CASL Tutorial
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Version 3.2 beta4 A note about the beta version. This is a work in progress, but at the same time even as a partial work, it may provide a good amount of help to new developers looking to get started with CASL. The beta number and date will be an indication of version. Text that's meant more as notes to the author is dark yellow. Text considered of good enough quality for this beta is in black. Any comments or suggestions can be sent to marketing@caslsoft.com. IntroductionCASL will allow you to easily turn your ideas into PDA applications. This tutorial will aid you in coming up to speed with the CASL tool. CASL (Compact Application Solution Language) is a Windows based RAD (rapid application development) tool that enables developers familiar with Visual Basic, Java Script, or Pascal to easily develop professional PDA (personal data appliance) apps. The CASLide (integrated development environment) can take the exact same CASL code and target the Palm OS or Win32 platform. A PocketPC target is planned. The CASL compiler comes in 2 versions: The basic version takes the CASL scripting language and outputs a pseudo code that is interpreted by a CASL runtime program designed for the targeted platform. The professional version takes the CASL language and outputs C code. Using the open source PRC Tools and GNU C Compiler (GCC), the CASLide turns the C code into a native Palm OS executable. The CASLpro compiler works for the Palm OS target only. Like desktop PC's, handheld devices with the Palm OS or PocketPC OS have a GUI (graphical user interface). The user interacts with a program by entering text, or tapping objects on the screen. The screen can include bitmap pictures to present the user with a friendly and eye-catching interface. Programs have an icon picture file. Newer PDA's have color screens. The CASL language allows you to create programs that take advantage of the GUI interface found on today's PDA's. You define your program's screen objects and associate CASL code to execute when the user interacts with these objects. It's for this reason the CASL language is described as object oriented and event driven. You take the variables, objects, and functions provided by the CASL language and create powerful and flexible programs. CASLideThe CASLide is the overall tool that allows you to work with the components of a CASL program, and compile these components into a program for the selected platform. With the CASLide you can perform the following tasks:
In the next 2 chapters we'll get you familiar with the CASLide so that you can easily work with, and install a program onto the PDA platform. Programming TechniquesIn the subsequent chapters we'll look at how the CASL language can be used to perform many of the common tasks associated with today's PDA applications. Conduits and Desktop CompanionsPDA's have a means to synchronize their data with that on a user's desktop PC. Using Palm OS terminology, this is done during a Hotsync operation. The Hotsync manager is a PC based program that supervising the Hotsync operation by calling all PDA application conduits registered with the Hotsync manager program. The basic Palm OS organizer applications (i.e. Datebook, AddressBook, etc) have a desktop version for running on a PC. The Palm OS and PC versions of the basic organizer applications share common databases, kept synchronized by Hotsync operations. It is therefore common for PDA applications to also have a desktop version of the program for viewing and editing data on the user's PC. The conduit provides a means for the PDA application and the desktop companion to share a synchronized database. CASL comes with a conduit that can be configured to synchronize 1-way or 2-way with PC-based data. The database can be in a native CASL format, or a format supported by the ODBC object. The CASL conduit only runs on the Windows platform. Because CASL supports the Windows platform as a target, this is the easiest way to provide a desktop version of a CASL PDA application. The same code can be compiled for both platforms. The CASL language provides a native means to access CASL formatted databases. An alternative is to create the desktop version with other available 3rd party RAD tools for Windows, such as Visual Basic, or Delphi. These tools provide a native means to access ODBC formatted databases. We have a chapter that looks at this in more detail as well. DistributionFinally once your application is ready for your users, how do you get it into their hands? We have a chapter that looks at how to write an installation program. We'll briefly mention some good internet archive sites which allow internet distribution of your new application, and a means to have credit card transactions processed, even it you don't have a website. AppendixesReference information is provided in Appendixes. Other ResourcesCASLide Manual CASL Language Manual |
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