Riffle: Reactive Relational State for Local-First Applications

The reactive paradigm for developing user interfaces promises both simplicity and scalability, but existing frameworks usually compromise one for the other. We present Riffle, a reactive state management system that achieves both simplicity and scalability by managing the entire state of a web application in a client-side persistent relational database. Data transformations over the application state are defined in a graph of reactive relational queries, providing developers with a simple spreadsheet-like reactivity model. Domain state and UI state are unified within the same system, and efficient incremental query maintenance ensures the UI remains responsive. We present a formative case study of using Riffle to build a music management application with complex data and stringent performance requirements.