class Jekyll::FrontmatterDefaults

This class handles custom defaults for YAML frontmatter settings. These are set in _config.yml and apply both to internal use (e.g. layout) and the data available to liquid.

It is exposed via the frontmatter_defaults method on the site class.

Public Class Methods

new(site) click to toggle source

Initializes a new instance.

# File lib/jekyll/frontmatter_defaults.rb, line 9
def initialize(site)
  @site = site
end

Public Instance Methods

all(path, type) click to toggle source

Collects a hash with all default values for a page or post

path - the relative path of the page or post type - a symbol indicating the type (:post, :page or :draft)

Returns a hash with all default values (an empty hash if there are none)

# File lib/jekyll/frontmatter_defaults.rb, line 66
def all(path, type)
  defaults = {}
  old_scope = nil
  matching_sets(path, type).each do |set|
    if has_precedence?(old_scope, set['scope'])
      defaults = Utils.deep_merge_hashes(defaults, set['values'])
      old_scope = set['scope']
    else
      defaults = Utils.deep_merge_hashes(set['values'], defaults)
    end
  end
  defaults
end
ensure_time!(set) click to toggle source
# File lib/jekyll/frontmatter_defaults.rb, line 34
def ensure_time!(set)
  return set unless set.key?('values') && set['values'].key?('date')
  return set if set['values']['date'].is_a?(Time)
  set['values']['date'] = Utils.parse_date(set['values']['date'], "An invalid date format was found in a front-matter default set: #{set}")
  set
end
find(path, type, setting) click to toggle source

Finds a default value for a given setting, filtered by path and type

path - the path (relative to the source) of the page, post or :draft the default is used in type - a symbol indicating whether a :page, a :post or a :draft calls this method

Returns the default value or nil if none was found

# File lib/jekyll/frontmatter_defaults.rb, line 47
def find(path, type, setting)
  value = nil
  old_scope = nil

  matching_sets(path, type).each do |set|
    if set['values'].key?(setting) && has_precedence?(old_scope, set['scope'])
      value = set['values'][setting]
      old_scope = set['scope']
    end
  end
  value
end
update_deprecated_types(set) click to toggle source
# File lib/jekyll/frontmatter_defaults.rb, line 13
def update_deprecated_types(set)
  return set unless set.key?('scope') && set['scope'].key?('type')

  set['scope']['type'] =
    case set['scope']['type']
    when 'page'
      Deprecator.defaults_deprecate_type('page', 'pages')
      'pages'
    when 'post'
      Deprecator.defaults_deprecate_type('post', 'posts')
      'posts'
    when 'draft'
      Deprecator.defaults_deprecate_type('draft', 'drafts')
      'drafts'
    else
      set['scope']['type']
    end

  set
end

Private Instance Methods

applies?(scope, path, type) click to toggle source

Checks if a given default setting scope matches the given path and type

scope - the hash indicating the scope, as defined in _config.yml path - the path to check for type - the type (:post, :page or :draft) to check for

Returns true if the scope applies to the given path and type

# File lib/jekyll/frontmatter_defaults.rb, line 89
def applies?(scope, path, type)
  applies_path?(scope, path) && applies_type?(scope, type)
end
applies_path?(scope, path) click to toggle source
# File lib/jekyll/frontmatter_defaults.rb, line 93
def applies_path?(scope, path)
  return true if !scope.key?('path') || scope['path'].empty?

  scope_path = Pathname.new(scope['path'])
  Pathname.new(sanitize_path(path)).ascend do |path|
    if path.to_s == scope_path.to_s
      return true
    end
  end
end
applies_type?(scope, type) click to toggle source

Determines whether the scope applies to type. The scope applies to the type if:

1. no 'type' is specified
2. the 'type' in the scope is the same as the type asked about

scope - the Hash defaults set being asked about application type - the type of the document being processed / asked about

its defaults.

Returns true if either of the above conditions are satisfied,

otherwise returns false
# File lib/jekyll/frontmatter_defaults.rb, line 115
def applies_type?(scope, type)
  !scope.key?('type') || scope['type'].eql?(type.to_s)
end
has_precedence?(old_scope, new_scope) click to toggle source

Determines if a new scope has precedence over an old one

old_scope - the old scope hash, or nil if there's none new_scope - the new scope hash

Returns true if the new scope has precedence over the older

# File lib/jekyll/frontmatter_defaults.rb, line 134
def has_precedence?(old_scope, new_scope)
  return true if old_scope.nil?

  new_path = sanitize_path(new_scope['path'])
  old_path = sanitize_path(old_scope['path'])

  if new_path.length != old_path.length
    new_path.length >= old_path.length
  elsif new_scope.key? 'type'
    true
  else
    !old_scope.key? 'type'
  end
end
matching_sets(path, type) click to toggle source

Collects a list of sets that match the given path and type

Returns an array of hashes

# File lib/jekyll/frontmatter_defaults.rb, line 152
def matching_sets(path, type)
  valid_sets.select do |set|
    !set.key?('scope') || applies?(set['scope'], path, type)
  end
end
sanitize_path(path) click to toggle source

Sanitizes the given path by removing a leading and adding a trailing slash

# File lib/jekyll/frontmatter_defaults.rb, line 180
def sanitize_path(path)
  if path.nil? || path.empty?
    ""
  else
    path.gsub(/\A\//, '').gsub(/([^\/])\z/, '\1')
  end
end
valid?(set) click to toggle source

Checks if a given set of default values is valid

set - the default value hash, as defined in _config.yml

Returns true if the set is valid and can be used in this class

# File lib/jekyll/frontmatter_defaults.rb, line 124
def valid?(set)
  set.is_a?(Hash) && set['values'].is_a?(Hash)
end
valid_sets() click to toggle source

Returns a list of valid sets

This is not cached to allow plugins to modify the configuration and have their changes take effect

Returns an array of hashes

# File lib/jekyll/frontmatter_defaults.rb, line 164
def valid_sets
  sets = @site.config['defaults']
  return [] unless sets.is_a?(Array)

  sets.map do |set|
    if valid?(set)
      ensure_time!(update_deprecated_types(set))
    else
      Jekyll.logger.warn "Defaults:", "An invalid front-matter default set was found:"
      Jekyll.logger.warn "#{set}"
      nil
    end
  end.compact
end