Santa's Helpers' Helpers (#318)

* Santa's Helpers' Helpers

* Fixes from review

---------

Co-authored-by: D Ruth Holloway <ruth@hiruthie.me>

2023/incoming/santa-s-helpers-helpers.pod

@@ -0,0 +1,142 @@
+Title: Santa's Helpers' Helpers
+Author: D Ruth Holloway <ruth@hiruthie.me>
+Topic: DBIx::Class::Helpers
+
+=encoding utf8
+
+In past years, Santa really was that jolly old soul everyone talks about, but
+for the last several months, the old boy has been roaring at his staff in
+frustration.
+
+"Eight B<billion> souls on earth now!  How am I to keep my lists? The old ways
+just aren't working any more! I can't tell who's been naughty, and who's been
+nice!"  
+
+Midyear, he finally called a meeting of the entire North Pole team, elves and
+reindeer both. Mrs. Claus baked up a massive batch of cookies, and called the
+meeting to order.  "Now, listen up, all of you! As you know, Santa has been in
+quite a state this year. The population of Earth hit 8 billion last November,
+and all those babies born since are automatically on the good list for their
+first year.  But keeping up with the older children and adults has gotten to be
+quite the burden. He's driving me crazy, stomping around the house with those
+long lists dragging around behind him. So everyone, put your thinking caps on.
+We need innovation, now!"
+
+The North Pole's CEO stood up, shuffled some papers on the lectern in front of
+him, and said, "folks, I owe you all an apology. I've been a grumpy old jerk all
+year, with my job overwhelming me at last. Mrs. Claus and I have spent some time
+talking, and she's convinced me to ask you all for your help. We need a better
+way to keep up with the lists of naughty and nice children and adults on earth.
+Don't worry about what it'll cost, I'll take care of that. But it needs to be
+fast, flexible, and easy for us to keep up with. If there are some bits of it
+that we can automate, so much the better. Does anyone have an idea we can use?"
+
+About halfway to the back sat an elf named Otto, wearing thick glasses, and a
+pocket protector. He was a builder of the geeky electronic toys that had become
+so popular in the last thirty or forty years. He raised his hand, and when Santa
+called on him, he said, "Sir, if we can get a big enough computer, we could put
+all of them in a database. Some of us could write a program to help you manage
+it on your web browser."
+
+"Elf Otto, that's a fine idea! Come up here and let's work on that. Anyone else
+knowledgeable in these things, please come down front to help.  The rest of you,
+get cracking on those toy orders!"
+
+The new North Pole Application Group, as they dubbed themselves, quickly decided
+to build Santa's new database manager with Perl, using L<Dancer2>,
+L<DBIx::Class>, and PostgreSQL, finding them quick and easy to use, and scalable
+to the size that the boss-man needed.  A couple of clever elves worked with
+Santa to find a place to host their new application, another small group started
+working on the UI, a couple of grumpy older elves took up the job of testing,
+and Otto found himself leading a team to design the database schema, and give
+the UI team the tools they needed to access it.
+
+"DBIx::Class is massive!  By itself, it can do everything we need!" one
+member of the team exclaimed, after reading just some of the documentation.
+
+"Yes, sure, it can," Otto told him, "but some of it is pretty darn arcane.  We
+need helpers."
+
+The room erupted. "But *we* are Santa's helpers!" one shouted.
+
+"Fine, fine, yes, we are," Otto said, after calming the team. "But sometimes
+helpers need helpers. This is a big, big tool we're building, and we want the UI
+and testing teams to be able to use our part of it very easily, with code they
+can read and understand and maintain in the future. The database is the core of
+the application, so it's gotta be easy to work with. Call these
+Santa's-Helpers-Helpers if you want. But DBIx::Class has a lot of helpers
+available on CPAN. Let's look for a few that can make things easier to work with
+for the other teams."
+
+And so they did.  Here are a few that they found:
+
+=over 4
+
+=item L<Test::DBIx::Class>
+
+The grumpy testing elves found this module very useful; it let them set up and
+run unit and integration tests in a known-clean enviroment. They designed the
+test fixtures and wrote tests to make sure every function behaved as it was
+supposed to.
+
+=item L<Dancer2::Plugin::DBIx::Class> and L<DBIx::Class::ResultSetNames>
+
+These two modules gave the elves easy access to all the tables of the database.
+Instead of typing long references to the name of the table to start a search,
+they just start it with the name of the table. Searches are quick and
+semantically friendly: 
+
+=begin perl
+
+   $schema->resultset('Person')->search({ ... });   # no need for this...
+   db_person->search({...})                         # when you can do this.
+
+=end perl
+
+=item L<DBIx::Class::TemporalRelations>
+
+Elf Wayne used this module to write a daily cron job for the application that
+would update the children older than one year, so Santa could start watching
+their naughty/nice ratio.  The heart of it lay in a single line of code:
+
+=begin perl
+
+   db_person->born_before($dt_1_year_ago)->update({ auto_nice => 0 });
+
+=end perl
+
+=item L<DBIx::Class::Helpers> and L<DBIx::Class::MoreHelpers>
+
+The elves found all sorts of useful search shortcuts in these two modules, like
+C<rows()> to limit the number of rows in a search for paging, and C<group_by()>
+and C<order_by()> which were handy for Santa's reports. C<is()>, C<is_not()>, and
+C<is_any()> came in very handy for boolean fields, too.
+
+=item L<DBIx::Class::Numeric>
+
+Elf Cynthia squealed with joy when she found this module on CPAN. She was
+working on the part of the application that would tally up the naughty and nice
+things that people do during the year. She discovered that once she declared a
+database field as numeric, she got baked-in methods to increment and decrement
+counters, increase or decrease counts, and even set boundary limits on them.
+
+=back 
+
+Not too much later, Santa's helpers launched V1.0 of eSanta, the application for
+the North Pole to keep track of Santa's naughty and nice lists. Santa smiled
+happily as he watched data being entered from his lists automatically. Mrs.
+Claus was thrilled, too, as Santa would be less grumpy and have more time to
+spend with her. 
+
+In the small workshop the eSanta team had set up with nice laptops, a ping-pong
+table, and whiteboards covering the walls, work on V2.0 is already well
+underway. That version will include new features to help Santa in his fall
+field-work sessions, when he goes to malls and stores and parades and talks to
+the children about what they want for Christmas. It includes a module for the
+North Pole Post Office to enter data from Santa's letters, too, though the
+now-jolly fellow insists that he must still read each and every one. As the data
+is entered, it'll be piped down to Santa's workshops so that the elves could
+build the toys to fulfil those orders, and have the bundles of toys ready for
+Santa's whirlwind delivery on December 25th!
+
+=cut