To use the features described, include the ib-extensions Gem in the Gemfile and use 
 
require 'ib-api' 
require 'ib/symbols' 
require 'ib/order-prototypes'
in your scripts.

Place by sending a Message

To place an order, basically a :PlaceOrder- Message has to be transmitted

> ib =  IB::Connection.current
> ib.send_message :PlaceOrder, contract: IB::Symbols::Stocks.wfc , 
                   order: Limit.order( action: :buy, size: 100, price: 22  ),
                   local_id: ib.next_local_id

TWS responses with :OpenOrder and OrderStatus messages.

The PlaceOrder message is also used to modify orders.
A new order requires an incremented :local_id. By transmitting a :PlaceOrder-Message with an unchanged :local_id the order is modified (without warning).

Place with IB::Connection-methods

To avoid unintended order-modifications, explicit calls to :place_order and :modify_order are implemented.

IB-Api provides handy IB::Connection#place_order and IB::Connection#modify_order methods.

> ib =  IB::Connection.current
> the_order =  Limit.order action: :buy, size: 100, price: 50
> the_contract = IB::Symbols::Stocks.wfc 
  # call _place_order_ and get the current _order_id
> order_id = ib.place_order the_order, the_contract 
	# adjust the order and transmit the modification 
> the_order.price = 51
> the_order.local_id = order_id
> ib.modify_order the_order, the_contract

The response is stored in IB::Connection.received.

Preview and Place

To preview the impact of an order, what_if=true is added to the :PlaceOrder- Message

> ib =  IB::Connection.current
> ib.send_message :PlaceOrder, contract: IB::Symbols::Stocks.wfc , 
                   order: Limit.order( action: :buy, size: 100, price: 22 , 
                                       what_if: true, account: 'DU1111222'),
                   local_id: ib.next_local_id

> ib.received[:OpenOrder].to_human
 => ["<OpenOrder: <Stock: WFC USD NYSE> <Order: LMT GTC buy 100.0  @ 21.0 PreSubmitted #22/1729171652 from 0/DU167349 fee 1.0>>"] 
> ib.received[:OpenOrder].first.order.init_margin.to_f              =>  54164.28 
> ib.received[:OpenOrder].first.order.equity_with_loan.to_f          => 894806.34 


> ib.send_message :PlaceOrder, contract: IB::Symbols::Stocks.wfc , 
                   order: Limit.order( action: :buy, size: 100, price: 22 , 
                                       what_if: false, account: 'DU1111222'),
                   local_id: ib.next_local_id
  <OrderState: Submitted #24/1729171653 from 2000 filled 0.0/100.0 at 0.0/0.0 why_held >  # log entry

> ib.received[:OpenOrder].to_human
 => ["<OpenOrder: <Stock: WFC USD NYSE> <Order: LMT GTC buy 100.0  @ 21.0 PreSubmitted #22/1729171652 from 0/DU167349 fee 1.0>>",
     "<OpenOrder: <Stock: WFC USD NYSE> <Order: LMT GTC buy 100.0  @ 21.0 Submitted #24/1729171653 from 2000/DU167349>>"]
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