Module: Jekyll::Hooks

Defined in:
lib/jekyll/hooks.rb

Constant Summary collapse

DEFAULT_PRIORITY = 
20
PRIORITY_MAP =

compatibility layer for octopress-hooks users

{
  :low    => 10,
  :normal => 20,
  :high   => 30,
}.freeze
NotAvailable = 
Class.new(RuntimeError)
Uncallable = 
Class.new(RuntimeError)

Class Method Summary collapse

Class Method Details

.insert_hook(owner, event, priority, &block) ⇒ Object 



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# File 'lib/jekyll/hooks.rb', line 87

def self.insert_hook(owner, event, priority, &block)
  @hook_priority[block] = [-priority, @hook_priority.size]
  @registry[owner][event] << block
end

.priority_value(priority) ⇒ Object

Ensure the priority is a Fixnum



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# File 'lib/jekyll/hooks.rb', line 61

def self.priority_value(priority)
  return priority if priority.is_a?(Integer)
  PRIORITY_MAP[priority] || DEFAULT_PRIORITY
end

.register(owners, event, priority: DEFAULT_PRIORITY, &block) ⇒ Object

register hook(s) to be called later, public API



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# File 'lib/jekyll/hooks.rb', line 54

def self.register(owners, event, priority: DEFAULT_PRIORITY, &block)
  Array(owners).each do |owner|
    register_one(owner, event, priority_value(priority), &block)
  end
end

.register_one(owner, event, priority, &block) ⇒ Object

register a single hook to be called later, internal API



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# File 'lib/jekyll/hooks.rb', line 67

def self.register_one(owner, event, priority, &block)
  @registry[owner] ||= {
    :post_init   => [],
    :pre_render  => [],
    :post_render => [],
    :post_write  => [],
  }

  unless @registry[owner][event]
    raise NotAvailable, "Invalid hook. #{owner} supports only the " \
      "following hooks #{@registry[owner].keys.inspect}"
  end

  unless block.respond_to? :call
    raise Uncallable, "Hooks must respond to :call"
  end

  insert_hook owner, event, priority, &block
end

.trigger(owner, event, *args) ⇒ Object

interface for Jekyll core components to trigger hooks



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# File 'lib/jekyll/hooks.rb', line 93

def self.trigger(owner, event, *args)
  # proceed only if there are hooks to call
  return unless @registry[owner]
  return unless @registry[owner][event]

  # hooks to call for this owner and event
  hooks = @registry[owner][event]

  # sort and call hooks according to priority and load order
  hooks.sort_by { |h| @hook_priority[h] }.each do |hook|
    hook.call(*args)
  end
end