I am a student and we have a Object-Oriented Project that we have to do to pass Object-Oriented course. My problem is to design the project. Teacher wants two different class diagram.Teacher said "One is high level, other one is normal class diagram." I know that high-level class diagram have detailed information such as attributes and methods. Additionally, I think high-level diagram covers normal diagram. What is normal class diagram? What is the difference between high-level and normal class diagram? I think that if we draw a high-level diagram normal diagram is redundant. Why Did teacher want normal diagram? I am confused.
There are typically 5 "levels" of design that one should think of, so that is where the "high-level" comes from. They are usually like this:
Software System - This is where you think of the software in terms of entire packages, or in terms of its subsystems.
Subsystems - This is the part where you ID all of the major subsystems, such as database, user interface, reporting engine, etc. This is the part where you define how each subsystem uses one another, and how they work together.
The first two are probably what your teacher meant by "High Level Design".
Classes - This further partitions the subsystems by classes. For instance, if you had a database system, you might have a class that manages the persistent connections, the metadata, etc. The way each class works with classes in other subsystems are also defined. This is probably what your teacher means by "class design".
Below that, you further divide each class into routines and internal routines, but I assume your teacher does not want you to get that detailed. However, for completion's sake, I will define them:
Routines - Design at this level includes dividing each class into routines. It is the "how" to the "what" answered in level 3.
Internal Routine - Design of the individual routines.
Related
We have a complex class model of clinical information. It's intended to support model-driven architecture, so the we can't just defer the complexity. But we also need subject matter experts to be able to review it. Is there a way in UML to create "views" like you would in SQL?
In a diagram, you show only classes you want and you get several diagrams to present all points you need.
Your UML model contains all classes, but in a diagram you present only classes you want.
There i a specific UML meta-class for your purpose : Model which inherits from Package.
"A Model is a description of a system, where ‘system’ is meant in the broadest sense and may include not only software and hardware but organizations and processes. It describes the system from a certain viewpoint (or vantage point) for a certain category of stakeholders (e.g., designers, users, or customers of the system) and at a certain level of abstraction. A Model is complete in the sense that it covers the whole system, although only those aspects relevant to its purpose (i.e., within the given level of abstraction and viewpoint) are represented in the Model." p 245
And
" A model captures a view of a physical system. It is an abstraction of the physical system, with a certain purpose. This purpose determines what is to be included in the model and what is irrelevant. Thus the model completely describes those aspects of the physical system that are relevant to the purpose of the model, at the appropriate level of detail." p 273
And it shown like :
But to do like view, meaning to present to user a "public" view of a complex model, you have to use some patterns like :
facade
mediator
So I have to make a class diagram for a Unity game I made as part of a project.
Trouble is I have to make a class for every script, of which there are 60.
The guidelines given to me simply states: Create a class diagram of your game.
So should I be splitting this up into several different class diagrams or literally just one inevitably disgusting 60 class diagram?
Your guidelines already told you what to do for this project: "Create a class diagram of your game." If this is a class project, create a single horse blanket, make your professor happy, and get a good grade.
However, on a real-world project, you should create many micro-subject-area diagrams for your audience. Review with each person only the diagrams that matter to them. That's how you (and your victims) can survive very large projects.
To create micro-subject-area diagrams, create a set of diagrams, each containing 7 ± 3 classes. Every class has only one fully-defining diagram showing all of its compartments and associations. Everywhere else, the class should appear only with its class name (to help define other classes) and a hyperlink. The hyperlink makes it work like an edge connector that takes you to its fully-defining diagram. (If you use MagicDraw, there is a free plug-in available, called AutoStyler, that automates this.)
It is legitimate to split up class diagrams, as class diagrams are meant to clarify things, which a gigantic mega class diagram arguably does not do. As such, class diagrams should usually concentrate on a few specific aspects that you want to show:
Do you want to provide a detailed structural representation of a given set of classes? If so, only depict these classes with all members, but skip any other classes (e.g., do not draw them as class nodes, but instead just mention their names as member/parameter types where appropriate).
Do you want to provide the class structure related to a particular functionality? If so, draw the relevant set of classes, but skip irrelevant members (e.g. members that have to be there for the sake of infrastructure support, but that are not a part of the actual business logic you are focusing on).
etc.
Now, when there is any expectation of completeness rather than a mere overview, it needs to be clear what parts of the diagram are complete and which ones are abbreviated. Again, this is possible in various ways:
As in the first bullet item above, mentioning a type name without drawing it is a clear indication that there is another type that is not depicted in the current diagram, without making the depicted class incomplete.
Alternatively, you can make use of "natural boundaries by abstraction" in your code: If you use classes from an extensive hierarchy, it may be sufficient to draw only the base class, or a few general base classes, in one diagram, while detailing the actual class hierarchy (without any of the context from the other diagram) in a separate diagram.
Two remarks on your specific question:
In your case, "60 scripts" sounds like various of them may easily fall into the last case, allowing you to separate overall architectural diagrams from a class hierarchy diagram.
You say there are "guidelines". If this is for some kind of competition or for any other kind of evaluation (e.g., for studying), take all this advice with caution: Internal grading guidelines might not necessarily be congruent with what would be practical/useful in an actual project.
tl;dr
Create as many class diagrams as you need
Avoid wallpaper diagrams only
Create wallpaper diagrams, though. But assemble them from existing diagrams.
Try to spot sub-domains (things that belong together) and place them in one diagram
Why and how are dependency relationships used?
I've come across a PiggyBank example where the Analysis Model consists of a class diagram with dependency relationships.
They use two relationships "use" and "instantiate" to describe the relationships between the classes.
I don't agree with the relationship that the boundary class TransferMoneyForm has a "use" to the TranferMoneControl. I believe it should be the other way around.
Can someone exaplain to me how these two relationships should be used. Thank you in advance.
The diagram shown there is not a correct and full UML class diagram. In such all the associations and generalizations should be defined, and what is abstract, what is public or not. To show what descends from what, what is hidden, what will be never instantiated and what fields of one class has types of other classes. Here we see only information about the
functions.
And it is logical. If you'll look at the previous chapter, there is written: "A control class represents a self-contained process..." So, they are talking on processes, not classes, instances and fields.
It is NOT a class diagram. And nowhere is said that it is. It is named "Transfer Money Participants diagram". They do use the elements of the class diagram, but not to the fullest and so create something more common. It is some approximate undefined diagram on some classes, something between class, communication or component diagrams. Maybe, it is the old style of IBM? Experts (What's the best UML diagramming tool?, 1st answer) say, "IBM Rational Software Architect did not implement UML 2.0". )
As for the question, who uses whom... According to Sparx VP UML, a "usage dependency" is a "relationship in which one element requires another element ... for its full functionality". According to wiki, "The client element somehow "uses" the supplier". Here the form hasn't sense without the controlling class, and vice versa. So, I'd say, the use goes in both sides. But more honest would be to create a normal communication or component diagram. The class diagram has NOT an element to say about sending and accepting the messages. And the "use" is definitely not for it. And when they have decided not to use logic, they can put there virtually anything.
If you are making a class diagram and one your class uses function(s) of another one, that is the case to draw a use dependency connection.
As we know in OOP that interface provides a set of operations without implementation but
class is the opposite.
in Object oriented design ,we use uml the interface has a set of operations without implementation
and the class also has a set of operations without implementation(i know class has attributes in addition to its operations)?
so, what is the difference in UML?
As we know in OOP that interface provides a set of operations without implementation but class is the opposite.
Not quite true - abstract classes are classes that have one or more methods declared but not defined (in C++ and Java these are abstract methods). You can have a class defined with all its methods abstract - in which case there is close similarity with an interface.
One key idea in UML, though, is that an interface is a set of methods exposed to other classes or components. The purpose is to define a set of operations.
However, moving to programming, a method may be made abstract to aid development (e.g. by ensuring all subclasses have an implementation). This method might be purely internal to the class.
One last observation: the term interface and class in UML are not quite synonymous to interface and class in a language, say Java. For example, Java does not allow multiple class inheritance. Instead Java has the interface which allows a class to implement multiple types (not classes - a subtle difference)
EDIT
Quick note technical words:
Declare: Stating to the system that a variable or operation exists and its type or signature
Define: Same as declaring, but additionally providing a complete implementation of a variable or operation
Interface: A set of declarations of operations
Type: An object's interface(s) and other operations
Class: An object's class defines (not declares) how the object is implemented, including its internal state and the implementation of its operations
Define is to Declare as Class is to Type.
(see What is the difference between Type and Class?)
The purpose of interface is to define a set of operations but we are do the same for class also define a set of operations?
So the purpose of the interface is to declare (not define) a set of public operations that other objects want to use. A class (in UML) is the complete set of operations (public and private). A class (in Java, C++, etc.) additionally defines all non-abstract operations.
So the key is the intent: When other components of the system want to use a set of operations, use interface. When you're using UML to describe an implementation (of a component, algorithm, etc.) use class.
when I go to class that assumed to implement those operations I can't see any implementation for those operations as a diagram describe those operations or anything give a sign for implementation?
UML tool is for modelling and so deliberately avoids providing a place where you enter operation definitions - that is left for later. The idea is that you:
Define the model in UML
Use the UML tool to generate code in the target language
(And some allow you to import your code back into the tool to modify the model with any changes made during implementation. This is called "round-trip" modelling, something which the old TogetherJ product excelled at)
This deliberate gap (you might say deficiency) means that 'define' vs. 'declare' in UML is meaningless. Sorry.
Perhaps you've just seen models created for describing an overview, rather than modelling the system fully, but you can model the behaviour of a class's operations in most UML tools, and some tools also model the behaviour sufficiently that it can be executed .
The behaviour associated with an operation can be modelled using UML state machines, using UML action semantics or in several other ways. Quite often this is left out of the model - it is not always useful to go to that level of detail, so the implementations may just be hinted at in the documentation associated with the operation. But concrete classes in UML definitely have concrete behaviours associated with their operations, so the difference between UML and programming is that UML focuses on behaviour rather than implementation.
According to Wikipedia -
Unified Modeling Language (UML) is a standardized general-purpose
modeling language in the field of object-oriented software
engineering. The Unified Modeling Language includes a set of graphic
notation techniques to create visual models of object-oriented
software-intensive systems.
So, most important thing is UML is general-purpose and graphical. It is not only about classes and interfaces.
UML offers a standard way to visualize a system's architectural blueprints.
Software Construction Needs a Plan. Structure diagrams, Behavior diagrams, Interaction diagrams helps to Visualise In Multiple Dimensions and Levels of Detail which is
Appropriate For Both New and Legacy Systems.
Unified and Universal, Accommodates Parallel Development of Large Systems.
When I think of UML, one term which comes to mind is software quality. One thing that has plagued the software industry in recent year is poor software design. While the software industry has done fairly well for the last decade, the impact of globalization is changing the ways in which software is designed.
I have a program I made in C++ that does not use classes, just simply functions and main().
I want to know what kind of diagrams I can draw for it. Here are a couple of things I have in mind.
Activity diagram
Sequence diagram
class diagram - obviously can't draw this because I didn't use classes
system architecture
state diagrams
use case diagrams
Out of these what can I draw?
I'm guessing from the diagrams that you are aligned to a * Unified Process approach.
IMHO:
Use Case - definitely - eliciting business and system level requirements is implementation agnostic
System Architecture - definitely - layers, processes, network, db and modules / packages.
Activity Diagrams - definitely - use this to describe process flows for key processes
State Diagrams - applicable, although usually associated with the state and lifespan of a single object instance, but it is still conceptually useful if you are maintaining state through other means
Sequence Diagram - applicable, although you will probably need to provide an arbitrary class name to attach your functions (if you are using namespaces, then possibly aggregate to these these instead?)
However, you might hit issues if you want to generate and round-trip code from your diagrams e.g. from a CASE tool such as Rational Rose - most will assume an OO implementation language (noting that the three Amigos are strongly associated with OO!)
I guess this begs the question as to why you would need to develop a procedural app using an OO language and document it with OO techniques?
HTH
As a generalization: You can use all types except the class diagrams. If you could draw a class diagram, you should ask yourself, why you did not use classes in this case.
For all other diagrams, you can use parts of your app as "actors" or "components". It seems like you have not researched yet what these diagrams are used for and what you express with them. If you do that you should be able to determine which diagram makes sense for you.
Remember that each diagram should have a purpose. If you do it just for the sake of being there, then don't do it.