module Sequel::Plugins::HookClassMethods::ClassMethods

This adds a new hook type. It will define both a class method that you can use to add hooks, as well as an instance method that you can use to call all hooks of that type. The class method can be called with a symbol or a block or both. If a block is given and and symbol is not, it adds the hook block to the hook type. If a block and symbol are both given, it replaces the hook block associated with that symbol for a given hook type, or adds it if there is no hook block with that symbol for that hook type. If no block is given, it assumes the symbol specifies an instance method to call and adds it to the hook type.

If any before hook block returns false, the instance method will return false immediately without running the rest of the hooks of that type.

It is recommended that you always provide a symbol to this method, for descriptive purposes. It’s only necessary to do so when you are using a system that reloads code.

Example of usage:

class MyModel
 define_hook :before_move_to
 before_move_to(:check_move_allowed){|o| o.allow_move?}
 def move_to(there)
   return if before_move_to == false
   # move MyModel object to there
 end
end

Do not call this method with untrusted input, as that can result in arbitrary code execution.

# File lib/sequel/plugins/hook_class_methods.rb, line 75
def add_hook_type(*hooks)
  Model::HOOKS.concat(hooks)
  hooks.each do |hook|
    @hooks[hook] = []
    instance_eval("def #{hook}(method = nil, &block); add_hook(:#{hook}, method, &block) end", __FILE__, __LINE__)
    class_eval("def #{hook}; model.hook_blocks(:#{hook}){|b| return false if instance_eval(&b) == false}; end", __FILE__, __LINE__)
  end
end

Returns true if there are any hook blocks for the given hook.

# File lib/sequel/plugins/hook_class_methods.rb, line 85
def has_hooks?(hook)
  !@hooks[hook].empty?
end

Yield every block related to the given hook.

# File lib/sequel/plugins/hook_class_methods.rb, line 90
def hook_blocks(hook)
  @hooks[hook].each{|k,v| yield v}
end