Editing Variable-Length Line Item Edits (section)

=== Edit form ===

* The edit form markup will include the `.line-item` element. 
* The flattened display of the line item will be replaced in its entirety with the edit form markup.
* The edit form will be replaced in its entirety with the updated flattened display of the line item once editing has been completed.
* The edit form will include the following variables as hidden form elements:
** `class`: Name of PHP class that handles line item edits.
** `id`: Line item record id, if editing an existing line item record.
** `pid`: The record id of the parent record that the line item is linked to, if editing a new line item record.*