programacion vfp

1. Web-Services
in Visual FoxPro 9.0
FoxPro User Group of German language
Rainer Becker
Presentation at SDN 15 Sep 2006
WEB

2. Working with WebServices
 Friday, 15.09.2006, 13:00 – 14:15
 Visual FoxPro is most often used for rapid application
development of Desktop-applications but also for
Client/Server applications, both sometimes running on
Terminal Services for ease of deployment.
 But you can also create WebServices with this powerfull
development environment without any problems!
 The fast database and string functions allow the creation of
fast services for distributed applications.

3. Rainer Becker
 dFPUG
 Online offers
 Loose Leaf Magazine
 VFP-DevCon
 VFP-Lokal/Develop
 Framework Visual Extend
 MVP, MCP, ISV
 Wizards & Builders GmbH

4. Where do I get VFP ?
 Update from 6.0, 7.0, 8.0 or VS 97
 Not for VFP 5.0 or older
 International or US/Canada-Version
 different pricing
 technical identical
 no problem in The Netherlands
 dFPUG offers localization
 we could create a Dutch version if someone is interested…

5. Topics
 Existing WebServices
 Calling WebServices
 Definitions and versions
 Preparation
 SOAP-Toolkit
 IIS-Configuration
 Additional hints
 Other ways to skin a cat

6. Remarks
 You always need a COM-Server!
 Creating COM-Servers is a different session…
 Please create a COM-Server first and test it…
 and maybe have a look at existing WebServices…
 The calling logic in the Internet is different in general.
Therefore business objects are not really usable if they are not
designed for one-time-calls. Separate COM-Servers are often
easier to use!
 WebServices have to be strongly typed which is only optional
for COM-Server, maybe create a separate PRG with
 For deployment you always need a Windows Webserver in the
Internet…

7. Existing WebServices
 Instead creating a WebService directly you should
first have a look at existing WebServices, e.g.:
 FoxWiki (http://fox.wikis.com)
 Universal Thread (http://www.universalthread.com)
 ProFox (http://www.leafe.com)
 FoxCentral (http://www.foxcentral.com)
 Google, Amazon, eBay, FedEx, WhoIs, CurrencyConverter,
BabelFish, Headline News
 dFPUG-Portal (see http://apf.dfpug.de)
 dFPUG-Forum (see Visual Extend example)

8. And Again: The TaskPane!

9. Client for WebServices
 Interactive Testing with the Taskpane
 Integration into your own forms:
 Open the Form
 Open the Toolbox
 Drag & Drop the class WebService onto the form
 Select the object with the mouse
 Right mouseclick for Builders
 Call the XML WebService Builders

10. WebService-class in your form

11.  Enter parameters
 View results as XML
 View results in Grid
Testing:

12. Match parameters and output

13. Use complex data

14. Thats it for calling a WebService
 Since Visual FoxPro 8.0 there are powerfull tools that
support developers in calling WebServices…
 Before creating your first own WebSerivce have a
look…
 This could easily fill a another complete session…
 There are multiple articles available as well as the
updatebook for Visual FoxPro 8.0!

15. Definitions
 WSDL: Web Service Description Language
 XML-description similar to a COM-server definition
 WSML: Web Service Meta Language
 COM-Reference, see Program FilesMSSOAPSOAP.CHM
 UDDI: Universal Description, Discovery, Integration
 List of available WebServices, seldomly really used
 SOAP: Simple Object Access Protocoll
 SOA: Service Oriented Architecture

16. Version History
 Introduction of WebServices in:
Visual FoxPro 7.0 with SOAP-Toolkit 2.0
 Current: Visual FoxPro 9.0 mit SOAP-Toolkit 3.0
 Lifecycle-Support
 Visual FoxPro 9.0 till 2014
 SOAP-Toolkit till 2013 (for VFP ONLY!)
 In the future: WebServices via INDIGO
 With WinFX as AddOn for XP as well as in Vista
 encapsulates VFP-WebServices completly in .NET
 this even includes runtime file inclusion/distribution/registration

17. Usefull WebServices in Apps
 Examples from the Framework Visual Extend 9.5:
 Posting of messages in Support-Forum
 Sending of error messages to error database
 Registration of users for trial version
 Orders of users (update from trial to full version)
 Download of Updates
 If Internet or WebServices (Firewalls!!!) not available
eMail is used instead…
 No WebService needed for VFX-Taskpane…
 Active FoxPro Pages used instead, see http://afp.dfpug.de

18. Prepare a COM-Server
 Creation option:
Multi-Threaded
COM-Server
 Minimum
1x OLEPUBLIC
 1 WebService per
OLEPUBLIC
 Max. 1 Webservice

19. WebService Creation
 Projektinfo Servers:
 Multi-Use
 Project Name
 Multi-Threaded and
Multi Use: needed
for Internet due to
RAM constraints!

20. WebService Publishing Wizard
 Call the WebService-
Builders in project 
 Check the path
 Opt. Select a class
 Opt. additional options

21. Extended Options
 Optionally use
extended options:
Switch to ASP
 ProjectHook
 Wsphook in
_webservices
 Save in table
FOXWS.DBF in
_FOXCODE
 Create IntelliSense-
Script

22. Virtual directory in IIS
 Created auto-
matically for you
 Differences
between Path,
virtual directory
and startup
directory!
 Ask you
administrator <g>.

23. Builder Results
 .WSDL
(Description)
 .WSML
(Meta/COM)
 Opt. additional
ASP-page
 will be called
directly
 ProjectHook for re-
generation each
time you change

24. Register at IntelliSense
 Register the class under Types / Web Services in the
IntelliSense- Manager

25. Call the WebServices
 IntelliSense creates the needed Code for you:
 and shows all methods that can be called…

26. What can go wrong?
 Potential problems (OLE-error messages):
 with paths:
Windows/System32
(Runtime)
 CD JUSTPATH(
_VFP.ServerName)
 Problemes with SOAPISAP.DLL (install or use ASP)

27. Registration of Listener (1)
 Registration of
SOAPISAP.DLL for
performant ISAPI-
Listeners:
1. Default-Website,
Properties, Home
Directory
2. Button Configuration
3. Select the extension
.WSDL

28. Registration of Listener (2)
 Select C:Program FilesCommon
FilesMSSoapBinariessoapisap.dll
 If not visible:
Select e.g. INI
and change it
 NOT on WinXP…

29. Alternate Call: SOAP-Client
 Instead of using the classes of Visual FoxPro you can
also directly access WebServices via SOAP-Client:
 Code example:
lows = NEWOBJECT("MSSOAP.SoapClient30")
lows.MSSoapInit(
"http://dlab.homeip.net/webservices/dlab.wsdl")
? lows.timechecker()
 Much easier way to call but you have to do it yourself

30. Integrating minimum security
 Internet Information Services
 Properties of virtual directory
 Page Directory Security
 Disable anonymous access
 Enable standard authentication
 Or extend the above code example:
lows.ConnectorProperty("AuthUser") = "username"
lows.ConnectorProperty("AuthPassword")= "password"

31. Type declaration important!
 Strong typing required for parameters/return value
 can only be done programmatically, see COM
 FUNCTION getnews (ldDate as Date) as String
 Re-Publish via Wizard necessary so that
<message name='hwpclass.getnews'>
</message>
 is changed to the correct new definition for you:
<message name='hwpclass.getnews'>
<part name='ldDate' type='xsd:dateTime'/>
</message>

32. Call COM-Server indirectly
 Create a programm to call the COM-Server
DEFINE CLASS MyCOMInterface AS Custom OLEPUBLIC
FUNCTION MyMethod (MyParm AS String) AS String
LOCAL o AS myclass
o = CREATEOBJECT("myclass")
RETURN o.MyMethod(MyParm)
ENDDEFINE
 Now you can change the COM-Server as often as you like
without having to republish it (if interface remains the same)

33. Creation: Release the DLL
 Computer Mgmt:
Restart IIS
 or: IISRESET at the
DOS-Prompt
 or: KILL.EXE to
remove DLL from
memory without
questions asked

34. In a lot of case you can have
an easier start
Multiple examples available at
http://afp.dfpug.de

35. Creation of AFP-Pages
 Using Visual FoxPro as a script language in HTML-
Pages with Active FoxPro Pages (AFP/AFX):
<% FoxPro-Code %>
 See examples at http://afp.dfpug.de
 Create pre-formatted HTML-tables with parameters
 Return RSS
 Return XML
 See usage examples at http://portal.dfpug.de

36. Web applications:
VFX–AFX Wizard
 Internet-forms via mouse click!
Prerequisites:
 VFX 9.5 and VFP 9.0 SP1
 AFX
 like ASP, but based on VFP
 IIS
 FoxPro-version under creation for AFX
Scalability:
 via AFP for multipel parallel users / AFX for 10 users

37. Articles
 02-16 Creation of WebServices in Visual FoxPro
 06-15 Program your Data
 06-32 Searching with WebServices
 06-35 Publish your first WebService 1
 06-36 Publish your first WebService 2
 06-37 Publish your first WebService 3
 07-16 Search with VFP in Google
 01-03 Working with WebServices in VFP7 (New18)
 Extensions of COM and WebServices in VFP 8.0
 Whats New in Visual FoxPro 7.0 Chapter 15

38. Additional material
 Visual FoxPro 9.0
 Update book
 Visual FoxPro 8.0
 Update book
 Articles
 FoxTalk
 FoxPro Advisor
 FoxX Professional (German)

39. Thank you very much!
Send questions hotline@dfpug.de
or (better) http://forum.dfpug.de
Visit our websites: http://www.dfpug.de, http://portal.dfpug.de,
http://forum.dfpug.de, http://newsletter.dfpug.de,
http://devcon.dfpug.de, http://roadshow.dfpug.de,
http://www.visualextend.de, http://www.linuxtransfer.de,
http://www.visualfoxpro.de

40. Riddle of the day
? CHRTRAN(CHRTRAN('S6O1 W2S634G 5789',
'6789', 'TIME()'), '12345','PAINT()')