erm-vsc

A VS Code extension for ER diagrams — an ERMaster replacement with full compatibility with the .erm format: files open and save so that the original Eclipse ERMaster plugin still reads them (and vice versa).

Features

• Visual .erm editor (custom editor, SVG canvas)
  • tool palette (Select / Table / Note / Relation)
  • ERMaster-style tables: colored header, primary keys on top with a separator, PK/FK markers
  • relations in IE (crow's foot) notation, auto-created FK columns
  • categories (visual grouping frames), notes, colors
  • display modes: logical / physical / both
  • edit dialogs on double-click; context menu; zoom/pan
• ERMaster compatibility — the native XML format is implemented: word dictionary, relations with cardinalities, indexes (including the historical <inidex> typo), categories, test data, change tracking and settings all survive a round-trip losslessly; cross-references are renumbered exactly like PersistentXmlImpl
• DDL generation — PostgreSQL and MySQL (tables, PK, FK, UNIQUE, indexes, comments, sequences, views)
• DDL import — turn a .sql file into a diagram
• Image export — SVG and PNG
• Validation — duplicate/empty names, missing PK, missing type reported in the Problems panel

Usage

• Open any .erm file — it opens as a diagram (right-click → Open With → Text Editor for the raw XML)
• ERD: New Diagram — create a new file
• ERD: Generate DDL — DDL toolbar button or right-click a .erm in the explorer
• ERD: Import DDL (.sql) as Diagram — right-click a .sql file

Development

npm install
npm run compile     # or npm run watch
npm run typecheck
npm test

Press F5 to launch the Extension Host, then open examples/shop.erm.

Build and install locally: npx @vscode/vsce package && code --install-extension erm-vsc-0.1.0.vsix

Structure

• src/erm/xml.ts — XML parser + escaping matching ERMaster exactly
• src/erm/model.ts — diagram model (raw values + object references)
• src/erm/load.ts — XML → model (mirror of XMLLoader.java)
• src/erm/write.ts — model → XML (mirror of PersistentXmlImpl.java, byte-for-byte)
• src/erm/ops.ts — editing operations (ERMaster command semantics)
• src/erm/validate.ts — model validation
• src/erm/importDdl.ts — DDL → diagram import
• src/ddl.ts — DDL generation
• src/erdEditorProvider.ts — custom editor (webview ↔ document)
• src/webview/ — the diagram editor (rendering, dialogs, tools)
• FEATURES.md — full list of ERMaster features and porting status