Room Schema Docs Gradle Plugin

A Gradle plugin to automatically generate Entity-Relationship (ER) diagrams in Mermaid format from Android Room database schema JSON files.

Features

• Generates ER diagrams in Mermaid syntax based on Room schema JSON files.
• Outputs diagrams embedded in Markdown files, making it easy to review schema relationships and manage database changes over time.

Output Example

When schema JSON files like sample/schemas exist, you can generate Markdown(Mermaid Syntax) documents like sample/schemas-docs.

Getting Started

Prerequisites

• Android Room configured to export schemas.
• Gradle 7.x or higher.

Installation

1. Add the plugin to your build.gradle.kts:

plugins {
    id("jp.ntsk.room-schema-docs") version "1.1.0"
}

2. Ensure Room's schema export is enabled by adding the following to your build.gradle.kts:

room {
    schemaDirectory("$projectDir/schemas")
}

refs. https://developer.android.com/training/data-storage/room/migrating-db-versions#set_schema_location_using_room_gradle_plugin

3. Configure the plugin in your build.gradle.kts:

roomSchemaDocs {
    schemaDir = "$projectDir/schemas"
    outputDir = "$projectDir/schemas-docs"
}

Generating ER Diagrams

After setting up, run the following command to generate ER diagrams:

./gradlew generateRoomSchemaDocs

Output Example

For a directory structure like:

schemas/
├── <YOUR_PACKAGE_NAME>/
│   └── 1.json

The plugin will generate:

schemas-docs/
├── <YOUR_PACKAGE_NAME>/
│   └── 1.md