INFO: Visual Modeler 1.0 Frequently Asked Questions (FAQ)Last reviewed: August 26, 1997Article ID: Q166395 |
The information in this article applies to:
SUMMARYThe following is taken from the Visual Modeler Frequently Asked Questions Help file supplied with the Visual Modeler product.
MORE INFORMATIONThe following questions are covered by this article:
Questions and Answers1. Q. What is Microsoft Visual Modeler?
A. Visual Modeler is a graphical object modeling tool that is tightly
integrated with Microsoft Visual Basic 5.0. Visual Modeler allows you to
fulfill the promise of object-oriented programming by quickly and easily
creating applications that are maintainable, have a long lifetime, and
are comprised of components that can be reused in other applications.
These are the main features of Visual Modeler:
- Class diagrams - the design of the system you are about to develop in
terms of a model using a high level of abstraction. The diagram
notation provided by Visual Modeler is a subset of the modeling
constructs defined by the Unified Modeling Language (UML).
- Code generation - the ability to generate Visual Basic code
automatically from the design model you have created with Visual
Modeler.
- Reverse engineering - the ability to create or update the
model automatically with changes made to the Visual Basic code.
- Round-trip engineering - the combination of modeling, code
generation, coding, and reverse engineering.
2. Q. What is a model in Visual Modeler?
A. A model of a system describes a view of the system on a higher level
of abstraction than the source code. Compare a system model to the
description of a society and the source code to bricks in a building
When describing a society, you do not do it in terms of bricks, you
probably do it in terms of buildings and groups of buildings with
different purposes (schools, industries, shops, houses, and so on) and
the communication paths in between (streets, roads, railways, and so
on). Such models of complex systems are needed because it is impossible,
and not interesting to everyone, to understand all the details of the
system. By modeling, you can focus on one aspect at a time and also work
on a higher level of abstraction. The more complex your system is, the
more you need a model.
In Visual Modeler, a system is modeled from three different views, each
one with its own purpose:
- Logical view - describes the logical structure of the system (the
classes and their relationships).
- Component view - describes the physical structure of the system (how
the system is divided into .exe files and DLLs).
- Deployment view - shows the system’s nodes and the connections in
between and the allocation of processes to nodes.
3. Q. How can Visual Modeler help during design?
A. There are several situations in the design phase when using a visual
modeling tool such as Microsoft Visual Modeler has major advantages.
The first situation is the early phase when you decide which classes
you need and how they are related. When the first outline of the object
model is stable, you need to specify each class. The requirements might
still change, though. Using Visual Modeler to sketch different solutions
and specifying the classes means that:
- It is easier for other people to understand the system design from
your diagram than from the code.
- Your development team has a common diagram notation, which means that
everyone understands the diagrams without further explanation.
- You can concentrate on what the system is supposed to do, and not how
things are going to be implemented.
- It is a quick job to change the diagrams and specifications when the
requirements change, compared to the time it takes to rewrite the
corresponding code.
- You can try various design approaches and communicate your ideas
among the development team members.
4. Q. How can Visual Modeler help during implementation?
A. When the interface of the classes is stable (when the public
properties, relationships, and methods are defined in Visual Modeler),
it is time to implement the model. Using the round-trip engineering
features in Visual Modeler during implementation means that:
- You do not have to write the skeleton Visual Basic source code. You
simply generate all class modules, properties, and method
specifications. Then, the implementation phase needs to be refined to
generate source code until you have an executable system.
- You can keep code and model consistent with each other automatically
by using the reverse-engineering feature.
- If you have an undocumented system, you can use the reverse-
engineering feature to create a model of that system, and continue
the development work in the new model.
- You can include ActiveX components in your model by using the
reverse-engineering feature.
5. Q. How can Visual Modeler help during further development?
A. The model is used when you discuss the structure of the system with
others or when you want new project members to understand the
system quickly, as well as during further development of the system to
get a quick overview of how things are related in the system.
A successful system always needs further development. If you have used
Visual Modeler to document your system you will notice that:
- The model documents important design decisions.
- New project members easily understand how the system is structured by
looking at the diagrams and studying the high-level specifications of
the classes.
- It is easy to introduce changes into the system because Visual
Modeler can tell you exactly which classes are affected by a change
in one class.
6. Q. How is the Logical View documented?
A. Each package, class, method, property, and relationship in the model
is completely described by a specification. The model is illustrated in
several diagrams, each with its own purpose. Thus, a class in the model
can appear in more than one diagram. In the logical view, documentation
of the following types are used to describe the system:
- Three-tiered diagrams - illustrate the overall structure of the
system. These diagrams support the three-tiered architectural
approach used when building Microsoft Visual Basic applications by
separating the components of the system into three layers of
services: User Services, Business Services, and Data Services. The
three-tiered model especially supports the creation of large, complex
client/server applications. By default, a three-tiered diagram called
Three-Tiered Service Model is created at the top level of the Logical
View when a new model is opened.
- Class diagrams - illustrate a part or an aspect of the model of
special interest. For each logical package in the model there is a
special, automatically-created class diagram called Package Overview.
A Package Overview diagram illustrates the contents of the package to
which it belongs. It is automatically updated when a new class is
assigned to or removed from the package. To create a new class
diagram, select a package, choose Class Diagram from the Browse menu,
and double-click on New. The same diagram notation is used in class
diagrams, Package Overviews, and three-tiered diagrams.
- Specifications - hold all details about the elements in the model.
Each class, method, property, or relationship in the model is defined
by a specification which is automatically created and updated. The
specification is presented in a dialog box with tabs for different
aspects. In the dialog box, you are able to define and view the
details about a class, method, property, or relationship. The easiest
way to open the specification of a class is to double-click on the
class symbol in a diagram or on its name in a list.
Installation Questions1. Q. I can't find the Class, Reverse Engineering, or Code Generation
Wizard on the Tools menu. Where is it?
A. Open the ROSE.INI file in your Windows folder and make sure that the
following sections contain paths to your Visual Modeler folder:
[Virtual Path Map]
SCRIPT_PATH=your_Visual Modeler_directory
[Visual Modeler 1.0]
MSVM_MENU_PATH="your_Visual Modeler_directory\Msvm.mnu"
MSVM_PTY=your_VM_directory\Msvm.pty
2. Q. What are the prerequisites to be able to run Visual Modeler
efficiently?
A. Operating system: Windows 95, Windows NT
Disk space: 30 MB(plus 20MB during installation)
RAM: 32 MB
Related Software:
Round-Trip Engineering: Microsoft Visual Basic 5.0 Enterprise Edition
Configuration Management: Microsoft Visual SourceSafe 5.0
Documentation Reports: Word 7.0
Web Access: Internet Explorer
Editing Diagrams and Classes1. Q. I can't paste classes into my diagram. Why? A. You cannot use the Paste command to insert classes into three-tiered diagrams. The reason is that it is not clear into which of the tiers the class should be inserted. You cannot use the Paste command in a Package Overview diagram for a package either, because that diagram can, by definition, only contain classes that belong to the package. The Paste command would therefore relocate the pasted class from the package where it was copied to the package that owns the Package Overview. Because that might not be what you wanted to do, the command is not available in those diagrams. 2. Q. When executing the Class Wizard, the message "The Class Wizard could not be found" is displayed. Why? A. In some configurations there may be problems registering DLLs used by Visual Modeler. To register the DLLs, run regmsvm.bat from the directory in which Visual Modeler is installed. Generating Code1. Q. When executing the Code Generation Wizard, the message "The Code
Generation Wizard could not be found" is displayed. Why?
A. In some configurations there may be problems registering DLLs used by
Visual Modeler. To register the DLLs, run regmsvm.bat from the directory
in which Visual Modeler is installed. Then the Wizard should be able to
execute.
2. Q. How do I control and preview what code to generate for a class?
A. The code generator uses the code generation options defined for each
class, property, association role, and method to make the mapping of
model components to Visual Basic code. In the Code Generation Wizard you
are able to define this mapping. That is, the Wizard allows you to
change the code generation option values for the selected classes and
their properties, roles, and methods. It also gives you a preview of the
code that will be generated with the current code generation option
setting.
To simplify, the Code Generation Wizard lets you define the most common
and important code generation options. However, the code generation
options for a class, property, association, or method are available on
the Visual Basic tab in its specification dialog. You can view and
change all of the code generation option values in this dialog. By
default, a predefined set of code generation options is attached to each
new model component. You can change that to another set on the Visual
Basic tab.
3. Q. How is inheritance (Generalization Association) in Visual Modeler
mapped to Visual Basic code?
A. Inheritance means that one class shares its properties, methods, and
relationships with another class or conforms to the interface of another
class. In Visual Basic, the closest correspondent to the generalization
relationship is the implements construct. Thus, for a generalization
relationship between a subclass B and a superclass A, Visual Modeler
generates the following code into B’s class module:
- An Implements A statement.
- An object of the superclass.
- Copies of A's public methods, including default dispatching
implementations that delegate to the parent class A.
Note that implements means only conformance to the public interface.
Thus, B inherits only A’s public methods, not the private methods. Also,
if a class C implements B, C does not implicitly implement A, because
the implementation of A’s public methods in B becomes private in B. Note
that inheritance between class utilities in Visual Modeler do not result
in any Visual Basic code.
4. Q. I have generated code with some GenerateGet, GenerateSet, or
GenerateLet code generation options selected. Why are they deselected
after the code generation?
A. They are deselected because the Code Generation Wizard creates the
Property Get procedure both in Visual Modeler and in Microsoft Visual
Basic. When the procedure is created, the corresponding GenerateGet code
generation option is reset.
5. Q. How do I change the implementation type of a class?
A. Once you have generated a class, you cannot alter its implementation
type in Visual Modeler. Thus, the Edit:Change Into command cannot be
used on classes or class utilities that you have generated code from. If
you want to change a class module into a module, for example, you have
to create a new class in the model, then copy the necessary information
from the original class, set its implementation type to "Module," delete
the original class, and generate code for the new class.
6. Q. I moved or copied a method from one class to another in the model and
generated code. Why is the new method body in the Visual Basic project
empty?
A. When you move or copy a method from one class to another, Visual
Modeler regards the method as a new method in the other class. When
generating code for a new method, the method body always becomes empty.
Thus, if you have to move a method from one class to another, do it in
Basic project and not in the model.
Reverse Engineering1. Q. When executing the Reverse Engineering Wizard, the message "The Reverse Engineering Wizard could not be found" is displayed. Why? A. In some configurations, there may be problems registering DLLs used by Visual Modeler. To register the DLLs, run regmsvm.bat from the directory in which Visual Modeler is installed. 2. Q. The ActiveX component I need to reverse engineer does not show up on the Selection of Components page of the Reverse Engineering Wizard. Why? A. To add it to your Visual Basic project, click References from the Project menu in Visual Basic and select the missing ActiveX component. Visual Basic 5.0 Integration1. Q. How do I reuse Visual Basic components in my model? A. By reverse engineering Visual Basic ActiveX components into your model, you can access and reuse their interface classes from other classes in your model. Simply click Reverse Engineering Wizard on the Tools menu in Visual Modeler and select the ActiveX components you want to insert into your model. 2. Q. I get the error message "VB5 not installed" even though it is installed. Why? A. If you have never run the Microsoft Visual Basic 5.0 program after installing it, Visual Modeler might not be able to localize the installation. In that case, run Microsoft Visual Basic 5.0 once. Configuration Management1. Q. Nothing happens when I execute the SourceSafe commands on the Tools menu. What is wrong? A. For Visual Modeler to be able to access Microsoft Visual SourceSafe, your installation of Visual SourceSafe has to contain the SourceSafe Integration component. Make sure that this component is installed by running the Visual SourceSafe setup program. Click Add/Remove and select the Enable SourceSafe Integration option on the Maintenance Mode page. (Note that this option was not selected if your installation was done via the "Server" alternative.) 2. Q. How do I version control a model? A. Visual Modeler includes an integration with Visual SourceSafe by providing the most frequently used SourceSafe commands on the Tools menu in Visual Modeler. Thus, you are able version control a model by using the usual Check In and Check Out commands. If you want to use another configuration management tool, you can integrate with that tool by updating the SourceSafe submenu. More information is found in the Visual SourceSafe Integration section of the "Round-Trip Engineering in Visual Modeler" Online Book. General1. Q. How do I control the appearance of a diagram?
A. The commands on the Diagram Object Properties menu (located under the
Edit menu) can be used to customize various Visual Modeler features.
The characteristics you set with this menu affect only the selected
icon(s). Setting the same characteristics through the Options dialog box
(located under the Tools menu) affect future items created on the
diagram. To organize the classes on the diagram automatically, click the
Layout Diagram command on the Tools menu.
You will also find some useful options on the Diagram tab in the Options
dialog box under the Display and Grid sections.
2. Q. How do I control the type of relationships to display in a diagram?
A. There are several ways to control the types of relationships to
display in a diagram. To control which kind of relationships to show for
the current classes in a diagram, use the Filter Relationships command
on the Query menu.
To show generalization relationships between classes in the diagram and
classes that are not part of the diagram, select the classes in the
diagram and click Expand Selected Classes on the Query menu. To control
which relationships to show for the classes in the diagram, as well as
for all classes that you create or paste in the diagram from now on, use
the Options command on the Tools menu. Then select the proper options on
the Diagram tab of the dialog box shown.
3. Q. How do I control whether to display properties and methods for the
classes in a diagram?
A. To control whether to show properties and/or methods for selected
classes in the diagram, point at the Diagram Object Properties command
on the Edit menu, and click the appropriate command. To control whether
to show properties and/or methods for the classes in the diagram, as
well as for all classes that you create or paste in the diagram from now
on, use the Options command on the Tools menu. Then select the
appropriate options on the Diagram tab of the dialog box shown.
4. Q. What is the difference between the Delete and Delete from Model
commands?
A. The Delete command only deletes the model component from the current
diagram. However, the model component is still available in the model
from the browser and you can insert it in other diagrams. The Delete
from Model command, on the other hand, deletes the model component from
both the current diagram and the model itself. The model component is
not accessible any more after that.
5. Q. What is the difference between logical view, component view, and
deployment view?
A. The logical view describes the logical structure of the system (the
classes and their relationships). The component view describes the
physical structure of the system (how the system is divided into
.exe files and DLLs). The deployment view also shows the physical
structure, but focuses on connections between the system’s nodes and
the allocation of processes to nodes.
6. Q. Why did I loose my associations? I had a class "tree" associated with
a class "fruit" in package A. I created another package B. I did
Query:Add Classes in package B and added the classes from the old
package. Then I "relocated" each of the classes. I then removed the old
package because it was empty. In the new class package the association
is missing.
A. Visual Modeler has "model elements" that include classes and
associations. The model elements are "owned" by the class packages in
which they are created. Model elements can be "relocated." You relocated
the classes but did not relocate the associations, so when you deleted
the class package you also deleted the association. You should have
selected the associations and relocated them also.
7. Q. How do I recover lost classes? Classes appear in the model
specification, even though I deleted them. Why?
A. There are two kinds of delete in Visual Modeler. There is the
Edit:Delete that is the shallow delete and simply deletes the displayed
item from the diagram; the item still remains in the underlying model.
The Edit:Delete From Model deletes the item from the model. When you
print out the specification for the entire model, all the shallow
deleted classes will still show up in the specification.
8. Q. How can I clone a class?
A. Occasionally you may need two classes with the same properties and
methods but just a different name. You can do an Edit:Copy of a class,
but because Visual Modeler has name-associations, the classes should
have unique names. Hence, after you copy a class, any changes you make
to one class will reflect on the other. The work around for this
situation is as follows:
- Select the class you wish to clone.
- Do an Edit:Copy on this class. A copy of this class is now being
maintained on the clipboard.
- Change the name of the class currently displayed on the diagram to
whatever you wish, other than the one you already copied.
- Do Edit:Paste. You now have two classes, both with the same
underlying state and behavior but two different names.
9. Q. Can I suppress the data type of properties that appear in the class
icon the same way I suppress the method signatures?
A. No.
REFERENCESVisual Modeler Help files
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Additional query words: Visual Modeler
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