Shopify/active_merchant — pull request #347 by AlexanderZaytsev (2012-04-25 11:33:17+00:00)
Title: Line item method for two checkout integration helper

A convenient way for adding line items into the form. Supports multiple line items.

```
@helper.line_item :quantity => 1, :recurrence => '1 Week'
@helper.line_item :description => 'Test Product', :price => '15.0'

assert_field 'li_1_quantity', '1'
assert_field 'li_1_recurrence', '1 Week'

assert_field 'li_2_description', 'Test Product'
assert_field 'li_2_price', '15.0'
```
Note that I'm using the official terminology as describe here:
https://www.2checkout.com/blog/knowledge-base/merchants/tech-support/3rd-party-carts/parameter-sets/pass-through-product-parameter-set/