[This is a post in my latest long-ass series.  You may want to begin at the beginning.  I do not promise that the next post in the series will be next week.  Just that I will eventually finish it, someday.  Unless I get hit by a bus.

IMPORTANT NOTE!  When I provide you links to code on GitHub, I’m giving you links to particular commits.  This allows me to show you the code as it was at the time the blog post was written and insures that the code references will make sense in the context of this post.  Just be aware that the latest version of the code may be very different.]

Last time I said that I had three things left to do for Date::Easy before it was ready for CPAN:

• Add a Time::ParseDate fallback to the ::Datetime class.
• Figure out how to handle the UTC version of datetimes.
• (Hopefully) fill out the POD.

This time, I’m reminded of the wise words of the great sage Meatloaf: two outta three ain’t bad.

Perl has a "statement modifier" form of most control structures:

EXPR if EXPR;
EXPR unless EXPR;
EXPR while EXPR;
EXPR until EXPR;
EXPR for EXPR;

Perl also has a C-style for loop:

for (INIT; COND; STEP) {
    ...
}

The curious part: COND is a normal expression, but STEP allows statement modifiers. That is, you can write:

for (my $i = 0; $i < 10; $i++ if rand() < 0.5) {
    print "$i\n";
}

This is only of interest to Mac users who link their Perl against MacPorts code, but if you are such a person, you may find this useful.

This morning I found that Perl code that used LWP::Protocol::https was failing, but only when run by the test harness.

After some flailing around I managed to track this to the fact that I had just updated MacPorts, and taken openssl from 1.0.2f_0 to 1.0.2g_0. I still do not know the precise cause of the failure, but it was exposed by the fact that the test harness (whether ExtUtils::MakeMaker or Module::Build) set PERL_DL_NONLAZY=1.

Downgrading to the old openssl did not fix the problem of course, but made the symptoms go away. The short version of the procedure is

$ sudo port activate openssl @1.0.2f_0

For details on downgrading a port, see https://trac.macports.org/wiki/howto/InstallingOlderPort

In my last YAML post I said libsyck is not maintained anymore. I had a look, and this is wrong. Even if _why does not work on it anymore, (he came back btw recently), it is maintained and made some progress in libsyck, which is not reflected in the YAML::Syck perl part.

It is a mess, I admit, but easier fixable than the YAML::XS mess. So I took libsyck upstream, which is at 0.70, and merged it with our changes which are at 0.61. Our perl-specific changes are a complete mess, so I cleaned that up to be acceptable upstream into a new 0.71.

merge back various changes from upstream (my own WIP version 0.71)

Too long/didn't read: Don't use Test::WWW::Mechanize::PSGI or similar, use LWP::Protocol::PSGI. I wish I'd found out about this module when it was first released in 2011 rather than in 2015. Which is why this article is here. LWP::Protocol::PSGI is great work and needs to be more widely known.

Since we moved away from monolithic web applications deeply embedded into the web server via the web framework movement and PSGI, now around a decade ago, a common way of testing things has been with modules like Catalyst::Test, Test::WWW::Mechanize::PSGI, Dancer2::Test and similar. These work by mocking the http request and response layers, with the mocked layers talking to an object or a subroutine reference rather than a web server. Which is fine, except, say you want to test both against your application code and your web server using the same test suite. You end up having to do fairly nasty things to decide if you are dealing with a mocked http request/response layer talking to a coderef, or a real one talking to a web server.

Fortunately LWP::Protocol::PSGI eliminates this entire problem.

We're all familiar with references and Use Rule 1:

You can always use an array reference, in curly braces, in place of the name of an array.

This leads to code like ${$foo} (dereference a scalar reference) or @{$bar{baz}} (dereference an array reference stored in a hash).

The curious part: The curly braces actually form a block, i.e. you can put multiple statements in there (just like do BLOCK), as long as the last one returns a reference:

% perl -E 'use strict; use warnings; ${say "hi"; \$_} = 42; say $_'
hi
42

This block also gets its own scope:

% perl -E 'use strict; use warnings; ${my $x = "hi"; say $x; \$x} = 42; say $x'
Global symbol "$x" requires explicit package name at -e line 1.
Execution of -e aborted due to compilation errors.

$x isn't visible outside the ${ ... } block it was declared in.

% perl -E 'use strict; use warnings; ${my $x = "hi"; say $x; \$x} = 42;'
hi

TL;DR - if you have an Alien::Base based Alien module, please update configure_requires so that it depends on Alien::Base::ModuleBuild instead of Alien::Base, and (this part is key) make a release.

This is technically more correct, and it will also future proof your module in the event that Alien::Base::ModuleBuild gets spun off from the rest of Alien::Base. There are a number of motivations making such a move. Please join us on GitHub or the #native IRC channel if are interested in working on the next generation of of Alien::Base.

Personally I'd prefer YAML over JSON for local config data anytime. Even if JSON is secure by default, and YAML is insecure. YAML is readable and writable. It's better than .ini, .json and .xml.

But Houston we have a problem. For a long time. I'll fix it.

We have the unique advantage that the spec author and maintainer is from the perl world, Ingy, and maintains the two standard libraries YAML, the PP (pure perl) variant, and YAML::XS, the fast XS variant, based on LibYAML.

This would be an advantage if those two libraries would agree on their interpretation and implementation of the specs. They do not.

Historically the YAML library is used as the default reader for CPAN .yml preferences and a fork of YAML::Tiny, CPAN::Meta::YAML which is in core is used to read and write the package META.yml files.

continuous integration using sparrow tool chain

Sparrow is a tool to automate testing infrastructure. Automated testing is essential part of continuous integration processes as it provides fast feedback on cases when something goes wrong.

Consider simple example of how sparrow could be used to build up some basic parts of your infrastructure.

web application development

We have a simple Dancer2 application we are going to deploy on development environment:

app.psgi

#!/usr/bin/env perl
use Dancer2;

get '/' => sub {
    "Hello World!"
};

dance;

Let's keep source code at git repository:

Hey everyone,

I apologize for skipping last week. Following is the p5p (Perl 5 Porters) mailing list summary for the past two weeks. Enjoy!

"The future is now thanks to science" - Clemont - Pokemon Trainer and Science Aficionado.

If you are in or around NYC next week then be part of the future. NY.pm has organized a Perl 6 Beginners Study Group and next week Saturday March 05 2016 is our second group session. Meeting details from official announcement in NY.pm mailing list:

``````
The second meeting of our New York City Perl 6 study group will be held:

Saturday, March 5, 1:00 - 3:00 pm
d.b.a.
41 First Ave
Manhattan
between East 2 and East 3 Streets
http://tinyurl.com/gphhdja

Subway: F-train to Second Ave; exit at First Ave (east) end of station

R.S.V.P: http://www.meetup.com/The-New-York-Perl-Meetup-Group/events/228790319/

Preparation for Meeting:

1. Prepare to speak for 60 seconds on one Perl 6 statement or concept you've explored since Session One. A web link to your example will be helpful.

The fourth and final installment of the Perl 6 regular expression -> grammars tutorial has hit the blog: From Regular Expressions to Grammars, Part 4

Below is the list of cpanparty first members

• Kelp 0.9071
• Dancer2 0.166001
• Mojolicious::Plugin::Vparam 1.4
• Dancer2::Plugin::Ajax 0.200001
• Dancer2::Plugin::Res 0.03
• Plack::Middleware::StackTrace::LinkedSource 0.12
• Raisin 0.63

Regards

-- Alexey

I fixed some tests in Module::Release because I supported v-strings and dev versions at the same time. Even though I don't use v-strings, the module would recognize v1.2.3_1. Andreas caught this because he does this amazing work to test CPAN breakage. John Peacock noted that version changed due to the "Lyon Compromise" from the 2014 Perl QA Hackathon. I know about the various concensuses (Olso Consensus, Berlin Consensus, Lancaster Consensus), but got no google juice on the Compromise.

In short, the Lyon Compromise is a bit more strict on version formats to trim off some tricky edge cases. John pointed me at a gist from David Golden which mentions Lyon but not Compromise.

So, I'm saying Lyon Compromise for Perl QA quite a bit. And Perl. Because keywords about version formats from the Lyon Compromise. If that's what you're looking for, I hope you find it.

(From the Sydney.PM email list, Facebook page and #australian on irc.perl.org)

• 3x Perl devs wanted - http://www.seek.com.au/job/30433975
• Staples also - https://www.facebook.com/sydneypm/posts/10153984353853829 (posted by their people on sydney pm facebook)

Disclaimer: I am not involved with the above at all. I cant answer questions or provide additional information either.

My pull request challenge assignment for the month of February was Proc::ProcessTable a Perl module to interface with the Unix process table. As you can see from looking at the README.md file via Github this project recently has been moved to Github with the intention of light maintenance with focus on critical fixes made by the community. I was running out of time and I didn't have a linux system to use or test this module so I decided to do something simple like integrating Travis CI.

All it takes to enable Travis CI in a Github repo is a .travis.yml file in the root directory of the project and a Github account to allow Travis access to the Github repositories for Travis builds.

Here's a sample of the Travis file and the Travis Builds from my pull request.

As you can see from the examples Proc::ProcessTable is now tested on 8 different versions of Threaded Perl running on Ubuntu Linux. Now I can mark my February assignment as done. YAY!!!! \o/

For more information on Travis setups read the Travis Perl Docs and for further information on how to enable testing on Threaded versions of Perl please review Travis-Perl-Helpers README documentation.

Not long time ago I asked a community about possible service to run integration tests for existed cpan modules , not having too much feedback I decided to run such a service to make my suggestion visible and available to try for other users.

So, meet CPANParty - an alternative integration tests for cpan modules. Right now service is hosted on swatpm site, but in the future I will probably move it to dedicated domain.

Only a few randomly chosen cpan modules was picked up and tested. Eventually I will add more.

So, questions, ideas, issues?

Please comment here or to https://github.com/melezhik/cpanparty

Thanks in advance

Alexey Melezhik

PS CPANParty reports page below

On behalf of the Rakudo development team, I'm very happy to announce the February 2016 release of Rakudo Perl 6 #96. Rakudo is an implementation of Perl 6 on the Moar Virtual Machine

This release implements the 6.c version of the Perl 6 specifications. It includes bugfixes and optimizations on top of the 2015.12 release of Rakudo, but no new features.

Upcoming releases in 2016 will include new functionality that is not part of the 6.c specification, available with a lexically scoped pragma. Our goal is to insure that anything that is tested as part of the 6.c specification will continue to work unchanged. There may be incremental spec releases this year as well.

The tarball for this release is available from http://rakudo.org/downloads/rakudo/.

Please note: This announcement is not for the Rakudo Star distribution[^1] --- it's announcing a new release of the compiler only. For the latest Rakudo Star release, see http://rakudo.org/downloads/star/.

For the past year I’ve been working on putting a new business together that is built on top of Perl and AngularJS. The new business is called Tabletop.Events. It is a convention management platform for the hobby board game industry. 

It’s features include:

• Badge sales and printing
  
• User event submissions
• Event ticket sales
• Registration desk management
• Blog and email newsletter to attendees
• Desktop and mobile friendly interfaces
• A full web service API

It’s built on Wing, which is the same core toolkit we used to build The Game Crafter. On the back-end, Wing is pure Perl making use of Dancer, DBIx::Class, Moose, and a whole host of other Perl technologies. On the front-end Wing is all AngularJS, which allows us to rapidly build out a robust UI that automatically ties itself to the Perl backend.

If you want to learn more about the technologies used to make Tabletop.Events, come hang out with us at the next MadMongers meeting.