WMS Notes

WMS Notes is a hierarchical (tree-based) note-taking application.

Features:

• A hierarchy of notes and folders
• Synchronization across desktop and Android phone, enabling offline note editing
• Note-taking in Markdown format
• Image attachments

The application consists of three parts:

• A desktop application for Linux, Windows and macOS
• An Android app
• A server application for Linux, Windows and macOS

Technical Details

WMS Notes has been used to try out several approaches and technologies, including:

• Event sourcing and CQRS
• Reactive extensions (specifically RxJava, RxKotlin and RxAndroid)
• JavaFX (and the TornadoFX framework for Kotlin)
• Protobuf + gRPC
• Android development
• Kotlin

Besides the technologies mentioned above, the project also uses:

• Spring Boot
• Kryo (serialization framework)
• JUnit 5
• MockK (Kotlin mocking framework)

The Markdown editing and previewing panes have been gratefully taken from Markdown Writer FX.

Event Sourcing and CQRS

Here are some good articles on event sourcing:

• Design of an CQRS/ES system: https://hackernoon.com/1-year-of-event-sourcing-and-cqrs-fb9033ccd1c6 (contains links to other good resources as well)
• On dealing with concurrent updates: https://medium.com/@teivah/event-sourcing-and-concurrent-updates-32354ec26a4c