Guide for Developers

Thorium is built on a number of technologies and tools:

Be sure to learn about these technologies before diving in too deep.

Thorium also uses a number of patterns, such as:

  • Event Sourcing
  • Subscriptions and PubSub - this provides reactive updates to the frontend views.
  • Dynamic frontend views which change and respond to backend data. This is what allows Thorium to dynamically change what simulators, stations, and cards show on an individual client.

Thorium uses a unique vocabulary:

  • Simulator: a virtual representation of a spaceship or other vessel. Simulators have StationSets, Stations Systems, Crew, Decks, Rooms, Inventory, etc. Examples of Simulators include the USS Voyager, USS Odyssey, etc.
  • Station: an individual grouping of Cards. Belongs to a Simulator. Stations have Cards. Examples of stations include Helm, Tactical, Command, Communications, Operations, Engineer, etc.
  • StationSet: a group of stations for a specific Simulator. Simulators can have multiple StationSets for different groups and missions. For example, you can have a station set for 8 crew members, 12 crew members. You can have a station set for school flights (with simpler cards) or you can have a level-3 station set for experienced groups.
  • Card: an individual screen. Typically control a single aspect of the simulator. Belongs to at least one Station. Examples include Targeting Grid, Engine Control, Thrusters, Security Teams, etc.
  • System: a representation of the capabilities of a simulator. Systems are assigned to Simulators. Each system is different and unique and is individually developed.
  • Mission: a timeline of events which happen during the course of a simulation. Missions have timeline items which execute Macros.
  • Macro: An atomic, scripted operation with an event and arguments for the event. Belongs to Mission.
  • Client: A representation of an individual computer connected to Thorium. Tracks information about that specific client, including the login state, the login name, the offline state, etc. Also tracks the Flight, Simulator, and Station assigned to the client.
  • Flight: an individual instance of a simulated experience. Flights have at least one Simulator (which you select a StationSet and [optionally] a Mission on).
  • Set: a representation of a physical configuration of Client computers. Used to quickly and automatically set up the Clients with information about their Flight, Simulator, and Station based on the Simulator and StationSet
  • Asset: an image associated with some information in the simulation. Organized in Folders and Containers. Examples include Sensor Contacts, Ship Images, Comm Images, etc.

Please open an issue if you find another term that needs a definition

Event Sourcing

For the backend data, Thorium uses Event Sourcing to track data throughout the simulations. An event describes something which happened in the simulation. Events have arguments which describe how the event happened. Examples include 'Phaser Fired', 'Warp Engines Activated at Warp 3', 'Navigation System Damaged'.

Events are queued either through GraphQL mutations or internal processes. Typically, mutations just queue events without any kind of processing. Mutations also do not return any data. Events are fired async.

Events are stored in a log of events which can be audited at any time in the future. Events are triggered immediately after they have been queued. The event handlers then perform any actions necessary, such as updating information in an in-memory data store or sending notifications to a client.

The most important aspect of the event handler is the subscription publication. This sends an update to a specific channel about updates to the data which were caused by the event. Clients subscribe to specific channels with arguments about what data they want (for example, scoping the data to a specific simulator). The publish function takes the provided data, filters it for the arguments supplied by the clients, and then sends the data to the clients over WebSockets. The clients then update based on the new data.

Here is a diagram depicting this process:

Thorium Data