Software design

Component design

Software design is based on Shape component framework.

The framework itself is just a glue to put all components together. However, it allows flexible adding of other features or redesign existing. The business logic itself is implemented in components described in this document.

The framework is described here. It follows basic principals as defined here.

Principles

Module is distributable software in a form of shared library. Includes components data classes and logically merges related software parts.

Interface is pure virtual (abstract) class containing methods (functions). Used parameters should be general not exposing implementation details.

Component is class which implements Interface. There can be more components implementing the same Interface. E.g. component logging to file and component logging into database. Both can implement the same Interface. Component may use other Interfaces implemented by other Components.

Component Instance is an object of a component created by the component constructor. Number of created Component Instances depends on an application configuration. E.g. file logging component can have three instances, one for critical errors, second for debug level and third for a specific component.

Provided Interface is running Component Instance implementing the Interface published to be used.

Required Interface is published placeholder for required Interface. If a Component Instance wants to use an Interface it publish the placeholder.

Attach Interface is delivering Provided Interface to Required Interface placeholder.

Detach Interface is withdrawal of Provided Interface to Required Interface placeholder.

Interface Cardinality is SINGLE or MULTIPLE. It means Required Interface instance can be attached just once or all instantiated Interfaces can be attached.

Interface Optionality is UNREQUIRED or MANDATORY. It means all MANDATORY Interfaces have to be attached.

Interface Target is UNREQUIRED or MANDATORY. It means all MANDATORY Interfaces have to be attached.

Activate is a Component Instance state when all MANDATORY Required Interfaces were attached and the instance is set by Shape to normal operation.

Deactivate is a Component Instance state when some of MANDATORY Required Interface was detached and the instance is set by Shape to stop normal operation.

Service is represented by its Interface. Provides service like doing command, send data, parse data, calculate data, registering call-back, etc. Service is a published Interface (Provided or Required) within Shape framework.