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| <mainDescription><h3 align="left">
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| Modeling Components
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| </h3>
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| <p align="left">
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| The UML component is a modeling construct that provides the following capabilities:
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| </p>
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| <div align="left">
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| <ul>
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| <li>
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| Group classes to define a larger granularity part of a system
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| </li>
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| <li>
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| Separate the visible interfaces from internal implementation
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| </li>
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| <li>
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| Execute instances run-time
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| </li>
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| </ul>
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| </div>
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| <p align="left">
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| A component includes <strong>provided</strong> and <strong>required</strong> interfaces that form the basis for wiring
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| components together. A <strong>provided interface</strong> is one that is either implemented directly by the component
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| or one of its realizing classes or subcomponents, or it is the type of a provided port of the component. A
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| <strong>required interface</strong> is designated by a usage dependency of the component or one of its realizing
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| classes or subcomponents, or it is the type of a required port.
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| </p>
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| <p align="left">
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| A component has an external view (or <em>black box</em> view) through its publicly visible properties and operations
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| .Optionally, a behavior such as a protocol state machine may be attached to an interface, a port, and the component
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| itself to define the external view more precisely by making dynamic constraints in the sequence of operation calls
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| explicit. The wiring between components in a system or other context can be structurally defined by using dependencies
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| between component interfaces (typically on component diagrams).
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| </p>
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| <p align="left">
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| Optionally, you can make a more detailed specification of the structural collaboration by using parts and connectors in
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| composite structures to specify the role or instance-level collaboration between components. That is the component's
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| internal view (or <em>white-box</em> view) through its private properties and realizing classes or subcomponents. This
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| view shows how the external behavior is realized internally. The mapping between external and internal views is by
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| dependencies on components diagrams or delegation connectors to internal parts on composite structure diagrams.
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| </p>
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| <p align="left">
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| A number of UML standard stereotypes exist that apply to components, including &lt;&lt;subsystem&gt;&gt; to model
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| large-scale components, and &lt;&lt;specification&gt;&gt; and &lt;&lt;realization&gt;&gt; to model components with
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| distinct specification and realization definitions, where one specification may have multiple realizations.&nbsp;
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| </p>
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| <p align="left">
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| The recommendation is to&nbsp;use components as the representation for design subsystems.
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| </p>
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| <h3 align="left">
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| UML Definitions -- A History
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| </h3>
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| <p align="left">
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| The definition of <em>component</em> with the UML has changed over time with the release of different versions. The
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| version of UML you use may be constrained by the capabilities of the modeling tools you use. That is why the
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| definitions from 1.3 to 2.0 are provided here.
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| </p>
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| <p align="left">
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| UML 2.0 defined <em>component</em> as the following:
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| </p>
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| <blockquote dir="ltr" style="MARGIN-RIGHT: 0px">
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| <blockquote>
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| <p align="left">
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| ...a modular part of a system that encapsulates its contents and whose manifestation is replaceable within its
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| environment.
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| </p>
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| <p align="left">
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| A component defines its behavior in terms of provided and required interfaces. As such, a component serves as a
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| type whose conformance is defined by these provided and required interfaces (encompassing both their static as
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| well as dynamic semantics).
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| </p>
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| </blockquote>
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| </blockquote>
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| <p align="left">
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| UML 1.5 defined <em>component</em> as the following:
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| </p>
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| <blockquote>
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| <blockquote>
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| <div align="left">
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| A modular, deployable, and replaceable part of a system that encapsulates implementation and exposes a set of
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| interfaces. A component is typically specified by one or more classes or subcomponents that reside on it and
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| may be implemented by one or more artifacts (e.g., binary, executable, or script files).
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| </div>
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| <div align="left">
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| <p>
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| In UML 1.3 and earlier versions of the UML, the component notation was used to represent files in the
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| implementation. Files are no longer considered components by the latest UML definitions. However, many
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| tools and UML profiles still use the component notation to represent files.
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| </p>
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| <p>
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| <br />
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| <br />
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| &nbsp;
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| </p>
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| </div>
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| </blockquote>
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| </blockquote></mainDescription> |
| </org.eclipse.epf.uma:ContentDescription> |
