Class: DBus::ProxyObject

Inherits:
Object
  • Object
show all
Defined in:
lib/dbus/introspect.rb

Overview

D-Bus proxy object class

Class representing a remote object in an external application. Typically, calling a method on an instance of a ProxyObject sends a message over the bus so that the method is executed remotely on the correctponding object.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(bus, dest, path) ⇒ ProxyObject

Creates a new proxy object living on the given bus at destination dest on the given path.



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# File 'lib/dbus/introspect.rb', line 370

def initialize(bus, dest, path)
  @bus, @destination, @path = bus, dest, path
  @interfaces = Hash.new
  @subnodes = Array.new
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(name, *args, &reply_handler) ⇒ Object (private)

Handles all unkown methods, mostly to route method calls to the default interface.



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# File 'lib/dbus/introspect.rb', line 467

def method_missing(name, *args, &reply_handler)
  if @default_iface and has_iface?(@default_iface)
    begin
      @interfaces[@default_iface].method(name).call(*args, &reply_handler)
    rescue NameError => e
      # interesting, foo.method("unknown")
      # raises NameError, not NoMethodError
      raise unless e.to_s =~ /undefined method `#{name}'/
      # BTW e.exception("...") would preserve the class.
      raise NoMethodError,"undefined method `#{name}' for DBus interface `#{@default_iface}' on object `#{@path}'"
    end
  else
    # TODO distinguish:
    # - di not specified
    #TODO
    # - di is specified but not found in introspection data
    raise NoMethodError, "undefined method `#{name}' for DBus interface `#{@default_iface}' on object `#{@path}'"
  end
end

Instance Attribute Details

#bus ⇒ Object (readonly)

The bus the object is reachable via.



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# File 'lib/dbus/introspect.rb', line 364

def bus
  @bus
end

#default_iface ⇒ String

Returns The name of the default interface of the object.

Returns:

  • (String) —

    The name of the default interface of the object.



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# File 'lib/dbus/introspect.rb', line 366

def default_iface
  @default_iface
end

#destination ⇒ Object (readonly)

The (remote) destination of the object.



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# File 'lib/dbus/introspect.rb', line 360

def destination
  @destination
end

#introspected ⇒ Object

Flag determining whether the object has been introspected.



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# File 'lib/dbus/introspect.rb', line 358

def introspected
  @introspected
end

#path ⇒ Object (readonly)

The path to the object.



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# File 'lib/dbus/introspect.rb', line 362

def path
  @path
end

#subnodes ⇒ Object

The names of direct subnodes of the object in the tree.



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# File 'lib/dbus/introspect.rb', line 356

def subnodes
  @subnodes
end

Instance Method Details

#[](intfname) ⇒ ProxyObjectInterface

Retrieves an interface of the proxy object

Parameters:

  • intfname (String)

Returns:



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# File 'lib/dbus/introspect.rb', line 384

def [](intfname)
  @interfaces[intfname]
end

#[]=(intfname, intf) ⇒ ProxyObjectInterface

Maps the given interface name intfname to the given interface _intf.

Parameters:

Returns:



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# File 'lib/dbus/introspect.rb', line 392

def []=(intfname, intf)
  @interfaces[intfname] = intf
end

#define_shortcut_methods ⇒ Object

For each non duplicated method name in any interface present on the caller, defines a shortcut method dynamically. This function is automatically called when a DBus::ProxyObject is introspected.



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# File 'lib/dbus/introspect.rb', line 410

def define_shortcut_methods
  # builds a list of duplicated methods
  dup_meths, univocal_meths = [],{}
  @interfaces.each_value do |intf|
    intf.methods.each_value do |meth|
      # Module#instance_methods give us an array of symbols or strings,
      # depending on which version
      name = if RUBY_VERSION >= "1.9"
               meth.name.to_sym
             else
               meth.name
             end
      # don't overwrite instance methods!
      if dup_meths.include? name or self.class.instance_methods.include? name
        next
      elsif univocal_meths.include? name
        univocal_meths.delete name
        dup_meths << name
      else
        univocal_meths[name] = intf
      end
    end
  end
  univocal_meths.each do |name, intf|
    # creates a shortcut function that forwards each call to the method on
    # the appropriate intf
    singleton_class.class_eval do
      define_method name do |*args, &reply_handler|
        intf.method(name).call(*args, &reply_handler)
      end
    end
  end
end

#has_iface?(name) ⇒ Boolean

Returns whether the object has an interface with the given name.

Returns:

  • (Boolean) 


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# File 'lib/dbus/introspect.rb', line 445

def has_iface?(name)
  raise "Cannot call has_iface? if not introspected" if not @introspected
  @interfaces.member?(name)
end

#interfaces ⇒ Object

Returns the interfaces of the object.



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# File 'lib/dbus/introspect.rb', line 377

def interfaces
  @interfaces.keys
end

#introspect ⇒ Object

Introspects the remote object. Allows you to find and select interfaces on the object.



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# File 'lib/dbus/introspect.rb', line 398

def introspect
  # Synchronous call here.
  xml = @bus.introspect_data(@destination, @path)
  ProxyObjectFactory.introspect_into(self, xml)
  define_shortcut_methods()
  xml
end

#on_signal(name, &block) ⇒ void

This method returns an undefined value.

Registers a handler, the code block, for a signal with the given name. It uses default_iface which must have been set.



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# File 'lib/dbus/introspect.rb', line 453

def on_signal(name, &block)
  if @default_iface and has_iface?(@default_iface)
    @interfaces[@default_iface].on_signal(name, &block)
  else
    # TODO improve
    raise NoMethodError
  end
end