Class: RTM::Engine

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# File 'rtm/lib/rtm/engine.rb', line 5

def self.abstract?
  self == Engine
end

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# File 'rtm/lib/rtm/engine.rb', line 13

def self.add(engine)
  @engines ||= []
  @engines << engine
end

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# File 'rtm/lib/rtm/engine.rb', line 28

def self.all
  @engines ||= []
  @engines.reject!{|e| e.abstract?} # this needs to be done here because in the inherited hook the method is not yet available.
  @engines
end

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# File 'rtm/lib/rtm/engine.rb', line 90

def self.connect(*args)
  self.new(*args)
end

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# File 'rtm/lib/rtm/engine.rb', line 82

def self.default
  if RUBY_PLATFORM =~ /java/
    :ontopia
  else
    :activerecord
  end
end

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# File 'rtm/lib/rtm/engine.rb', line 67

def self.detect(preferred=nil)
  if preferred # return the users preference, if given
    implementation = preferred
  elsif engine_name = ENV['RTM_BACKEND'] || ENV['RTM_IMPLEMENTATION'] || ENV['RTM_ENGINE'] # inspect system environment (several alternatives)
    implementation = engine_name.to_sym
  elsif implementation = self.list.first # check if one is already loaded
    warn("No engine implementation was specified for RTM.connect. Using the first already loaded engine (#{implementation.inspect}).")
  else
    implementation = self.default # use hardcoded default
    warn("No engine implementation was specified for RTM.connect. Choosing default (#{implementation.inspect}).")
    implementation
  end
  implementation
end

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# File 'rtm/lib/rtm/engine.rb', line 18

def self.identifier(i=nil)
  if i
    # setter / declaration
    @identifier = i
  else
    # getter
    @identifier
  end
end

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# File 'rtm/lib/rtm/engine.rb', line 9

def self.inherited(subclass)
  Engine.add(subclass) # this MUST be Engine and not self! Otherwise every intermediate class in the inheritance chain will have it's own list
end

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# File 'rtm/lib/rtm/engine.rb', line 34

def self.list
  all.map{|e| e.identifier}
end

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# File 'rtm/lib/rtm/engine.rb', line 42

def self.load(engine_name)
  engine_gem_name = engine_name
  engine_gem_name = engine_name.to_s.split("_").first if engine_gem_name.to_s =~ /_/
  unless Object.const_defined?("Gem") && rtmgem = Gem.loaded_specs["rtm"]
    engine_path = File.expand_path(File.join(File.dirname(__FILE__), "../../../rtm-#{engine_gem_name}/lib"))
    $LOAD_PATH.unshift engine_path if File.directory?(engine_path)
  end
  require "rtm/#{engine_gem_name}"
  self[engine_name]
end

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# File 'rtm/lib/rtm/engine.rb', line 53

def self.load!(engine_name=nil)
  engine_name = self.detect unless engine_name
  unless list.include?(engine_name)
    warn("Requested engine '#{engine_name}' not loaded. Trying to autoload it.")
    engine = load(engine_name)
    if list.include?(engine_name)
      warn("Autoloading '#{engine_name}' was successful")
    else
      raise "Autoloading '#{engine_name}' failed. Make sure rtm-#{engine_name} exists and is installed or require it manually."
    end
  end
  engine || load(engine_name)
end

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# File 'rtm/lib/rtm/engine.rb', line 101

def identifier
  self.class.identifier
end