UML Class Diagram Help
UML Class Diagram Drawing Software - ClassDraw. An association is a relationship between two classes represented by a solid line. In the example, the OutputDevice interface is implemented by the Printer and Monitor classes. Interface. Stack-Printer Object Diagram do not ﬁnd it easy to use because of the lack of a well deﬁned model design tion tool  for a subset of the UML, namely class, object, state and UML structural and behavioral diagrams. . elements, such as classes, relationships, attributes and operations into ASM. In software engineering, a class diagram in the Unified Modeling Language ( UML) is a type of It is printed in bold and centered, and the first letter is capitalized. Aggregation is a variant of the "has a" association relationship; aggregation Generalization can only be shown on class diagrams and on use case diagrams.
In the example, the Customer class knows about any number of products purchased but the Product class knows nothing about any customer. An alternative to using role names is to provide a single name for an association centered between the two classes. A direction indicator can also be used to show the direction of the name, but is not necessary if the direction is obvious: An association can also link a class to itself.
Such an association is reflexive: Aggregation Aggregation is a relationship where one class is part of another class.
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In basic aggregation, the class that forms part of the whole class can exist independently, so the life of an instance of the part class is not determined by the whole class.
Basic aggregation is represented using an empty diamond symbol next to the whole class. In the example, a computer in a warehouse contains a motherboard, but although the motherboard is part of the computer, it can exist as a separate item.
In this system, Computer knows about Motherboard but Motherboard doesn't know about Computer, so the aggregation is unidirectional. In a program, this relationship could be implemented as a member variable in the Computer class which is a reference to a Motherboard class.
Association differs from aggregation only in that it does not imply any containment. Composition Composition is a strong type of aggregation where the whole class contains the instance of the part class. The lifetime of the part class depends on the existence of the whole class. Composition relationships are represented using a filled diamond symbol next to the whole class.
In the example, a building contains a number of rooms and a room cannot exist without a building. If a Building class instance is destroyed, its Room class instances are destroyed too. In a program, this relationship could be implemented as a member variable in the Building class which is an array of Room classes and the Room class might contain a pointer to a Building class.
Dependencies A dependency is a weak relationship between two classes and is represented by a dotted line. In the example, there is a dependency between Point and LineSegment, because LineSegment's draw operation uses the Point class.
It indicates that LineSegment has to know about Point, even if it has no attributes of that type.
Class diagram - Wikipedia
Right-click an element on the diagram, and from its context menu, choose Properties. The Properties window displays both visual and semantic properties. Select the diagram element. Select the property to change.
On the right of the Properties window, select the control and change the value. The control may be an edit box, a drop-down list, a checkbox, etcetera.
If a single element is selected all valid properties are available; it multiple elements are selected, only the properties valid for all elements are selected. Alternatively, on the tool bar, select the font type, font size, or color box, then make the required change. Another option is to choose Visual Properties from the context menu, then make the required change. How to Change the Visual Properties of New Diagram Elements Use the Preferences dialog to define the default visual properties of any elements you add to your diagrams.
To change the default setting of diagram elements to be added to a diagram: The preferences might be displayed on a single panel or multiple tabs.
Change the default values as you require, and click OK. To copy and paste visual properties to elements: Select a diagram element. Right-click and select Copy Graphical options from the context menu.
Select the target element s.
Annex A: UML (Unified Modelling Language) Notation
Right-click and select Paste Graphical Options from the context menu. How to Resize Elements on a Diagram Resize an element by dragging the grab bars until the item is the size you want. Some diagram elements cannot be resized, such as initial and final nodes. Certain element types also have internal grab bars, that are displayed when an element is selected.
These internal grab bars are for resizing the compartments of those diagram elements. Whenever a diagram element is resized towards the visible edge of the diagram, the diagram is automatically scrolled. New diagram pages are added where an element is resized off the diagram surface.
To resize a diagram element: Select the element to resize. Position the pointer on any grab bar on the element and hold down the mouse button.
The pointer is displayed as a double-headed arrow when it is over a grab bar. Drag the grab bar until the element is resized, then release the mouse button.
How to Display Related Classes on a Diagram Classes and interfaces related to those currently displayed on the diagram can be brought onto the diagram. This includes classes or interfaces that are extended, implemented, or referenced by the selected class or interface. Choose from the following options to display related classes on a diagram: How to Move Diagram Elements Dragging elements on the diagram surface is the easiest way of moving elements.
To move elements over a larger areas, cut and paste. Whenever a diagram element is moved towards the visible edge of the diagram, the diagram is automatically scrolled.
New diagram pages are added where an element is moved off the diagram surface. To move diagram elements: Select the element, or elements to move. Position the pointer on the elements, then press and hold down the mouse button. Drag the selected elements to their new position. Release the mouse button. If an element overlaps another element they are displayed on top of one another.
Right-clicking the element and choose Bring to Front to view. Graphical actions change the appearance of elements on the diagram surface and include the following: Cutting and pasting elements on diagrams.
Altering the position and size of diagram elements. Changing the font, color, and line width of diagram elements. Changes to an element's semantic properties can only be undone if the technology Java, for example permits it. Changing an element's semantic properties might prevent previous graphical changes from being undone. To copy elements from a diagram and paste them into another diagram: Select the diagram elements, then choose Copy on the context menu, or choose the Copy icon on the toolbar, or press Ctrl-C.
Open the destination diagram. Place the pointer where you want the diagram elements to be added, then choose Paste from the context menu or choose the Paste icon on the toolbar, or press Ctrl-V. How to Rename a Diagram Renaming changes the diagram name without leaving a copy of the original. To rename a diagram: In the Applications window, select the diagram to rename. How to Publish a Diagram as an Image Use the right-click context option to publish your diagram as a graphic image.
You can preview and print your diagram once it is published as an image. To publish a diagram as an image: Right-click your diagram, then choose Publish Diagram. Select the destination folder from the table for the image file.
In the File name box, enter a name for the image file, including the appropriate file extension svg, svgz, jpg, or png. How to Setup a Page for Printing Change from portrait to landscape or your margins for printing using page setup. To setup the page before printing: Make changes to the settings on the tabs of the Page Setup dialog. How to Set the Area of a Diagram to Print Set a specific area of your diagram to print using set print area off the File menu option.
To set the area of the diagram to print: On the diagram, drag the mouse pointer to enclose the objects on the diagram to print. The area to print is shown with a dashed outline. If you do not set an area, then the whole diagram is printed.
You can also set print options from this page by choosing Print Options. On the Print Option page you can add header and footer content as well as text formatting. When you are using the thumbnail view, use scroll to zoom. There are also zoom options on the diagram toolbar.
How to Delete a Diagram Delete the diagram and related diagram elements using the menu bar. To delete a diagram: In the Applications window, select the diagram to remove.
These commands remove the diagram file from the system and close the editing window for that diagram. The elements for the deleted diagram remain in the applications window and on the file system.
You can also delete a diagram from the Applications window. In the Applications window, right-click on the diagram name and choose Delete.
Working with Diagram Layout Diagrams can be laid out in hierarchical, symmetrical, grid, and row styles. Elements within your diagrams can also have customized layout styles. There are many preferences available to customize the way you diagram looks. From the general preferences dialog you can choose Edit Preferences for to set specific preferences for new diagrams. Figure Class Diagram Visual Properties How to Use a Hierarchical Diagram Layout Hierarchical layout puts diagram elements in hierarchies based on generalization structures and other edges with a defined direction, as show in Figure Nodes on a diagram that are not connected to any other nodes are laid out in a grid layout.
Hierarchical layout is available in four orientations: Oblique lines can be repositioned at any angle. Rectilinear lines are always shown as a series of right angles. Figure Diagram Preferences, Edit Preferences for Line Style You can also set the line style for all instances of that diagram type.
Class Diagram Tutorial
Keep in mind that when the line style of an individual edge is changed to oblique, and you change the line style from rectilinear to oblique, no change will be apparent on the diagram, but you will then be able to move any of the lines on the diagram into a new position at any angle.
You can select individual diagram edges and change their line style. If you change an individual line from oblique to rectilinear, the line will be redrawn using right angles. If you change an individual line from rectilinear to oblique, no change will be made to the line, but you can reposition it or portions of it at any angle.
You can also choose the crossing styles for your lines to be bridge or tunnel style. Selecting bridge creates two parallel lines where the lines intersect. Selecting tunnel creates a semi-circle shape on the intersection. The default style is a regular crossing over of the two lines where the lines intersect. How to Use a Symmetrical Diagram Layout Symmetrical layout aligns diagram elements symmetrically based on the edges between the nodes as shown in Figure Under certain circumstances, a symmetrical layout will position nodes in a radial layout around a central node.
Figure Symmetrical Diagram Example How to Use an Orthogonal Diagram Layout Orthogonal diagrams show hierarchical and non-hierarchical elements where the aligned edges of a component all follow the same direction, as shown in Figure Association represents the static relationship shared among the objects of two classes.
Aggregation[ edit ] Class diagram showing Aggregation between two classes.
Here, a Professor 'has a' class to teach. Aggregation is a variant of the "has a" association relationship; aggregation is more specific than association. It is an association that represents a part-whole or part-of relationship.
As shown in the image, a Professor 'has a' class to teach. As a type of association, an aggregation can be named and have the same adornments that an association can. However, an aggregation may not involve more than two classes; it must be a binary association. Furthermore, there is hardly a difference between aggregations and associations during implementation, and the diagram may skip aggregation relations altogether. The contents of the container still exist when the container is destroyed.
In UMLit is graphically represented as a hollow diamond shape on the containing class with a single line that connects it to the contained class. The aggregate is semantically an extended object that is treated as a unit in many operations, although physically it is made of several lesser objects.
Here the student can exist without library, the relation between student and library is aggregation. Composition[ edit ] Two class diagrams. The diagram on top shows Composition between two classes: A Car has exactly one Carburetor, and a Carburetor has at most one Car Carburetors may exist as separate parts, detached from a specific car.
The diagram on bottom shows Aggregation between two classes: A Pond has zero or more Ducks, and a Duck has at most one Pond at a time. The UML representation of a composition relationship shows composition as a filled diamond shape on the containing class end of the lines that connect contained class es to the containing class. Differences between Composition and Aggregation[ edit ] Composition relationship 1. When attempting to represent real-world whole-part relationships, e.