Class: OandaAPI::Client::NamespaceProxy

Inherits:
Object
  • Object
show all
Defined in:
lib/oanda_api/client/namespace_proxy.rb

Overview

A client proxy and method-chaining enabler.

Examples:

Example usage

client  = OandaAPI::Client::TokenClient.new :practice, token
 = client.(1234) # => OandaAPI::Client::NamespaceProxy
.get                    # => OandaAPI::Resource::Account
.orders.get             # => OandaAPI::Resource::ResourceCollection

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(client, namespace_segment, conditions) ⇒ NamespaceProxy

Returns a new instance of NamespaceProxy.

Parameters:

  • client (OandaAPI::Client)
  • namespace_segment (String)

    a segment in a resource's URI. An ordered list of segments, joined, creates a path to a resource URI.

  • conditions (Hash)

    an optional list of parameters that typically specifies conditions and filters for a resource request. A "key" or "id" is a condition that identifies a particular resource. If a key condition is included, it is extracted and added as a namespace segment. See #extract_key_and_conditions.


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# File 'lib/oanda_api/client/namespace_proxy.rb', line 31

def initialize(client, namespace_segment, conditions)
  fail ArgumentError, "expecting an OandaAPI::Client instance" unless
    client && client.is_a?(OandaAPI::Client) || client.is_a?(OandaAPI::Streaming::Client)
  fail ArgumentError, "expecting a namespace value" if namespace_segment.to_s.empty?

  @client = client
  @conditions = {}
  @namespace_segments = [Utils.pluralize(namespace_segment)]
  extract_key_and_conditions conditions
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(sym, *args) {|OandaAPI::ResourceBase| ... } ⇒ void, ...

Executes an API request and returns a resource object, or returns a clone of self for method chaining.

Yields:

Returns:


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# File 'lib/oanda_api/client/namespace_proxy.rb', line 104

def method_missing(sym, *args, &block)
  # Check for terminating method
  if [:create, :close, :delete, :get, :update, :stream].include?(sym)
    @client.execute_request sym, namespace, conditions, &block
  else
    ns = self.clone
    ns.namespace_segments << Utils.pluralize(sym)
    ns.extract_key_and_conditions args.first
    ns
  end
end

Instance Attribute Details

#conditionsHash

Returns a collection of parameters that typically specifies conditions and filters for a resource request.

Returns:

  • (Hash)

    a collection of parameters that typically specifies conditions and filters for a resource request.


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# File 'lib/oanda_api/client/namespace_proxy.rb', line 18

class NamespaceProxy
  attr_accessor :conditions, :namespace_segments

  # @param [OandaAPI::Client] client
  #
  # @param [String] namespace_segment a _segment_ in a resource's URI. An
  #   ordered list of segments, joined, creates a path to a resource URI.
  #
  # @param [Hash] conditions an optional list of parameters that typically
  #   specifies conditions and filters for a resource request. A _"key"_
  #   or _"id"_ is a condition that identifies a particular resource. If a
  #   key condition is included, it is extracted and added as a namespace
  #   segment. See {#extract_key_and_conditions}.
  def initialize(client, namespace_segment, conditions)
    fail ArgumentError, "expecting an OandaAPI::Client instance" unless
      client && client.is_a?(OandaAPI::Client) || client.is_a?(OandaAPI::Streaming::Client)
    fail ArgumentError, "expecting a namespace value" if namespace_segment.to_s.empty?

    @client = client
    @conditions = {}
    @namespace_segments = [Utils.pluralize(namespace_segment)]
    extract_key_and_conditions conditions
  end

  # Returns a deep clone of `self`.
  # @return [NamespaceProxy]
  def clone
    ns = self.dup
    ns.conditions = conditions.dup
    ns.namespace_segments = namespace_segments.dup
    ns
  end

  # Returns the namespace (URI path to a resource).
  # @return [String]
  def namespace
    "/" + @namespace_segments.join("/")
  end

  # Extracts a _key_ parameter from the arguments.
  # If a key is found, it's appended to the list namespace segments. Non-key
  # parameters are merged into the {#conditions} collection. A parameter is a
  # key if it's named ":id", or if there is only a single scalar argument.
  #
  # @example "key" parameters
  #  client  = OandaAPI::Client::TokenClient.new :practice, token
  #  account = client.account(1234)                  # 1234 is a _key_ (accountId)
  #  account.namespace                               # => /accounts/1234
  #
  #  order = account.order(instrument: "USD_JPY",
  #                              type: "market",
  #                             units: 10_000,
  #                              side: "buy").create # No key parameters here
  #
  #  position = account.position("USD_JPY").get      # USD_JPY is a key
  #
  # @param conditions either a hash of parameter values, single scalar value, or nil.
  #
  # @return [void]
  def extract_key_and_conditions(conditions)
    key =
      case
      when conditions && conditions.is_a?(Hash)
        @conditions.merge! Utils.rubyize_keys(conditions)
        @conditions.delete :id
      when conditions
        conditions
      end
    @namespace_segments << key if key
  end

  # Executes an API request and returns a resource object, or returns a
  # clone of `self` for method chaining.
  #
  # @yield [OandaAPI::ResourceBase] if the method is `:stream`.
  #
  # @return [void] if the method is `:stream`.
  #
  # @return [OandaAPI::Client::NamespaceProxy] if the method is used
  #   for chaining.
  #
  # @return [OandaAPI::ResourceBase] if the method is one of the supported
  #   _terminating_ methods (`:create`, `:close`, `:delete`, `:get`, `:update`).
  #
  # @return [OandaAPI::ResourceCollection] if the method is `:get` and the
  #   API returns a collection of resources.
  def method_missing(sym, *args, &block)
    # Check for terminating method
    if [:create, :close, :delete, :get, :update, :stream].include?(sym)
      @client.execute_request sym, namespace, conditions, &block
    else
      ns = self.clone
      ns.namespace_segments << Utils.pluralize(sym)
      ns.extract_key_and_conditions args.first
      ns
    end
  end
end

#namespace_segmentsArray<String>

Returns an ordered list of namespaces, when joined, creates a path to a resource URI.

Returns:

  • (Array<String>)

    an ordered list of namespaces, when joined, creates a path to a resource URI.


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# File 'lib/oanda_api/client/namespace_proxy.rb', line 18

class NamespaceProxy
  attr_accessor :conditions, :namespace_segments

  # @param [OandaAPI::Client] client
  #
  # @param [String] namespace_segment a _segment_ in a resource's URI. An
  #   ordered list of segments, joined, creates a path to a resource URI.
  #
  # @param [Hash] conditions an optional list of parameters that typically
  #   specifies conditions and filters for a resource request. A _"key"_
  #   or _"id"_ is a condition that identifies a particular resource. If a
  #   key condition is included, it is extracted and added as a namespace
  #   segment. See {#extract_key_and_conditions}.
  def initialize(client, namespace_segment, conditions)
    fail ArgumentError, "expecting an OandaAPI::Client instance" unless
      client && client.is_a?(OandaAPI::Client) || client.is_a?(OandaAPI::Streaming::Client)
    fail ArgumentError, "expecting a namespace value" if namespace_segment.to_s.empty?

    @client = client
    @conditions = {}
    @namespace_segments = [Utils.pluralize(namespace_segment)]
    extract_key_and_conditions conditions
  end

  # Returns a deep clone of `self`.
  # @return [NamespaceProxy]
  def clone
    ns = self.dup
    ns.conditions = conditions.dup
    ns.namespace_segments = namespace_segments.dup
    ns
  end

  # Returns the namespace (URI path to a resource).
  # @return [String]
  def namespace
    "/" + @namespace_segments.join("/")
  end

  # Extracts a _key_ parameter from the arguments.
  # If a key is found, it's appended to the list namespace segments. Non-key
  # parameters are merged into the {#conditions} collection. A parameter is a
  # key if it's named ":id", or if there is only a single scalar argument.
  #
  # @example "key" parameters
  #  client  = OandaAPI::Client::TokenClient.new :practice, token
  #  account = client.account(1234)                  # 1234 is a _key_ (accountId)
  #  account.namespace                               # => /accounts/1234
  #
  #  order = account.order(instrument: "USD_JPY",
  #                              type: "market",
  #                             units: 10_000,
  #                              side: "buy").create # No key parameters here
  #
  #  position = account.position("USD_JPY").get      # USD_JPY is a key
  #
  # @param conditions either a hash of parameter values, single scalar value, or nil.
  #
  # @return [void]
  def extract_key_and_conditions(conditions)
    key =
      case
      when conditions && conditions.is_a?(Hash)
        @conditions.merge! Utils.rubyize_keys(conditions)
        @conditions.delete :id
      when conditions
        conditions
      end
    @namespace_segments << key if key
  end

  # Executes an API request and returns a resource object, or returns a
  # clone of `self` for method chaining.
  #
  # @yield [OandaAPI::ResourceBase] if the method is `:stream`.
  #
  # @return [void] if the method is `:stream`.
  #
  # @return [OandaAPI::Client::NamespaceProxy] if the method is used
  #   for chaining.
  #
  # @return [OandaAPI::ResourceBase] if the method is one of the supported
  #   _terminating_ methods (`:create`, `:close`, `:delete`, `:get`, `:update`).
  #
  # @return [OandaAPI::ResourceCollection] if the method is `:get` and the
  #   API returns a collection of resources.
  def method_missing(sym, *args, &block)
    # Check for terminating method
    if [:create, :close, :delete, :get, :update, :stream].include?(sym)
      @client.execute_request sym, namespace, conditions, &block
    else
      ns = self.clone
      ns.namespace_segments << Utils.pluralize(sym)
      ns.extract_key_and_conditions args.first
      ns
    end
  end
end

Instance Method Details

#cloneNamespaceProxy

Returns a deep clone of self.

Returns:


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# File 'lib/oanda_api/client/namespace_proxy.rb', line 44

def clone
  ns = self.dup
  ns.conditions = conditions.dup
  ns.namespace_segments = namespace_segments.dup
  ns
end

#extract_key_and_conditions(conditions) ⇒ void

This method returns an undefined value.

Extracts a key parameter from the arguments. If a key is found, it's appended to the list namespace segments. Non-key parameters are merged into the #conditions collection. A parameter is a key if it's named ":id", or if there is only a single scalar argument.

Examples:

"key" parameters

client  = OandaAPI::Client::TokenClient.new :practice, token
 = client.(1234)                  # 1234 is a _key_ (accountId)
.namespace                               # => /accounts/1234

order = .order(instrument: "USD_JPY",
                            type: "market",
                           units: 10_000,
                            side: "buy").create # No key parameters here

position = .position("USD_JPY").get      # USD_JPY is a key

Parameters:

  • conditions

    either a hash of parameter values, single scalar value, or nil.


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# File 'lib/oanda_api/client/namespace_proxy.rb', line 77

def extract_key_and_conditions(conditions)
  key =
    case
    when conditions && conditions.is_a?(Hash)
      @conditions.merge! Utils.rubyize_keys(conditions)
      @conditions.delete :id
    when conditions
      conditions
    end
  @namespace_segments << key if key
end

#namespaceString

Returns the namespace (URI path to a resource).

Returns:

  • (String)

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# File 'lib/oanda_api/client/namespace_proxy.rb', line 53

def namespace
  "/" + @namespace_segments.join("/")
end