Tag names case sensitive #42

Hey there,

I have kind of a strange requirement, but it makes sense for the client: tag names have to be case sensitive and a tag named Ruby is not the same as ruby.

So here's what I did:

# config/initializers/gutentag.rb

# don't normalise tag names
Gutentag.normaliser = lambda { |name| name }

# overwrite validations, so uniqueness is not case insensitive as it is the default
class TagValidations
  def self.call(klass)
    new(klass).call
  end

  def initialize(klass)
    @klass = klass
  end

  def call
    klass.validates :name, presence: true, uniqueness: true, length: {maximum: 255}
  end

  private

  attr_reader :klass
end

Gutentag.tag_validations = TagValidations

Which works fine to a certain point, but there's a nuance in MySQL. Depending on the collation of the field (which often is utf8_general_ci, which is a default in many MySQL setups I have seen), the index might be case sensitive or not. If you set a unique index, like we do at

To get it working, you have to change the collation to something that is case sensitive in MySQL (there's a whole bunch of docs about that here https://dev.mysql.com/doc/refman/5.7/en/case-sensitivity.html).

In my case, I wrote this migration:

class ChangeCollationOfGutentagTags < ActiveRecord::Migration[5.2]
  def up
    execute "ALTER TABLE `gutentag_tags` CONVERT TO CHARACTER SET UTF8 COLLATE utf8_bin"
  end

  def down
    execute "ALTER TABLE `gutentag_tags` CONVERT TO CHARACTER SET UTF8 COLLATE utf8_general_ci"
  end
end

and it now works like a charm :)

I don't know if Gutentag can do anything about this (unlikely), but at least this is documented somewhere now :)