Fmedit

A small library for manipulating the frontmatter in markdown files.

It assumes that the frontmatter is deliniated by --- and in YAML format.

Fair warning: it worked when I used it but tests are… non existant. I assume you will be using it on version controlled files that can be easily compared and restored.

Install the gem and add to the application's Gemfile by executing:

$ bundle add fmedit

If bundler is not being used to manage dependencies, install the gem by executing:

$ gem install fmedit

There's no CLI (yet?) but this provides a little utility library for writing scripts to manipulate the frontmatter in markdown files.

For example, to add the "published" attribute to all your posts and save them:

require "fmedit"

Fmedit::Files.new("src/_posts/*") do |file|
    file.edit! published, true
    file.save!
end

To unpublish all hidden posts, and remove the hidden attribute:

require "fmedit"

Fmedit::Files.new("src/_posts/*") do |file|
  file.add "published", false if f.get("hidden")
  file.remove "hidden"
end

Fmedit::Files.new takes a directory wildcard as a argument, e.g. "src/_posts/*". It requires a block to be passed, to which an instance of Fmedit::Editor will be passed.

The following operations can be performed:

add: Add a key/value pair only if it doesn't already exist

add!: Add a key/value pair even if one exists (overwrites it)

edit: Update a key if the value matches a regex. Replaces using regex groups. This is the most complex operation and allows you to use regular expressions to match values, then use those groups for the replacement. Uses String#gsub under the hood.

file.edit "image", /^((?!images\/.+|\/|http).*)$/, "/images/\\1"
file.edit "image", /^(images\/.+)$/, "\/\\1"

remove: Remove a key, if it exists

get: Get the value of a key

print: Print the contents of the frontmatter

save!: Save the file

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/ideasasylum/fmedit. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

The gem is available as open source under the terms of the MIT License.

Everyone interacting in the Fmedit project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.