Class: Flexo::PluginManager

Inherits:
Object
  • Object
show all
Defined in:
lib/flexo/pluginmanager.rb

Overview

Here’s the interesting parts. This class is responsible for… Managing plugins! Who would’ve thought that…

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(mutex) ⇒ PluginManager

As usual. Set up some things. Create some arrays, some hashes, get a mutex. All that



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# File 'lib/flexo/pluginmanager.rb', line 13

def initialize(mutex)
  @manager            = Flexo::Manager.instance
  @plugins_available  = []
  @plugins_loaded     = CaselessHash.new
  @plugins_path       = @manager.config['plugin.path'].to_a

  find_plugins
end

Instance Attribute Details

#plugins_available ⇒ Object (readonly)

Returns the value of attribute plugins_available.



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# File 'lib/flexo/pluginmanager.rb', line 9

def plugins_available
  @plugins_available
end

#plugins_loaded ⇒ Object (readonly)

Returns the value of attribute plugins_loaded.



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# File 'lib/flexo/pluginmanager.rb', line 8

def plugins_loaded
  @plugins_loaded
end

Instance Method Details

#find_plugins ⇒ Object

Goes through the folders sent to initialize and looks for anything resembling a plugin. Then shove them into a hash so that we can find them later



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# File 'lib/flexo/pluginmanager.rb', line 25

def find_plugins
  @manager.logger.debug "  Going to search for plugins (in #{@plugins_path.join(',')}"
  @plugins_path.each do |dir|
    Dir["#{dir}/*.rb"].each do |file| 
      begin
        require file
      rescue => e
        @manager.logger.warn(e.message)
        next
      end
    end
    
    ObjectSpace.each_object(Class) do |klass|
      if klass < Flexo::Plugin
        @manager.logger.debug("#{klass} looks like a valid Flexo-plugin")
        unless klass::NAME
          raise PluginNameError, "The plugin hasn't specified a name!"
        end

        if @plugins_available.any? { |plugin| 
          plugin::NAME.downcase == klass::NAME.downcase }
          raise PluginConflictError, 
          "The plugin name #{klass::NAME} is already being used by another plugin."
        end
        @plugins_available << klass
        @plugins_available.uniq!
      end
    end
  end
end

#get_plugin_class(name) ⇒ Object

Find a plugin and its class by its name



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# File 'lib/flexo/pluginmanager.rb', line 57

def get_plugin_class(name)
  @plugins_available.find { |plugin| 
    plugin::NAME.downcase == name.downcase 
  }
end

#load_plugin(name) ⇒ Object

Load a plugin

Raises:



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# File 'lib/flexo/pluginmanager.rb', line 64

def load_plugin(name)
  @manager.logger.debug("Going to load plugin #{name}")
  klass = get_plugin_class(name)
  raise Flexo::PluginNotFoundError, "The #{name} plugin could not be found." unless klass

  if !@plugins_loaded.key?(klass::NAME)
    begin
      klass::DEPENDS.each do |dependency|
        if(dependency[0..4] == "ruby-")
          begin
            require dependency[5..-1]
          rescue LoadError
            raise PluginDependencyError, "Plugin requires #{dependency[5..-1]}, which can't be found"
          end
          
          next
        end
        
        dep = get_plugin_class(dependency)
        if !@plugins_loaded.key?(dep::NAME)
          load_plugin(dep::NAME)
        end
      end

      plugin = klass.new(@plugins_loaded)
    rescue Flexo::PluginError => e
      @manager.logger.error "Plugin encountered an error (#{e.class}): #{e.message}"
      @manager.logger.error e.backtrace
    rescue Flexo::PluginDependencyError => e
      @manager.logger.error e.message
      return nil
    rescue Flexo::PluginNotFoundError => e
      @manager.logger.warn e.message
      return nil
    end

    @manager.mutex { @plugins_loaded[klass::NAME] = plugin }
    @manager.logger.debug "  Loaded #{plugin.class}"
  else
    @manager.logger.debug "  Already loaded #{klass.class}"
    plugin = @plugins_loaded[klass::NAME]
  end

  plugin
end

#unload_plugin(plugin) ⇒ Object

Unloads a plugin



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# File 'lib/flexo/pluginmanager.rb', line 111

def unload_plugin(plugin)
  @manager.logger.debug "Going to unload plugin #{plugin}"
  klass = @plugins_loaded[plugin]
  @manager.mutex { @plugins_loaded.delete(plugin) }
  klass.unload

      # Every file we load ends up in $". Require checks there, and if it's there,
      # it doesn't reload the file. So to force tthe removal of the plugin,
      # we remove the class from the object space, and from the array
      @plugins_path.each do |p|
file = File.expand_path(File.join(p, "#{plugin.downcase}.rb"))
$".delete file
      end

      Object.send :remove_const, klass.name if klass
end