Before you learn how to change ProMatrix Setup, you should understand how VPM Enterprise creates, names and references the files it puts into new projects. The important points you should know include:
· Most of the files that VPM Enterprise puts into a new project are copies of the files in the New Project directory of VPM Enterprise.
· Many of the files that VPM Enterprise puts into a new project are given a name that uniquely identifies the application to which the file belongs.
· VPM Enterprise applications use properties to call programs and forms. Using properties to contain the names of the programs and forms to be called allows the following:
· VPM Enterprise application programs and forms can have application-specific file names or, for that matter, any file name.
· You can replace a VPM Enterprise provided application program or form with your own program or form with a different name without needing to recode the calls to the program or form.
· If you have files (for example, programs) that you would like VPM Enterprise to put into every new project, you can set up VPM Enterprise to handle your files just like it handles the VPM Enterprise files that go into new projects.
The New Project Objects section later in this chapter describes how you can replace VPM Enterprise programs and forms with your own and how you can set up VPM Enterprise to put your files into every new project.
Why Application-Specific File Names?
Application-specific file names prevent the following kinds of problems:
· Some application development systems use the same file names for different projects. That approach is an invitation to disaster. For example, if you modify a form file named “SEARCH” for one project, but have another project on the same computer with an unmodified “SEARCH” file, there’s just too much potential for confusion and inadvertent swapping of the files. Generally, you should avoid having files with the same name but different contents on the same computer.
· Some application development systems store common files used by different projects in one central location. That approach can cause you to lose control of the version of a file included in a project. For example, if the application development system is upgraded, the applications you built before the upgrade may be forced to use the upgraded versions of common files when you next rebuild the application. You may actually want or need to use the pre-upgrade versions, but may only be able to do so with great difficulty.
VPM Enterprise’s use of unique file names for each project means that:
· You can easily identify the files belonging to each project you create. If you modify a file for one project, you can’t inadvertently swap it with the equivalent file in another project.
· When VPM Enterprise is upgraded with new features, you can choose whether to include the new features in already existing applications. If you want to include a new version of a file in an existing application, you can simply copy the file from the New Project directory of VPM Enterprise to the application directory and rename it.
How New Project Files are Named
VPM Enterprise files with names that begin with “SAPP” and “SSYS” are renamed when copied to a new project. The name identifies the file’s source and its owner.
· File Source
· The name of the file begins with “S”, identifying it as a system file. Consider beginning the names of your files that you want VPM Enterprise to put into new projects with a “D” (for “developer”). If you make the first character of your file names a “D”, you can easily distinguish them from the VPM Enterprise provided files, and when VPM Enterprise copies them into new projects, it will give them application-specific names as described further below.
· File Owner
· VPM Enterprise inserts the application prefix you select when you create a new project into positions two through four of the names of the files it puts into the new project. Accordingly, a file’s name identifies the application to which it belongs, and every application’s files are unique.
When VPM Enterprise copies a file into a new project, it replaces positions two through four of the file name with the application prefix only if the name of the file being copied begins with “SAPP”, “SSYS” or “DUSR”.
Tip: Start the names of your files that you want VPM Enterprise to copy into new projects with “DUSR” so that VPM Enterprise will make their names application specific. The Naming Conventions chapter suggests a file naming convention that you might want to adopt for the last four characters of file names. The New Project Objects section later in this chapter explains how to tell VPM Enterprise which files you want included in new projects and where to store them.