Possibilities for extending functionalities

[AleksandrDederer]

Is your feature request related to a problem? Please describe

I'm interested in extending some inventory-tool cli and core functionalities. Currently, there is not method available other that forking both repositories.

For example, I want to extend core GraphMergerImpl logic. This logic should be invoked from cli.

Unfortunately cli hardcoded instantiation org.qubership.itool.modules.processor.GraphMerger in the org.qubership.itool.tasks.ci.MergeGraphsVerticle

And I have no any abilities to override this logic. All I can is copy-paste whole MergeGraphsVerticle even we are talking about single line.

All I can is to copy-paste this MergeGraphsVerticle and change GraphMerger instantiation. But it means I need to fork both CORE and CLI repositories.

The same problem with the DiagramProvider. If I want to change/add DiagramProvider there is not method to do it.

All I can is to copy-paste all classes from the org.qubership.itool.cli.ci package and override AbstractCommand.configLoaded() method (need to change instantiation of the FlowContextImpl to the my new CustomFlowContextImpl class).

Describe the solution you'd like

Please provide a consistent and easy method for extending functionality in the CORE and CLI components.

Something like as a Plugin Management or Application Context + Dependency Injection solution.

Describe alternatives you've considered

No response

Additional information

Currently I'm blocked by the following codes:

qubership-inventory-tool-cli/src/main/java/org/qubership/itool/cli/AbstractCommand.java

Line 80 in 663f986

FlowContextImpl flowContext = new FlowContextImpl(graphService);

and

qubership-inventory-tool-cli/src/main/java/org/qubership/itool/tasks/ci/MergeGraphsVerticle.java

Line 46 in 663f986

try (GraphMerger merger = new GraphMerger(vertx, false)) {

[al-matushkin]

Some proposals for solution of highlighted issues can be found in related pull requests.

Solution for cli:
#42
This solution also involves changes in core:
Netcracker/qubership-inventory-tool-core#34

Short description of changes: instead of creation of instances of graph merger and flow context classes we can use dedicated factories which will be injected in needed classes. That should allow to cover a lot of customization cases while using CLI and Core libraries.

In case of GraphMergerFactory, the custom instance could be provided as a resource in custom FlowContextImpl, and for FlowContext itself the concrete extended implementation could be set in properties as you can see in default.properties file