ScalaTags + htmx + ZIO HTTP Demo

This is a small demo project showcasing an integration between

• ZIO HTTP
• ScalaTags
• htmx

Welcome to Neon Pages: an extremely minimal CRM where you can keep a database of people with name, email, phone number or other data. You can add, remove, edit and search for people in the web app, and bulk-edit/bulk-delete.

This is a single-page application (SPA) built with ZIO, ScalaTags and htmx.

How to run

This demo project has a main class in Main.scala, so you can run the project by

sbt run

How to develop

Fork or clone this repo and in an SBT console do

~compile

and SBT will pick up your changes as you develop. The server will have to be restarted.

Structure

This application is built with

• a SQLite store, which can be replaced by Postgres or some other database
• Quill for type-safe queries
• ZIO for managing effects
• ZIO HTTP for server endpoints
• ScalaTags for server-side rendering (SSR)
• htmx, a JavaScript library which manages classic single-page application (SPA) flows and backend calls via custom HTML attributes

The "architecture" of the application is layered using ZLayers:

• in db we have layers for the Quill data sources
• repositories is layer for type-safe CRUD operations we're interested in, created with Quill, based on the db layer
• services is a layer dedicated to business logic, usually with one or more actions from repositories
• controllers is a layer for HTTP endpoints and request/response handling logic, usually delegating to one or more services
• on top of that, views is the Scala representation of the web pages (with ScalaTags and htmx attributes), which we serve directly

Besides the classical layers, we have a domain for the data types and errors we're using in the app, and a config layer which can fetch configuration from application.conf. The application also contains a Flyway service for migrations.