HoloREA

A modular REA implementation for Holochain

• Setup
  • Prerequisites
  • Initialising for development
• Dev mode
  • Service entrypoints
• Useful development tools
• Project structure

Setup

Prerequisites

The simplest setup is with Yarn, Docker and Docker Compose.

• Install latest versions of Docker & Docker Compose from their respective websites.
• If you don't have Yarn- npm i -g yarn using the version of node you plan on developing this project against (for recommended, see .nvmrc). You can setup your modules manually using npm link if you prefer, but Yarn's workspaces feature will save you a lot of time.

If you wish to proceed with setting up a local Go toolchain and running hcdev locally, feel free to add instructions on this method here.

Initialising for development

• Run yarn install from the root of this repo. This will setup all necessary node_modules folders and symlinks between repositories kept in this package which depend on each other.

Dev mode

• npm start gets you both a webserver pointing to src/ui and a Holochain 0.0.1 Prototype DHT running for your backend. If you wish to run these commands separately (useful when troubleshooting the DHT code), see the scripts in package.json prefixed with dev:.

PLEASE NOTE: you will see the error "TypeScript emitted no output for [...]" when running the frontend. This issue appears to be intermittent. If you simply open the source file experiencing the issue in your editor and re-save it, compilation appears to succeed in subsequent rounds.

Service entrypoints

When running in development mode, these are the components which will be booted up & where to find them:

• Our demo UI at http://localhost:3000
• A GraphQL query browser at http://localhost:3000/graphql
• A test REPL for the Holochain app at http://localhost:3141
• The Holochain app Zome APIs at subpaths of http://localhost:3141/fn/*

Useful development tools

1. Apollo Client Developer Tools

For assisting with writing and debugging GraphQL queries.

2. Redux Devtools Extension

For assisting with debugging application state- both the Apollo cache and other UI state.

• Chrome:
  • Click on the Redux devtools icon in your toolbar
  • Click the 'remote' button in the bottom right, which should pop up a screen
  • Navigate to "settings", enable "Use custom (local) server", set to localhost, port 7999
• Firefox:
  • If you see an empty screen with an error when opening the devtools panel, you will need to navigate to a Redux app (like this one) to get it to load, after which you can...
  • Click the 'remote' button in the bottom right, which should pop up a screen (Firefox seems to currently be broken here, you'll probably have to use Chrome)
  • Navigate to "settings", enable "Use custom (local) server", set to localhost, port 7999
• VSCode: check out vscode-redux-devtools.

Note there are some platform-specific quirks, and you may be forced to use the Chrome version as the Firefox extension has some bugs.

Project structure

• /bin: output files from the TypeScript compilation of the source DHT code kept in src/HoloREA/dna
• /build: shell commands used to build the DHT code and setup the repo
• /docs: more in-depth documentation files to understand particular areas of the app
• /src/graphql-adapter: a REA-flavoured, client-side GraphQL adapter for the 0.0.1 Holochain zome REST APIs, used by the frontend app
• /src/HoloREA: the Holochain app DHT code
• /src/lib: helper files used in DHT code
• /src/tests: Holochain app unit tests & demonstration scenarios
• /src/ui: Example frontend app which talks to the DHT
• /src/ui/config: Webpack configuration files for frontend app
• /src/ui/scripts: shell commands for running development tasks
• /src/ui/public: directory to serve alongside bundled JS files, incl. webpage template
• /src/ui/src: bulk of the frontend app code