Expressir Tutorials

Purpose

These hands-on tutorials guide you through common Expressir tasks from beginner to advanced topics. Each tutorial includes working code examples, practical exercises, and clear learning objectives.

Getting Started

If you’re new to Expressir, start with these foundational tutorials:

  1. Parsing Your First Schema - Learn the basics of parsing EXPRESS files

  2. Working with Multiple Schemas - Handle dependencies and interfaces

  3. Creating LER Packages - Package schemas for distribution

Tutorial Path

Follow this recommended learning path:

Beginner Level

Parsing Your First Schema

Duration: 30-45 minutes

Learn to parse EXPRESS schemas with both CLI and Ruby API, explore the parsed data model, and handle errors gracefully.

Working with Multiple Schemas

Duration: 45-60 minutes

Master schema dependencies, interfaces (USE FROM / REFERENCE FROM), and cross-schema reference resolution.

Intermediate Level

Creating LER Packages

Duration: 45-60 minutes

Create distributable LER packages for instant loading and high-performance schema distribution.

Querying Schemas

Duration: 60-75 minutes

Use the SearchEngine API for pattern matching, filtering, and complex queries across schemas.

Advanced Level

Liquid Templates

Duration: 60-90 minutes

Generate documentation automatically using Liquid templates and Expressir’s drop objects.

Documentation Coverage

Duration: 45-60 minutes

Analyze and improve schema documentation quality with coverage tools and metrics.

Tutorial Features

Each tutorial includes:

Prerequisites

What you need to know before starting

Learning Objectives

What you’ll be able to do after completion

Step-by-Step Instructions

Clear, numbered steps with explanations

Working Code Examples

Complete, tested code you can run immediately

Expected Output

What success looks like at each step

Practice Exercises

Hands-on activities to reinforce learning

Common Pitfalls

Mistakes to avoid and how to fix them

Next Steps

Where to go after completing the tutorial

Quick Reference

Tutorial Level Focus Duration

Parsing Your First Schema

Beginner

Parsing basics, CLI, Ruby API

30-45 min

Working with Multiple Schemas

Beginner

Dependencies, interfaces

45-60 min

Creating LER Packages

Intermediate

Packaging, distribution

45-60 min

Querying Schemas

Intermediate

SearchEngine, queries

60-75 min

Liquid Templates

Advanced

Documentation generation

60-90 min

Documentation Coverage

Advanced

Coverage analysis

45-60 min

Additional Resources

Before Starting

While Learning

After Completion

Tutorial Conventions

Code Blocks

EXPRESS code:

SCHEMA example;
  ENTITY person;
    name : STRING;
  END_ENTITY;
END_SCHEMA;

Ruby code:

require 'expressir'
repo = Expressir::Express::Parser.from_file('schema.exp')

Shell commands:

expressir format schema.exp

Callouts and Annotations

  • ✅ Success indicators

  • ❌ Error indicators

  • 💡 Tips and best practices

  • ⚠️ Important warnings

File References

File paths are shown relative to your working directory: * schema.exp - File in current directory * schemas/base.exp - File in subdirectory * /full/path/to/file.exp - Absolute path (rare)

Getting Help

Issues During Tutorials

  • Check the "Common Pitfalls" section

  • Verify prerequisites are met

  • Ensure file paths are correct

  • Check Ruby and Expressir versions

Questions or Problems
Contributing

Found an error or want to improve a tutorial?

  • Open an issue on GitHub

  • Submit a pull request

  • Share your feedback

Tutorial Versions

These tutorials are written for:

  • Expressir: v1.0+

  • Ruby: 2.7+

  • EXPRESS: ISO 10303-11:2007

If you’re using different versions, some examples may need adjustment.

Next Steps

Ready to start? Begin with Parsing Your First Schema or choose any tutorial based on your needs.

For quick reference without step-by-step instructions, see the Guides section.