WordPress is enormously popular; it powers some 20% of the web. Rare is the web developer who doesn't come into contact with it, even those who develop primarily in other languages. It's user-friendly, server specification-friendly, and ubiquitous.
But what if you need to interact with WordPress from the outside? It might be a cron-job, it might be a little command-line tool; you might want to export or import some content, or you might want to clean some things up. You don't have to do that in... PHP, do you?
If you'd like to do it in Ruby instead, then this library might help with some of the boilerplate.
It's a wrapper for the WordPress database, using Sequel, that gives you access to the WordPress database and all its content via a nice ORM.
You can install ruby-wpdb via RubyGems:
$ gem install ruby-wpdb
An in-depth tutorial for ruby-wpdb can be found here.
But, in brief:
With ruby-wpdb you can do simple things like get the five most recent posts:
WPDB::Post.reverse_order(:post_date).limit(5).all
Or more complicated things, like get the value of the custom field with the key "image", but only for the first post whose title consists solely of letters:
WPDB::Post.first(:post_title => /^[a-z]+$/)
.postmeta_dataset.first(:meta_key => 'image')
.meta_value
Of course, you're not limited to retrieving records, you can create them too:
post = WPDB::Post.create(:post_title => 'Test', :post_content => 'Testing, testing, 123')
And ruby-wpdb knows all about the relationship between things in WordPress — so if you want to create a new user, a post by that user, and a tag for that post, you can do so by referring to the objects alone without needing to know or care about what the actual relationships are from the perspective of the database:
author = WPDB::User.create(
:user_login => 'fred',
:user_email => 'fred@example.com'
)
term = WPDB::Term.create(:name => 'Fred Stuff')
post = WPDB::Post.create(
:post_title => 'Hello from Fred',
:post_content => 'Hello, world',
:author => author
).add_term(term, 'tag')
GravityForms is a great system for easily creating forms to capture data. But its flexibility can make querying and exporting entries difficult; querying even just a single form can often result in having to write hairy SQL queries with many self-joins.
ruby-wpdb gives you an easier insight into your forms, allowing you to treat them as though they were models of any other kind.
To make this a bit more concrete, imagine you had a contact form on your site called "Contact Form". It has four fields: "Name", "Email", "Message", and "Enquiry type".
ruby-wpdb allows you to do things like get the latest five entries to have selected "quote" as their enquiry type:
WPDB::GravityForms.ContactForm.where(:enquiry_type => 'quote').reverse_order(:date_created).limit(5).all
Or display the messages that have been sent since the start of 2013:
WPDB::GravityForms.ContactForm.where(:date_created >= Date.new(2013, 1, 1)).each do |entry|
puts "#{entry.enquiry_type} enquiry from #{entry.name} <#{entry.email}>\n"
puts entry.message
puts "---"
end
Note that you get access to all the fields of the GravityForm as though they were first-class members of an actual model, allowing you to use their values when filtering and ordering.
## Console
ruby-wpdb comes with an interactive REPL console, so you can explore a WordPress install without actually having to write any scripts.
Fire it up with:
$ ruby-wpdb console
And you can then call:
> init('mysql2://user:password@hostname/db_name')
To connect to your database.
If you find yourself connecting regularly to the same database, you can tell ruby-wpdb where to find a config file:
$ ruby-wpdb console --config-file wp-config.php
Which will remove the need to call init manually.
Once you're in the console, you can do anything you'd be able to do with ruby-wpdb normally. So to list all posts with the title 'Hello World', you could call:
> Post.where(post_title: "Hello World").all