48 lines
2.2 KiB
Text
48 lines
2.2 KiB
Text
The Application Realm
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=====================
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// Menu : prepend child ApplicationStart
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Shaping the outside world through software requires a variety of effective mechanisms
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that capture, represent, and transform elements of reality. A well-designed part is
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focused on a single aspect, is coherent and cohesive in itself, with links to other
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parts based on concepts and abstraction rather then on shared technology. Yet this
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structural perspective must be complemented by a meaningful overall arrangement that
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supports the desired workflow and can be adapted to circumstances.
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In software systems, such coherency does not emerge spontaneously. It must be supported
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by definition work to establish suitable terms and interfaces, components must be
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interconnected and configured, and the overall state needs coordination.
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An application is therefore more than just a collection of software components.
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In the Lumiera Architecture, this application realm is embodied into a structure
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called the »**Vessel**«:
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- it is built as a library with only basic linkage to the support library
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- it can be invoked from a `main()` function, with an argument parser
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- at source code level, it provides all the types and definitions
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required to express the _binding_ between components
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- _conceptually,_ all layers are encased in the _application vessel_
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- and while the Vessel can not just ``control'' the configuration of parts
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on upper layers, it has to bootstrap their ability to adapt to circumstances.
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--
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--
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Dependencies::
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While the code base is organised into _three layers,_ the actual implementation
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structures are arranged into **Subsystems** that _depend_ on each other and
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can be _started and shut down_
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+
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-> link:ApplicationStart.html[Subsystems and Lifecycle]
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Configuration::
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As a means to adapt to the environment and enable flexibility,
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this topic is surprisingly intricate and development has barely scratched
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the surface: while the effective configuration is assembled from several
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layered sources, the meaning (and documentation) of individual settings
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is scoped, and users can expect the ability to override some settings
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from within the application.
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+
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-> link:Config.html[Configuration]
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