Class: Rack::RPC::Operation

Inherits:

Object

• Object
• Rack::RPC::Operation

show all

Defined in:

lib/rack/rpc/operation.rb

Overview

Instance Attribute Summary (collapse)

• - (Object) context readonly

Class Method Summary (collapse)

• + (Range) arity

  Returns the arity range for this operation class.

• + execute { ... }

  Defines the #execute instance method.

• + operand(name, type = Object, options = {})

  Defines an operand for this operation class.

• + (Hash{Symbol => Hash}) operands

  Returns the operand definitions for this operation class.

• + prepare { ... }

  Defines the #prepare instance method.

Instance Method Summary (collapse)

• - execute abstract

  Executes this operation.

• - (Operation) initialize(args = []) constructor

  Initializes a new operation with the given arguments.

• - prepare abstract

  Prepares this operation.

• - (Array) to_a

  Returns the array representation of the arguments to this operation.

• - (Hash) to_hash

  Returns the hash representation of the arguments to this operation.

• - (String) to_json

  Returns the JSON representation of the arguments to this operation.

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# File 'lib/rack/rpc/operation.rb', line 103

def initialize(args = [])
  case args
    when Array then initialize_from_array(args)
    when Hash  then initialize_from_hash(args)
    else case
      when args.respond_to?(:to_args)
        initialize_from_array(args.to_args)
        @__context__ = args.context if args.respond_to?(:context)
      else raise ArgumentError, "expected an Array or Hash, but got #{args.inspect}"
    end
  end

  initialize! if respond_to?(:initialize!)
end

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# File 'lib/rack/rpc/operation.rb', line 96

def context
  @context
end

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# File 'lib/rack/rpc/operation.rb', line 79

def self.arity
  @arity ||= begin
    if const_defined?(:ARITY)
      const_get(:ARITY)
    else
      min, max = 0, 0
      operands.each do |name, options|
        min += 1 unless options[:optional].eql?(true)
        max += 1
      end
      Range.new(min, max)
    end
  end
end

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# File 'lib/rack/rpc/operation.rb', line 53

def self.execute(&block)
  self.send(:define_method, :execute) do
    begin
      before_execute if respond_to?(:before_execute)
      result = instance_eval(&block)
      after_execute if respond_to?(:after_execute)
      result
    rescue Exception => error
      after_error(error) if respond_to?(:after_error)
      raise
    end
  end
end

class Multiply < Operation
  operand :x, Numeric
  operand :y, Numeric
end

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# File 'lib/rack/rpc/operation.rb', line 21

def self.operand(name, type = Object, options = {})
  raise TypeError, "expected a Class, but got #{type.inspect}" unless type.is_a?(Class)
  operands[name.to_sym] = options.merge(:type => type)
end

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# File 'lib/rack/rpc/operation.rb', line 71

def self.operands
  @operands ||= {}
end

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# File 'lib/rack/rpc/operation.rb', line 31

def self.prepare(&block)
  self.send(:define_method, :prepare) do
    begin
      begin
        before_prepare if respond_to?(:before_prepare)
        instance_eval(&block)
      ensure
        after_prepare if respond_to?(:after_prepare)
      end
      self
    rescue Exception => error
      after_error(error) if respond_to?(:after_error)
      raise
    end
  end
end

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# File 'lib/rack/rpc/operation.rb', line 192

def execute
  raise NotImplementedError, "#{self.class}#execute"
end

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# File 'lib/rack/rpc/operation.rb', line 183

def prepare
  self
end

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# File 'lib/rack/rpc/operation.rb', line 200

def to_a
  self.class.operands.inject([]) do |result, (param_name, param_options)|
    result << instance_variable_get("@#{param_name}")
    result
  end
end

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# File 'lib/rack/rpc/operation.rb', line 211

def to_hash
  self.class.operands.inject({}) do |result, (param_name, param_options)|
    result[param_name] = instance_variable_get("@#{param_name}")
    result
  end
end

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# File 'lib/rack/rpc/operation.rb', line 222

def to_json
  to_hash.to_json
end