Workflows with XState

[FyreByrd]

Uses the XState library to create FSM instances that model the desired workflow behavior.

Features:

• Persistence: Each instance has an associated DB record (in WorkflowInstances) that stores enough information to restore to the current state.
• User Tasks: Each instance updates the UserTasks table with the appropriate information.
• Product Transitions: Each instance updates the ProductTransitions table with the appropriate information.
• Tasks: The appropriate actions are provided based on the user in the /tasks/[product_id] and are handled by the FSM.
• Admin: A barebones table of instances is provided in /admin/workflows.
  • Clicking on an entry will take a user to a visualization in /admin/workflows/[product_id]
  • While in the visualization, a user can select a state node and then press a button in a menu to jump the machine state to the selected state

Future Priorities:

• Hook actions into backend
• Authentication
• Republish and Rebuild workflows
• Workflow instance filtering/sorting in /admin/workflows
• Improve visualization (and visualization efficiency)

[7dev7urandom]

Looks pretty good; well done.

Here's a first-look review. I haven't reviewed the default-workflow.ts stuff at all, and I haven't tested anything, but here's some comments I have looking through it rather quickly. Some questions are probably somewhat ignorant because I'm not entirely clear what your goal is, but I think they'll be helpful.

One larger thing: you're handling the state machines with a lot of functional programming. You have a lot of functions that take WorkflowMachine or WorkflowContext as (often the first) argument, which makes me wonder if it could be done in a more object-oriented way, making things more intuitive to write.

[FyreByrd]

I have created a wrapper class for DefaultWorkflow and have updated all the rest of the code in accordance with that change.
I have also fixed a few small things that I noticed while working on that change (they are related to workflow, so still valid for the PR).

[7dev7urandom]

Wow, it does look a lot better and easier to use. Let me know what you think of my feedback.

[7dev7urandom]

Looks good to me, let's try it out!

[FyreByrd]

Switch to using svelte-kit superforms in a few pages

[chrisvire]

👍