How to create VDF Web Applications: Difference between revisions

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When you have decided to use ASP , then you should try to resist the urge to generate all the html from Visual DataFlex. There are some existing techniques in the web world that can save you time in the long run.
When you have decided to use ASP , then you should try to resist the urge to generate all the html from Visual DataFlex. There are some existing techniques in the web world that can save you time in the long run.


First of all you should understand that ASP is not a new programming language that you need to learn. VDF code can be exposed for asp via COM so that you can call the components via vbscript. ASP is about interfacing code to HTML in a easy way - so use it !
First of all you should understand that ''ASP is not a new programming language that you need to learn.'' VDF code can be exposed for asp via COM so that you can call the components via vbscript or jscript.


Ok - I lied. if you don't know vbscript you will probably spend a day or two looking at [a tutorial][http://www.w3schools.com/Vbscript/default.asp].
The overall idea is : '''do not write vdf code to generate html. use asp'''. ASP is about interfacing code to HTML in a easy way - so use it ! 
== Putting on your [http://www.professorsolomon.com/thinkingcap.html Thinking cap]==
Grab your the DDsrc from your old application and expose these using Web Objects .


== Datamodel model using VDF on the server ==
*WBO
*WBO
*Global.asa (this is where your code is stackup up. check the list of WBP's there)
*Global.asa (this is where your code is stackup up. check the list of WBP's there)


== Styling using css ==
== Styling using css ==
Cascading style sheets can be used to alter the appearance of your web page.
 
Using css for styling can help you if you don't like doing design yourself!  If you style using css then somebody else can do the design for you.
 
*[http://www.w3.org/Style/CSS/ css]
*[http://www.quirksmode.org/css/contents.html quirksmode css]
*[http://www.quirksmode.org/css/contents.html quirksmode css]


== Javascript on the client ==
== Javascript on the client ==
Now - after having being told that you really shouldn't be doing any clientside code when you are a vdf programmer, then here are some instructions for doing exactly that! (Note that you can accomplish a lot just by using the wizards in the AJAX library )
Javascript can be good for validating what the user enters on the screen. It can also be good for fancy [[AJAX]] techniques.


== Validation ==
== Validation ==
Here are some good links for validating :
*[[HTML]] ( validate here: [http://validator.w3.org/]  )
*[[HTML]] ( validate here: [http://validator.w3.org/]  )
*[[CSS|Cascading Style Sheets]] ( validate here: http://jigsaw.w3.org/css-validator/ )
*[[CSS|Cascading Style Sheets]] ( validate here: http://jigsaw.w3.org/css-validator/ )

Revision as of 21:19, 24 January 2009

How to create VDF Web Applications page under construction


Introduction

Getting started

To be able to develop ASP pages , then you need Internet Information Server. The most easy way to get that these days is to grab Microsofts Web Platform installer here :

http://www.microsoft.com/web/channel/products/WebPlatformInstaller.aspx

This tool will provide you with a full stack for developing asp related things. It will also keep track of certain things you need to enable on Windows Vista and Windows Server 2008.

You will also need to install Webapp server from the Portal:Visual DataFlex installer. Note that you will need version 14.1 to support the windows 2008 server.

The overall idea

When you have decided to use ASP , then you should try to resist the urge to generate all the html from Visual DataFlex. There are some existing techniques in the web world that can save you time in the long run.

First of all you should understand that ASP is not a new programming language that you need to learn. VDF code can be exposed for asp via COM so that you can call the components via vbscript or jscript.

Ok - I lied. if you don't know vbscript you will probably spend a day or two looking at [a tutorial][1].

The overall idea is : do not write vdf code to generate html. use asp. ASP is about interfacing code to HTML in a easy way - so use it !


Putting on your Thinking cap

Grab your the DDsrc from your old application and expose these using Web Objects .

  • WBO
  • Global.asa (this is where your code is stackup up. check the list of WBP's there)


Styling using css

Using css for styling can help you if you don't like doing design yourself! If you style using css then somebody else can do the design for you.

Javascript on the client

Javascript can be good for validating what the user enters on the screen. It can also be good for fancy AJAX techniques.

Validation

Here are some good links for validating :