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September 29, 2006

saprfc Ruby on Rails with AJAX

Since I wrote an article about integration of SAP and Ruby on Rails, it has been great to see the beginnings of a kernel of interest. As a result I decided to package up the sap4rails code and distribute it properly on RAA.

Rails and AJAX

One of the interesting things that Ruby on Rails provides is built AJAX functionality by virtue of an API over prototype, and Scriptalicious. In this blog, I would like to show how neatly this integration is implemented in RubyOnRails, using a simple example of Locking, and Unlocking SAP R/3 user accounts.

Installation Requirements

For this example you will need to do your own install of Ruby On Rails. Use the instructions for installing Ruby, Ruby On Rails, the RFCSDK, and saprfc in the RadRails blog.
Just be sure to install versions Ruby 1.8.4+ and Rails 1.1.2+.
Once you have got this far, the last thing to install is sap4rails. You can either install the source package or download the gem, and install this with:
gem install sap4rails-<version>.gem


For this example, most of the standard BAPIs are adequate. We need to be able to list users, with their details, including their lock state. We also need to be able to lock and unlock them.
The general functionality of the application is to create two lists of users on a page - locked and unlocked - and for you to be able to drag a user from one to the other to change their lock state in SAP.

The following RFCs are used:

BAPI_USER_GETLIST is not quite enough. This, I have had to wrap in another function module and also modify the results table to include the lock status information of users.
Create a new function module called Z_BAPI_USER_GETLIST, and make sure that you activate it for RFC on the attributes tab (in SE37) (code).
Create a new structure called ZBAPIUSNAME, and include the two structures BAPIUSNAME, and USLOCK like this .
Make sure that you activate the structure.

The code and interface needs to be completed like this:

*"*"Local Interface:
  userlist like bapiusname occurs 0 with header line.

  refresh userlistlock.

      MAX_ROWS              = 0
      WITH_USERNAME         = with_username
      ROWS                  = rows
      SELECTION_RANGE       = selection_range
      SELECTION_EXP         = selection_exp
      USERLIST              = userlist
      RETURN                = return

  loop at userlist.
    move-corresponding: userlist to userlistlock.
    if userlistlock-firstname = space.
       userlistlock-firstname = userlistlock-username.

        USER_NAME                 = userlist-username
        LOCKSTATE                 = lockstate
        USER_NAME_NOT_EXIST       = 1
        OTHERS                    = 2

    move-corresponding: lockstate to userlistlock.
    append userlistlock.



Activate the function module and test it.

The Rails part

The full application can be downloaded from here - but what I'd like to do is quickly describe the meat of what had to be done to get this type of application working.

Config - sap.yml

As described in the RadRails blog, you need to adjust the configuration in config/sap.yml to point to your SAP system:

  sysnr: "00"
  client: "010"
  user: developer
  passwd: developer
  lang: EN
  trace: "1"

Model - sap_user.rb

The SapUser object now inherits from the new SAP4Rails::Base class. This serves to automatically take care of managing RFC connections based on the config done above. The two main class methods for use are function_module, which allows you to declare what RFCs you want to use, and parameter which is a helper method for declaring attributes of a SapUser (or any other Model object).
In the interests of simplifying the application, by reducing the amount of ABAP code to be written, and the number of RFC calls to be made, I have in a way "cheated", with the arrangement of methods defined in SapUser. Instead of having a SapUser#find method, I rely on the use of SapUser#find_all and SapUser#find_cache to reduce a series of SapUser searches down to one RFC call only. In reality this is probably not good practice, but it suits for this example.

Read the code comments below for further details:

require_gem "sap4rails"

class SapUser < SAP4Rails::Base

# You must define a list of RFCs to preload
  function_module :Z_BAPI_USER_GETLIST,

# You must define a list of attribute accessors to preload
  parameter :last, :first, :userid, :locked

# do your attribute initialisation for each SapUser instance
	def initialize(last, first, userid, locked)
	  @last = last
	  @first = first
	  @userid = userid
	  @locked = locked
	  @changed = false

# what is the lock state
	def locked?
	  return self.locked ? true : false

# on #save - flip the lock state of the SapUser, calling the 
# appropriate RFC to do it
  def save()
    RAILS_DEFAULT_LOGGER.warn("[SapUser]#save what did we get: " + self.inspect)
    if self.locked?
      SapUser.BAPI_USER_LOCK.username.value = self.userid
      SapUser.BAPI_USER_UNLOCK.username.value = self.userid

    # just so something happens ...
    return true

# one RFC call to get them all
  def self.find_all
    RAILS_DEFAULT_LOGGER.warn("[SapUser]#find_all ")
    SapUser.Z_BAPI_USER_GETLIST.with_username.value = 'X'
    users = []
    SapUser.Z_BAPI_USER_GETLIST.userlistlock.rows().each {|row|
		  next if row['FIRSTNAME'].strip.length == 0
		  state = nil
		  if row['WRNG_LOGON'] == "L" || 
                     row['LOCAL_LOCK'] == "L" || 
                     row['GLOB_LOCK'] == "L"
		    state = true
		    state = false
    return users

# find a user base on the results of a SapUser#find_all
  def self.find_cache(user, cache)
    RAILS_DEFAULT_LOGGER.warn("[SapUser]#find_cache: #{user} ")
	  return row if user.strip == row.userid.strip

# get a list of all the locked users
  def self.find_locked
    RAILS_DEFAULT_LOGGER.warn("[SapUser]#find_locked ")
    locked = []
	  locked.push(user) if user.locked
    return locked

# get a list of all the unlocked users
  def self.find_unlocked
    RAILS_DEFAULT_LOGGER.warn("[SapUser]#find_unlocked ")
    unlocked = []
	  unlocked.push(user) unless user.locked
    return unlocked

Controller - lock_controller.rb

There are only 3 basic actions to the only controller in this application. The initial list action, build the starting page presenting the two lists of users (locked and unlocked). From there, as a result of the AJAX enabled calls from the dragndrop feature, two further actions are called - set_locked and set_unlocked.

class LockController < ApplicationController

# gnerate the starting user lists, and hand off to the default list view
  def list
    RAILS_DEFAULT_LOGGER.warn("[LIST] Parameters: " + @params.inspect)
    @locked_users = SapUser.find_locked()
    @unlocked_users = SapUser.find_unlocked()
    RAILS_DEFAULT_LOGGER.warn("[LIST] of Locked: " + @locked_users.inspect)
    RAILS_DEFAULT_LOGGER.warn("[LIST] of UNLocked: " + @unlocked_users.inspect)

# check through the list of locked users in the locked sortable_element box
# and set their locked state in necessary
# on completion - render the partial locked_users
  def set_locked
    RAILS_DEFAULT_LOGGER.warn("[SET_LOCKED] Parameters: " + @params.inspect)
    @locked_users = []
    cache = SapUser.find_all()
    if @params['locked_box']
      @params['locked_box'].each {|locked|
	  next if locked.length == 0
          user = SapUser.find_cache(locked, cache)
	  next if user.first.strip.length == 0
	  if user && ! user.locked?
  	    user.locked = !user.locked?
    render :partial => 'locked_users', :object => locked_users

# exact opposite/the same as set_locked
  def set_unlocked
    RAILS_DEFAULT_LOGGER.warn("[SET_UNLOCKED] Parameters: " + @params.inspect)
    @unlocked_users = []
    cache = SapUser.find_all()
    if @params['unlocked_box']
      @params['unlocked_box'].each {|unlocked|
	  next unless unlocked.length > 0
	  user = SapUser.find_cache(unlocked, cache)
	  next if user.first.strip.length == 0
	  if user && user.locked?
	    user.locked = !user.locked?
    render :partial => 'unlocked_users', :object => unlocked_users

# called by the rendering action of the partial locked_users
  def locked_users
    RAILS_DEFAULT_LOGGER.warn("[LOCKED_USERS] of Locked: " + @locked_users.inspect)

# called by the rendering action of the partial unlocked_users
  def unlocked_users
    RAILS_DEFAULT_LOGGER.warn("[UNLOCKED_USERS] of UNLocked: " + @unlocked_users.inspect)



The the overall page template (layout) defines the shape of the page, and what JavaScript libraries are pulled in for the effects (AJAX). All pages inherit from this.


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
<html xmlns="http://www.w3.org/1999/xhtml">
    <meta http-equiv="Content-type" content="text/html; charset=utf-8" />
    <title>User Administration:  <%= controller.controller_name %></title>
    <meta http-equiv="imagetoolbar" content="no" />
    <%= stylesheet_link_tag "administration.css" %>
    <%= javascript_include_tag "prototype", "effects", "dragdrop",
                       "controls" %>

  <div id="container">
    <div id="header">
    <div id="info">
      <%= link_to "home", :controller=> "/lock", :action => 'list' %>
      <h1><%= link_to "UserAdmin - #{controller.controller_name}", :controller => "/lock" %>
    <div id="content">
      <h2><%= @page_heading %></h2>
      <%= @content_for_layout %>


The two most important things in list are the two container div tags - unlocked_box and locked_box. These in turn, have a corresponding partial (unlocked_users, and locked_users), that are responsible for generating the dragable user items.

<% @heading = "User Admin - Lock/UnLock" %>

  <div id="user-admin">
    <div id="unlocked" class="dropbox">
      <h3>Unlocked Users</h3>
      <div id="unlocked_box">
        <%= render :partial => 'unlocked_users', :object => @unlocked_users %>

    <div id="cnt-locked" class="dropbox">
      <h3>Locked Users</h3>
      <div id="locked_box">
        <%= render :partial => 'locked_users', :object => @locked_users %>
    <br clear="all" />



the partial unlocked_users either displays a place holder element if there are no users, or calls the render of unlocked_user for each user. It also uses the AJAX function sortable_element which dictates what div container holds the sortable drag and drop elements, and what actions to take when an event is fired with them. This is how we trigger the call to the set_unlocked or set_locked action of the list controller for updating the individual "boxes" of users.

<% if unlocked_users.empty? %>
  <div class="target">  You have no Unlocked SAP Users.... </div>
<% else %>
  <%= render :partial => 'unlocked_user', :collection => unlocked_users %>
<% end %>

<%= sortable_element "unlocked_box",
  :update => "unlocked_box",
  :url => {:action=>'set_unlocked'},
  :tag => 'div', :handle => 'handle', :containment => ['unlocked_box','locked_box'] %>

<%= sortable_element "locked_box",
  :update => "locked_box",
  :url=> {:action=>'set_locked'},
  :tag => 'div', :handle => 'handle', :containment => ['locked_box','unlocked_box'] %>


the partial unlocked_user renders a dragble_element for each SapUser.

<div id="unlockeduser_<%= unlocked_user.userid %>" class="dragitem">
  <h4 class="handle"><%= unlocked_user.userid %></h4>
  <p><%= unlocked_user.last + ", " + unlocked_user.first %></p>
<%= draggable_element "unlockeduser_#{unlocked_user.userid}" %>


the same as for the partial unlocked_users

<% if locked_users.empty? %>
  <div class="target">  You have no Locked Users ...  </div>
<% else %>
 <%= render :partial => 'locked_user', :collection => locked_users %>
<% end %>

<%= sortable_element "unlocked_box",
  :update => "unlocked_box",
  :url => {:action=>'set_unlocked'},
  :tag => 'div', :handle => 'handle', :containment => ['unlocked_box','locked_box'] %>

<%= sortable_element "locked_box",
  :update => "locked_box",
  :url=> {:action=>'set_locked'}, 
  :tag => 'div', :handle => 'handle', :containment => ['locked_box','unlocked_box'] %>


the same as for the partial unlocked_user

<div id="lockeduser_<%= locked_user.userid %>" class="dragitem">
  <h4 class="handle"><%= locked_user.userid %></h4>
  <p><%= locked_user.last + ", " + locked_user.first %></p>
<%= draggable_element "lockeduser_#{locked_user.userid}" %>

In config/routes.rb add:

 map.connect '', :controller => "lock", :action => 'list'
and make sure that you delete public/index.html

This makes sure that any requests to the root of the server eg. http://localhost:3000, are forwarded onto the list action of the lock controller.

firing Up

Start the Rails WEBrick server by running the script:

ruby scripts/server
Open your broswer and point to http://localhost:3000.

When you connect to http://localhost:3000 (there will be an inital delay as sap4rails caches the RFC calls), you should get a screen that looks like this

A Flash movie of this in action can be seen here.

Posted by PiersHarding at 11:08 AM

September 22, 2006

saprfc and RadRails

Ruby On Rails and SAP

Last August, I wrote a weblog about SAP on Rails. In a follow up to that I'd like to explain how to import the example into an Eclipse environment called RadRails. RadRails is a specialised Eclipse install that contains a set of plugins for developing native Ruby, and Ruby on Rails applications.

The point of this blog entry is to explain how to import that example into RadRails, thus enabling all the IDE lovers out there to explore the example in their favourite environment.

All kidding aside - RadRails is a nice way to break into Rails development as it aids in visualising how a Rails application holds together.

Getting the necessary packages

The instructions for installation vary according to your OS. I will explain for both Linux, and win32.

The basic breakdown is as follows:

Install the RFCSDK

Ensure that you have the RFCSDK installed on your platform available from http://service.sap.com/connectors. For Linux this must be in /usr/sap/rfcsdk - check that librfccm.so is available in /usr/sap/rfcsdk/lib, and that it can be found at run time (you may have to add /usr/sap/rfcsdk/lib into /etc/ld.so.conf, and run ldconfig to do it).

For win32 (I've tested this on XP SP2) - make sure that the RFCSDK has been installed correctly, most likely as part of the SAP GUI client install, if you can't get it from http://service.sap.com/connectors.

Install Ruby, RubyGems, and Ruby on Rails

Detailed instructions for installing Ruby On Rails are found on the rails Website. The following is the guide for the impatient:

Install RadRails

Make sure you have a working JRE - you can get one from here - I used version 5 update 06.

Obtain and install RadRails - 0.6.2 can be downloaded from here. This is availble as a standalone IDE, and as a Plugin - what I show here is only dealing with the standalone version.

Importing the Exrates example

You should now have a workspace that looks like this:

Installing SAP::Rfc for Ruby

This part is dependent on you successfully installing the RFCSDK above.

If you are running win32 then download the saprfc 0.16 gem and install from the command line with: "gem install saprfc-0.16-mswin32.gem". Because this is a gem based install, the way that this is loaded into an application for use is different. Because of this you will need to modify SAP4Rails.rb. Navigate to this file in RadRails Exrates/lib/SAP4Rails.rb. change line 3 from: require 'SAP/Rfc'


require 'rubygems'
require_gem 'saprfc'

Under Linux, get the SAP::Rfc software, unpack and follow the build instructions in the README file, which are basically:

ruby extconf.rb
make install

Running the Exrates example

You should now see a running server:

Trouble Shooting

If the WEBrick server does not appear to start correctly, then check the console, and the rails/Exrates/server.log, and development.log. Most times the problems are going to be with the ruby, and rails install.

As this example was developed under Linux, I have noticed that the ExratesServer defined in the bottom panel Servers tab of RadRails, needs to be recreated under windows. To do this, highlight the entry, and delete (Red X for "Remove" at top of panel). Then go File => New => Server => WEBRick Server. This should give you a dialog box with Project, Name, and Port - accept the defaults, and try starting the server again.

If there is a problem with the RFC connection, then this will appear on the console log, and further debug information should be available in the rails/Exrates/dev_rfc file.

Wrapping it up

Hopefully, you now have everything up and running - Now all I need to do is to get Craig to add this one into the "Box" :-)


Posted by PiersHarding at 11:06 AM

September 1, 2006

sap4rails now has SAP::WAS - SAP Web Services Integraton

Following on from creating SAP::WAS for Ruby (SAP Web Services integration), sap4rails, has been enhanced to take advantage of SAP::WAS as an alternate "driver" for SAP connectivity. The latest version (0.04) can be obtained here, and an article showing an example of usage is here on SDN.

Posted by PiersHarding at 11:41 AM

New module SAP::WAS - SAP Web Services for Ruby

Announcing my new Project SAP::WAS for Ruby. This library enables SAP Web Services access encapsulated in the same manner as SAP::Rfc - abstracting away the complexities of dealing with SOAP packet encapsulation, and bringing the benefits of interface discovery.

The library can be found by following the directions here.

Posted by PiersHarding at 11:35 AM