RnSap - SAP RFC

Have you ever needed to integrate your rails Web application or API to a SAP backend server?

Have you tried to optimize some process workflow or even expose some relevant information to an internal or external website?

There have been so many occasions when I had to integrate the SAP server to the outter world... and I've been used virtually all available options out there.

This project is a way to return to the community what I have needed and built along the way.

This gem

This Gem simplifies that process of calling SAP RFC (Remote Function Call) functions, making it quick to get information back from SAP into a Ruby/Rails apps.

What you'll find here

The following function calls are available:

RFC	Function	Status
RFC_READ_TABLE	Reads an SAP table, returning the requested columns	stable
BAPI_REQUISITION_GETDETAIL	Obtains information from a Purchase Requisition	stable
BAPI_REQUISITION_GETRELINFO	Gets information from a P.Req. release strategy	stable
BAPI_TRANSACTION_COMMIT	Commits work	stable
BAPI_TRANSACTION_ROLLBACK	Rolls back work	stable
AUTHORITY_CHECK	Checks if an user has authorization for some object	stable
BAPI_REQUISITION_RELEASE_GEN	Purchase Requisition Release (strategy) header level	stable
BAPI_REQUISITION_RELEASE	Purchase Requisition Release (strategy) item level	stable

This is the list of RFCs to be added here:

RFC	Function	Status
BAPI_PO_GETDETAIL1	Gets details from a Purchase Order	WIP
BAPI_PO_GETRELINFO	Gets Release information for a PO	WIP
BAPI_PO_RELEASE	Releases a Purchase Order (Release Strategy)	pipeline
BAPI_GOODSMVT_CREATE	Posts Goods Movement	pipeline

WIP: Work in progress Pipeline: planned to be done

Background

The NetWeaver SAP RFC framework allows for C/C++ calls to SAP Remote Function Call routines, called Function Modules.

There are always some concerns when doing lib calls, as requirements are not always thought to be the same way as in Ruby.

In some scenarios, we need to have the return as class instances.

This gem carries the calls, returning Ruby-like class instances as return, that you can than use in your projects

Dependencies

This project depends on the 'nwrfc' gem, which in turn depends on Ruby ffi to make library calls.

This project also depends on the SAP NW RFC library, which is only available through the SAP connectors, which can be found at their homepage https://support.sap.com/en/product/connectors/nwrfcsdk.html.

Unfortunatelly, it's required to have SAP access and authorization to download this file.

Current development stage

I'm in a early stage development and I would deeply appreciate support from the community to implement the functionalities foreseen for this gem, as well as propose fixes to issues.

For this matter, this gem licence is MIT, therefore you can use and modify it as much as you want, as long as you do the proper reference to my gem.

RFC_READ_TABLE - Reading an SAP table

When you know where to look for, SAP will provide almost all its information through table reading. the method read_table will read the SAP table and return it as an array of objects.

Code example

The code below:

• Carries a SAP Table reading, returning the fields requested in an array of objects with the name of that table
• fields: array with SAP field names
• read_table: takes the SAP table name and which fields as arguments. The 'where' clause isn't implemented yet
• list: returns an array of Lfa1 objects, containing an attribute for each SAP field requested

Connecting to SAP
Although this example shows 'open' user, password and connection options, keep in mind you can use (since Rails 5.2) the Secrets option to securelly store data.

# declare SAP logon info and creates the connection
logon_info = { 'user' => 'user',
               'passwd' => 'password',
               # 'trace' => 2,
               'client' => '100',
               'ashost' => 'server.com',
               'sysnr' => '00' }
conn = RnSap::Sap.new(logon_info)

Reading the entire content of a table
In this example the table LFA1 (Vendor's A segment - cross company view) is read entirely, retreaving the vendor Name, its code and its country.

# declare which fields will be read from SAP
fields = %w[NAME1 LIFNR LAND1]

# list returns an array of Lfa1 objects
list = conn.read_table('lfa1', fields, [])

puts "--------  LFA1 - lista final ---------"
puts "Count: #{list.count}"

list.each do |item|
  puts( "Vendor: #{item.lifnr} / #{item.land1} / #{item.name1}")
end

Reading with filters
In this example the table MARA (Material general view) is read with the filter for Material Type (MTART) being "Raw Material" (ROH)

fields = %w[MATNR MTART MEINS]
list = conn.read_table('mara', fields, ['MATNR = "ROH"'])

puts "--------  MARA - lista final ---------"
puts "Count: #{list.count}"

list.each do |item|
  puts( "Material: #{item.matnr} / #{item.mtart} / #{item.meins}")
end

Passing additional parameters via Hash
From version 0.3.0 onwards, it's now possible to pass Hash parameters as well. The method now assumes that the entire result should be returned, but now also allows to inform from which row the result is expected (Row Skip) and how many result rows (if available) are expected (Row Count).

# ================= Reading tables - hash parameters ====================

# The 'where' clauses are passed as an array of strings
@list3 = conn.read_table({ name: 'MARA', fields: fields, clauses: ["MTART = 'ROH'"], row_skip: 1, row_count: 2 })

puts '--------  MARA - Filtered for Raw Materials - Skip: 1 row; Count: 2 rows ---------'
puts "Count: #{@list3.count}"

@list3.each do |item|
  puts("Material: #{item.matnr} / Creator: #{item.ernam}")
end

BAPI_REQUISITION_GETRELINFO - Obtain details for a Purchase Requisition

When the Purchase requisition number is already known (ex: you obtained it through reading table EBAN), the method preq_detail will provide all information related to it, including descriptions, account assignment objects (ex: cost center) and texts.