The interface is rendered by ExtJS, a powerful JavaScript framework.

After installing Pod::Browser and running the server (pod_browser_server.pl) you should be able to access the browser via http://localhost:3000. On the right hand side of the page is a tree which contains all the modules installed on your system. The main page contains a search box where you can search the CPAN via it’s XML interface. If you open a module which is also installed on your system, the local pod will be served. Otherwise the pod is read from the CPAN. Each module has its own ExtJS tab. This allows to have multiple documents open at the same time in a single browser window. The table of contents is shown in the upper left panel.

Since this browser has been implemented as a single Catalyst controller, you can simply create an empty controller in your application and use Catalyst::Controller::POD as base class:

package MyApp::Controller::Docs;
 
  use strict;
  use warnings;
  use base 'Catalyst::Controller::POD';
  __PACKAGE__->config(
    inc        => 1,
    namespaces => [qw(Catalyst::Manual*)],
    self       => 1,
  );
  1;

This will make the documentation to your application avaiable from /docs. The pod tree will also contain all the modules which are listed in the namespaces config attribute (in this case Catalyst::Manual).

For more information on Pod::Browser and Catalyst::Controller::POD please read the documentation on the CPAN.

Warning:

If you set inc to 1 and leave the namespaces parameter blank it can take a while until all modules are indexed and presented in your browser. Be either patient or restrict the namespace to a sane subset of your modules.

I recently had to test my model which has a method which depends on DateTime->now. The problem with testing is, that the returned value will change depending on the current time.

I could have copied the logic from the model’s method but that would have made the test obsolete. Instead I choose to mock the current time and looked for a proper module on CPAN. And was lucky: Test::MockTime does just what I want:

use Test::MockTime qw(set_absolute_time);
set_absolute_time('2009-04-24T00:00:00Z');

And that’s it!

But make shure you load modules like DateTime after Test::MockTime!

I recently created a Repo at Github.com. Since I already had MacPorts up and running on my Mac I ran sudo port install git-core to install git.

Unfortunately it also installed the perl58 package which replaced Apple’s Perl. The new perl was installed to /opt/lib/perl and @INC included those directories only. All modules I had previously installed in /Library/Perl. I decided to install Perl again to have the old behaviour again.

I followed this old guide by Apple and adopted it to Perl 5.8.8.


wget ftp://ftp.cpan.org/pub/CPAN/src/perl-5.8.8.tar.gz
tar zxvf perl-5.8.8.tar.gz
cd perl-5.8.8
export LC_ALL=C
echo “export LC_ALL=C” >> ~/.bash_profile
./Configure -de -Dprefix=/usr
make
make test
sudo make install


Now I have my good old Perl back again.