BoxLang Desktop Runtime (Electron + MiniServer)

Overview

This skill applies to desktop applications that embed BoxLang using Electron and run a local BoxLang MiniServer process.

Core model:

• Electron owns desktop lifecycle (window, tray, menu, shortcuts).
• A local MiniServer process serves the BoxLang app.
• The BrowserWindow loads the local MiniServer URL.
• Frontend assets are served via Vite in development and built artifacts in production.

This pattern gives a desktop UX without replacing BoxLang with another backend stack.

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Architecture Baseline

Expected module boundaries:

• app/electron/Main.js: app bootstrap and module wiring.
• app/electron/BoxLang.js: MiniServer process manager (start/stop/restart/readiness).
• app/electron/AppMenu.js: application menu.
• app/electron/TrayMenu.js: tray behavior and status.
• app/electron/Shortcuts.js: global keyboard shortcuts.
• runtime/Package.bx: MiniServer runtime packager using .bvmrc.
• miniserver.json: local server runtime controls.
• .boxlang-dev.json: development BoxLang runtime defaults.
• .boxlang.json: production BoxLang runtime defaults.

Preserve modular boundaries in app/electron/* instead of collapsing logic into a single file.

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Packaging Model

Package the MiniServer runtime, not Java:

• Packaged runtime paths:
  • runtime/bin
  • runtime/lib
• Version source: .bvmrc
• Packager script: runtime/Package.bx
• Startup preference: packaged runtime/bin/boxlang-miniserver first, global boxlang-miniserver fallback.

Important runtime constraint:

• Java 21+ must exist on every machine running the desktop app.
• Only MiniServer binaries/libs are packaged, not a JRE/JDK.

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Configuration Responsibilities

miniserver.json (development server control)

Use this as the primary local server control file for desktop development:

• host/port binding
• webRoot
• rewrites
• debug
• envFile
• serverHome

Example:

{
    "port": 59700,
    "host": "127.0.0.1",
    "webRoot": "public",
    "serverHome": ".boxlang",
    "rewrites": true,
    "debug": false,
    "envFile": ".env"
}

.boxlang-dev.json vs .boxlang.json

Use split runtime config for predictable behavior:

• .boxlang-dev.json: development-focused runtime behavior (debugMode, cache toggles, testing mappings).
• .boxlang.json: production defaults for packaged desktop execution.

Both should include baseline mappings so classes/templates resolve predictably:

"/app": {
    "path": "${user-dir}/app",
    "external": false
},
"/public": "${user-dir}/public"

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Startup and Readiness Pattern

Recommended process flow in BoxLang.js:

1. Detect packaged runtime executable and fallback command.
2. Ensure execute permission on Unix-like systems.
3. Spawn MiniServer with miniserver.json.
4. Poll server URL readiness with timeout and retry interval.
5. On ready: load BrowserWindow URL.
6. On crash: apply controlled restart strategy with delay and user notification.

Checklist for robust lifecycle handling:

• startup timeout with clear error dialog
• readiness probe over HTTP before loading app URL
• restart suppression on intentional shutdown
• graceful stop on app quit/SIGINT/SIGTERM
• per-platform executable permission handling

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Build and Packaging Workflow

Common script set for this runtime style:

• npm run dev: Vite + Electron development loop.
• npm run build: build frontend assets to public/includes/resources.
• npm run package:miniserver: download/extract runtime from .bvmrc.
• npm run package: build assets and package desktop app.
• npm run package:full: package MiniServer, then package app.

Use package:full for distributable builds.

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BoxLang and Runtime Rules

• Use tag-based component syntax (bx:http {}, bx:zip {}), never new bx:....
• For CLI scripts (such as runtime packaging), parse args with CliGetArgs().
• Use expandPath() and check file/directory existence before destructive operations.
• Keep path construction cross-platform in Electron with path.join().

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Troubleshooting Guide

MiniServer fails to start

• Confirm runtime/bin and runtime/lib exist (run npm run package:miniserver).
• If using fallback mode, verify boxlang-miniserver is on PATH.
• Validate miniserver.json host/port/webRoot values.

Permission denied on Unix-like hosts

• Repackage with force: npm run package:miniserver:force.
• Verify executable bit on runtime/bin/boxlang-miniserver.

App runs but UI assets missing

• Run npm run build and confirm manifest exists in public/includes/resources/.vite/manifest.json.

Runs on dev machine but fails on user machine

• Confirm Java 21+ is installed on target machine.
• Remember: MiniServer is bundled, JRE is not.

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Best Practices

• Keep desktop, runtime, and web concerns separated by module.
• Treat miniserver.json as developer-facing runtime control.
• Keep both .boxlang-dev.json and .boxlang.json under source control.
• Keep /app and /public mappings stable unless there is a deliberate architecture change.
• Preserve packaged runtime fallback logic unless explicitly removing it.