module ActionWebService # :nodoc:
module API # :nodoc:
# A web service API class specifies the methods that will be available for
# invocation for an API. It also contains metadata such as the method type
# signature hints.
#
# It is not intended to be instantiated.
#
# It is attached to web service implementation classes like
# ActionWebService::Base and ActionController::Base derivatives by using
# <tt>container.web_service_api</tt>, where <tt>container</tt> is an
# ActionController::Base or a ActionWebService::Base.
#
# See ActionWebService::Container::Direct::ClassMethods for an example
# of use.
class Base
# Action WebService API subclasses should be reloaded by the dispatcher in Rails
# when Dependencies.mechanism = :load.
include Reloadable::Subclasses
# Whether to transform the public API method names into camel-cased names
class_inheritable_option :inflect_names, true
# Whether to allow ActiveRecord::Base models in <tt>:expects</tt>.
# The default is +false+; you should be aware of the security implications
# of allowing this, and ensure that you don't allow remote callers to
# easily overwrite data they should not have access to.
class_inheritable_option :allow_active_record_expects, false
# If present, the name of a method to call when the remote caller
# tried to call a nonexistent method. Semantically equivalent to
# +method_missing+.
class_inheritable_option :default_api_method
# Disallow instantiation
private_class_method :new, :allocate
class << self
include ActionWebService::SignatureTypes
# API methods have a +name+, which must be the Ruby method name to use when
# performing the invocation on the web service object.
#
# The signatures for the method input parameters and return value can
# by specified in +options+.
#
# A signature is an array of one or more parameter specifiers.
# A parameter specifier can be one of the following:
#
# * A symbol or string representing one of the Action Web Service base types.
# See ActionWebService::SignatureTypes for a canonical list of the base types.
# * The Class object of the parameter type
# * A single-element Array containing one of the two preceding items. This
# will cause Action Web Service to treat the parameter at that position
# as an array containing only values of the given type.
# * A Hash containing as key the name of the parameter, and as value
# one of the three preceding items
#
# If no method input parameter or method return value signatures are given,
# the method is assumed to take no parameters and/or return no values of
# interest, and any values that are received by the server will be
# discarded and ignored.
#
# Valid options:
# [<tt>:expects</tt>] Signature for the method input parameters
# [<tt>:returns</tt>] Signature for the method return value
# [<tt>:expects_and_returns</tt>] Signature for both input parameters and return value
def api_method(name, options={})
unless options.is_a?(Hash)
raise(ActionWebServiceError, "Expected a Hash for options")
end
validate_options([:expects, :returns, :expects_and_returns], options.keys)
if options[:expects_and_returns]
expects = options[:expects_and_returns]
returns = options[:expects_and_returns]
else
expects = options[:expects]
returns = options[:returns]
end
expects = canonical_signature(expects)
returns = canonical_signature(returns)
if expects
expects.each do |type|
type = type.element_type if type.is_a?(ArrayType)
if type.type_class.ancestors.include?(ActiveRecord::Base) && !allow_active_record_expects
raise(ActionWebServiceError, "ActiveRecord model classes not allowed in :expects")
end
end
end
name = name.to_sym
public_name = public_api_method_name(name)
method = Method.new(name, public_name, expects, returns)
write_inheritable_hash("api_methods", name => method)
write_inheritable_hash("api_public_method_names", public_name => name)
end
# Whether the given method name is a service method on this API
def has_api_method?(name)
api_methods.has_key?(name)
end
# Whether the given public method name has a corresponding service method
# on this API
def has_public_api_method?(public_name)
api_public_method_names.has_key?(public_name)
end
# The corresponding public method name for the given service method name
def public_api_method_name(name)
if inflect_names
name.to_s.camelize
else
name.to_s
end
end
# The corresponding service method name for the given public method name
def api_method_name(public_name)
api_public_method_names[public_name]
end
# A Hash containing all service methods on this API, and their
# associated metadata.
def api_methods
read_inheritable_attribute("api_methods") || {}
end
# The Method instance for the given public API method name, if any
def public_api_method_instance(public_method_name)
api_method_instance(api_method_name(public_method_name))
end
# The Method instance for the given API method name, if any
def api_method_instance(method_name)
api_methods[method_name]
end
# The Method instance for the default API method, if any
def default_api_method_instance
return nil unless name = default_api_method
instance = read_inheritable_attribute("default_api_method_instance")
if instance && instance.name == name
return instance
end
instance = Method.new(name, public_api_method_name(name), nil, nil)
write_inheritable_attribute("default_api_method_instance", instance)
instance
end
private
def api_public_method_names
read_inheritable_attribute("api_public_method_names") || {}
end
def validate_options(valid_option_keys, supplied_option_keys)
unknown_option_keys = supplied_option_keys - valid_option_keys
unless unknown_option_keys.empty?
raise(ActionWebServiceError, "Unknown options: #{unknown_option_keys}")
end
end
end
end
# Represents an API method and its associated metadata, and provides functionality
# to assist in commonly performed API method tasks.
class Method
attr :name
attr :public_name
attr :expects
attr :returns
def initialize(name, public_name, expects, returns)
@name = name
@public_name = public_name
@expects = expects
@returns = returns
@caster = ActionWebService::Casting::BaseCaster.new(self)
end
# The list of parameter names for this method
def param_names
return [] unless @expects
@expects.map{ |type| type.name }
end
# Casts a set of Ruby values into the expected Ruby values
def cast_expects(params)
@caster.cast_expects(params)
end
# Cast a Ruby return value into the expected Ruby value
def cast_returns(return_value)
@caster.cast_returns(return_value)
end
# Returns the index of the first expected parameter
# with the given name
def expects_index_of(param_name)
return -1 if @expects.nil?
(0..(@expects.length-1)).each do |i|
return i if @expects[i].name.to_s == param_name.to_s
end
-1
end
# Returns a hash keyed by parameter name for the given
# parameter list
def expects_to_hash(params)
return {} if @expects.nil?
h = {}
@expects.zip(params){ |type, param| h[type.name] = param }
h
end
# Backwards compatibility with previous API
def [](sig_type)
case sig_type
when :expects
@expects.map{|x| compat_signature_entry(x)}
when :returns
@returns.map{|x| compat_signature_entry(x)}
end
end
# String representation of this method
def to_s
fqn = ""
fqn << (@returns ? (@returns[0].human_name(false) + " ") : "void ")
fqn << "#{@public_name}("
fqn << @expects.map{ |p| p.human_name }.join(", ") if @expects
fqn << ")"
fqn
end
private
def compat_signature_entry(entry)
if entry.array?
[compat_signature_entry(entry.element_type)]
else
if entry.spec.is_a?(Hash)
{entry.spec.keys.first => entry.type_class}
else
entry.type_class
end
end
end
end
end
end
