Team Development with VB 4.0 Enterprise Edition

Team software development adds a new layer of complexity to the alreadychallenging world of programming. When multiple developers work on a singleproject, the danger of one programmer overwriting another programmer's changesis always present. Programmers who are aware of this possibility guard againstit by keeping a private copy of each source module they work on. This way, iftheir changes get stepped on, they can go back to their private copy to cut andpaste their work back into the module.

At first, this solution seems reasonable, but this cure can be more deadlythan the disease. Code that's added back into a project later canunintentionally affect other pieces of code that other developers addindependently. Further, this re-addition can disrupt the software testingprocess. In the best scenario, the same code is tested multiple times, slowingthe development process. In a worse scenario, someone adds the code after thecomponent testing phase, and the added code is never tested. You can imagine howthis situation can introduce serious defects. In addition to the multipledeveloper problem, team application development faces other problems such asversion tracking, isolating code differences, and regenerating historicalreleases.

In the Enterprise Edition of VB 4.0, Microsoft addresses such teamdevelopment problems by bundling in Visual SourceSafe (VSS)--a version-controlapplication. VSS introduces a much-needed system of checks and balances to theteam software development effort and provides tight integration with VB'sdevelopment environment. Also, you can use VSS for version management of both16-bit and 32-bit applications. Basic version-control capabilities includesource check-in and check-out and advanced features such as visual filedifferencing, file modification history, and tracking the relationship betweenproject files.

VSS comes in two parts: a server component and a client component.Developers usually install the server component in a shared LAN directory somultiple developers can access it. The server component is the centralrepository for the shared development projects. The client component provides alink between the client development environment and the server portion of VSS.For VB and Visual C++, the client portion integrates directly into theInteractive Development Environment of each product.

Team Development
Before you can use VSS, you must first set up its administration. VSS comespreconfigured with two user accounts: Guest and Admin. As you might expect, theAdmin account lets you perform the administrative functions for VSS, and theGuest account is a sample user account. As shipped, the product has a blankpassword for both profiles.

To set up a new VSS account, run the Visual SourceSafe Administrationprogram that was installed into the Visual SourceSafe program group and sign inusing the Admin account. Then take the menu option to add a new user. Enter theuser identifications and passwords for all the developers who will use VSS. Thislogin is just for VSS, and it's separate from NT's domain login or SQL Server'sdatabase login. You can also configure VSS to use the network user name andpassword, which will bypass VSS's usual login dialog.

After you enter the user accounts, you can have the users run the ClientSetup program on their local systems. You can run the Client Setup before addingthe user accounts, but if you do, the users won't be able to log in to VSS. TheVSS client installation process adds several options to the VB 4.0 Toolsmenu, as shown in screen A.

Using VSS
After you install the client portion of VSS, every time you save a projectthat's not under source control, a dialog appears that asks whether you want toadd the project to SourceSafe. To add the project to VSS, you select the VB 4.0Add-Ins menu shown in screen B.

From the Add-Ins menu, you select the Add Pro-ject to Source Safeoption to add all the project's files to VSS. Additionally, the Open NewSource Safe Project option lets you start a new project from scratch. TheRun SourceSafe option opens up the SourceSafe Explorer, which lets youwork with existing SourceSafe projects. The Options menu lets youcustomize the operation of VSS.

Selecting the Add Project to SourceSafe option displays a dialogthat lets you assign a meaningful name to your project and use the associatedlist box to define the project's scope. The list box displays all the VSSprojects that are already created. You can save your project at the root level,or if yours is subordinate to another project, you can save yours as asub-project.

After assigning the project name and scope, click on the OK button toproceed to the next dialog. It shows all the files in the VB project. Each filethat has an x in the check box will be added to the VSS project. You canalso write a comment that helps identify this project to other users of VSS.Pressing the OK button copies all these files into VSS. Note that in VSS,multiple projects can share files.

The next time you work with this project in VB, you must use the Check-Outand Check-In options on VB's Tools menu. VB projects that areusing VSS will have a small red lock displayed next to each module in VB'sproject window. An important thing to remember when you're using VSS is that younever work directly with the files that are archived: You must check out thefiles to modify them and check them back in when you are finished.

One closing tip: Try to avoid checking in files that are half finished.Although this practice is not always possible when you first start a project,you still aim to keep files checked out at least until they compile andpreferably until after they are component-tested. If you follow this simpleprocedure, you'll know that your developers can always build an executable filefrom the files VSS stores.