Establishing the Developement Environment

Establish the environment for source-code version control - Chapter Objectives

1. The first objective requires you to have some knowledge of Visual SourceSafe 6.0, which is bundled with VB 6.0, Enterprise Edition. You can use Visual SourceSafe to manage the files for source code through different versions of a single project.
   
   You can also use Visual SourceSafe to prevent conflicts and confusion among developers who are working on the same project at the same time.
2. Install and configure Visual Basic for developing desktop/distributed applications

Contents

1. Implementing Source-Code Control with Visual SourceSafe
2. The Nature of a Visual SourceSafe Project
3. The Visual SourceSafe Database
4. Visual SourceSafe Administrator
5. Archiving and restoring Visual SourceSafe databases
6. Restoring a Visual SourceSafe Project from Archive
7. Using Visual SourceSafe Administrator to Set Up and Maintain Users
8. Visual SourceSafe Explorer
9. Creating a New Project Folder in Visual SourceSafe
10. Adding Files to a Visual SourceSafe Project
11. Setting the Working Folder for a Project
12. Checking Out, Checking In, and Getting Working Copy
13. Source-Code Labeling and Version Numbers
14. Source-Code Sharing
15. Source-Code Branching
16. Pinning an Earlier Version of a File for Use in the Current Version of a Project
17. Merging Two Different Versions of a File

Implementing Source-Code Control with Visual SourceSafe

Version control is a term that describes the actions that software developers must take to keep track of the physical files that go into various versions of a software product. Version control is basically concerned with two types of control:

• Keeping track of changes to files over time and matching the various versions of a file with versions of a software product.
• Managing concurrent changes made by multiple developers to a project's files and keeping their changes from conflicting with each other.

Visual SourceSafe has three basic components that you need to know about to understand how it works to implement version control:

• The Visual SourceSafe database. This is the repository for the various versions of source code and other files that Visual SourceSafe administers. The Visual SourceSafe database stores the files in a compressed, proprietary format. It must be visible to all developers and administrators who need to use Visual SourceSafe.

• Visual SourceSafe Administrator. This application enables one or more administrators to manage the Visual SourceSafe database, to manage users of Visual SourceSafe, and to define the users' rights in general and also for particular projects.

• Visual SourceSafe Explorer. This application resides on each developer's workstation. It is the main vehicle that developers use to manage the source code stored in the Visual SourceSafe database.

Visual SourceSafe is typically installed as an option with VB or Visual Studio. You should make sure that the Visual SourceSafe database is installed in a location visible to all who will need to use it (probably on a network drive). The default name for the installed folder is VSS. The exact location of this folder will depend on the choices you make during Visual SourceSafe installation.

The Nature of a Visual SourceSafe Project

A Visual SourceSafe project typically corresponds to the physical files in a development project. Developers usually think of a Visual SourceSafe project as containing source-code files (in the case of a VB project, file types would include VBP, FRM, BAS, CTL, and so forth).

A Visual SourceSafe project can contain any files important to the project, however—such as email documents containing correspondence, design, specification, and project-management files in word processor format or in the formats of other software tools, as well as the latest compiled version of the executable files created from the source code.

The Visual SourceSafe Database

The Visual SourceSafe database contains all the files that Visual SourceSafe maintains. Visual SourceSafe stores the files in a proprietary, compressed format.

You will find the Visual SourceSafe database under the main Visual SourceSafe directory (usually named VSS) in a folder named Database.

You will see several files under this folder and a lot of other folders containing many other files. You should never try to manipulate the contents of the Visual SourceSafe database manually, because Visual SourceSafe has its own internal scheme for managing the database.

It is possible to have multiple Visual SourceSafe databases set up in the same environment. When administrators or developers open the Visual SourceSafe Administrator or the Visual SourceSafe Explorer (as mentioned in the following sections), they have a choice of Visual SourceSafe databases.

Figure in the section titled "Using Visual SourceSafe Explorer" illustrates the choice of databases for a user in Visual SourceSafe Explorer. A Visual SourceSafe administrator can also archive and restore Visual SourceSafe databases, as discussed further in the section titled "Archiving and Restoring Visual SourceSafe Databases."

Visual SourceSafe Administrator

You can use Visual SourceSafe Administrator to

• Set up and remove users of Visual SourceSafe and set their Visual SourceSafe passwords.

• Assign rights to users of Visual SourceSafe for specific projects or in general.

• Set options for Visual SourceSafe projects.

• Archive and restore Visual SourceSafe projects in specific Visual SourceSafe databases.

• Set options for the general behavior of Visual SourceSafe.

To answer SourceSafe-related questions in Visual Basic, you will need to know about some of these administrative functions:

• Archiving and restoring VSS databases

• Setting up VSS users

Restoring a Visual SourceSafe Project from Archive

STEP BY STEP

1.     Choose the Archive, Restore Projects menu option.

2.    On Screen 1 of the Restore wizard, browse to the Visual SourceSafe archive (SSA) file that you want to restore, and click the Next button (see Figure 2.5).


FIGURE 2.5 - Specifying an existing Archive file to restore from.

3.    On the screen for step 2, choose the projects from the archive that you want to restore (see Figure 2.6)


FIGURE 2.6. - Specifying the projects that you want to restore.

4.    On the screen for step 3, select where you would like the project restored. Click the Finish button and wait for the Restore wizard's notification of success (see Figure 2.7).


FIGURE 2.7. Step 3 of the Restore wizard.

You can use the Archive/Restore feature of Visual SourceSafe to transfer projects between two Visual SourceSafe databases. To transfer a project from one Visual SourceSafe database to another, follow these steps:

1.     Archive the project from the database where it originally existed (the source).

2.    Restore the archived project to the destination database.

Using Visual SourceSafe Administrator to Set Up and Maintain Users

Although Visual SourceSafe Administrator can leave most general Visual SourceSafe settings at the installed default values, there is one task that you must perform in Visual SourceSafe Administrator for Visual SourceSafe to function properly: setting up users.

Developers cannot have access to Visual SourceSafe Explorer and the projects contained in the Visual SourceSafe database unless they have a logon account for the Visual SourceSafe database. To set up a user for access to the Visual SourceSafe database, follow these steps:

STEP BY STEP
2.3 Setting Up a User with Visual SourceSafeAdministrator

1.     Open Visual SourceSafe Administrator and choose Users, Add User from the main menu to bring up the Add User dialog box (see Figure 2.8).


FIGURE 2.8 - Adding a SourceSafe user account.

2.    Fill in the logon ID for the user whom you are setting up.

3.    Assign a password.

4.    If you don't want the user to be able to change information stored in the Visual SourceSafe database, check the Read Only box as well.

5.    Click OK to close the dialog box and create the user account.

NOTE: Visual SourceSafe Security and Windows Security Visual SourceSafe Explorer will automatically try to use the Windows user ID and password to log on a user who runs Visual SourceSafe Explorer. If the user ID and password match a user ID and password in Visual SourceSafe, the user will receive no logon prompt to Visual SourceSafe Explorer.

Visual SourceSafe Explorer

When you run Visual SourceSafe Explorer, the first thing that you see depends on how the administrator set up your Visual SourceSafe account:

• If the Visual SourceSafe administrator set up a user with the same name and password as your Windows logon and password, Visual SourceSafe Explorer will proceed immediately to the main screen.

• Otherwise, Visual SourceSafe Explorer will present you with the logon screen. In this case, you will need to supply a valid Visual SourceSafe logon/password combination as set up by the Visual SourceSafe administrator.

You can also click the Browse button on the logon screen to choose from all the Visual SourceSafe databases recognized by Visual SourceSafe on your system (see Figure 2.10). You can also wait until you see the main Visual SourceSafe screen, and select the File, Open SourceSafe Database from the menu to choose a different database.

FIGURE 2.10 - Choosing a Visual SourceSafe database.

Following is a list of some of the things that you can do with a project's files in Visual SourceSafe Explorer:

• Set working folder. You can specify the physical location on your system where you want to put a project's files when you view them or work with them.
• Check out. You can get a writable copy of a file from the SourceSafe database. Normally, only one developer at a time can check out a given file.
• Check in. You can return a modified copy of a file to the SourceSafe database. The modified file is now available for other developers to check out.
• Get working copy. You can get a read-only copy of a file from the Visual SourceSafe database. Anyone can get working copies of a file, even if someone else currently has it checked out.
• Label. You can designate versions of one or more files in a project with a label of your choosing. You can get copies of all the files designated with a single label and thus reproduce a particular version of a project.
• Share. You can share the same copy of one or more files between various projects.
• Branch. You can break the link between shared copies of the same file so that you can then develop the copies independently.
• Pin. You can freeze a particular version of a file or project so that no more changes can be made to it.
• Difference. You can view the differences between two different versions of a file.
• Merge. You can merge two different versions of a file together. You can view each difference and decide how to merge.

The following sections discuss many of these activities.

• Creating a New Project Folder in Visual SourceSafe
• Adding Files to a Visual SourceSafe Project
• Setting the Working Folder for a Project
• Checking Out, Checking In, and Getting Working Copy
• Source-Code Labeling and Version Numbers
• Source-Code Sharing
• Source-Code Branching
• Pinning an Earlier Version of a File for Use in the Current Version of a Project
• Merging Two Different Versions of a File

Creating a New Project Folder in Visual SourceSafe

The structure for storing Visual SourceSafe projects looks somewhat like the Windows File Folder tree as presented by Windows Explorer (see Figure 2.11).

FIGURE 2.11 - The project tree in Visual SourceSafe Explorer.

All projects in the Visual SourceSafe database are stored under a root folder (denoted by a folder labeled "$/" at the top of the tree hierarchy).

To add a new project to Visual SourceSafe, follow these steps:

STEP BY STEP
2.4 Adding a New Project to Visual SourceSafe

1. Run and log on to Visual SourceSafe Explorer.
2. Select either the root folder ($/) or an existing project folder. The project you create will belong under the folder that you select.
3. Choose File, Create Project from the menu.
4. Under the Create Project dialog box, assign a name to the project and enter any comments. Click the OK button to create the new project's folder in Visual SourceSafe (see Figure 2.12).
   
   
   FIGURE 2.12 - Creating a new project folder (figure shows both the dialog box to create the folder and the newly created folder).
5. Add files to the project (you may do this at a later time). The next section describes this action in detail.

• Creating a New Project Folder in Visual SourceSafe
• Adding Files to a Visual SourceSafe Project
• Setting the Working Folder for a Project
• Checking Out, Checking In, and Getting Working Copy
• Source-Code Labeling and Version Numbers
• Source-Code Sharing
• Source-Code Branching
• Pinning an Earlier Version of a File for Use in the Current Version of a Project
• Merging Two Different Versions of a File