GAEB4Linux

GAEB4Linux is an open-source GAEB viewer and editor designed for Linux systems. GAEB XML is a standardized data exchange format used extensively in the German construction industry for specifications, pricing, quantity takeoffs, invoicing, and calculations.

The project aims to provide a free, open-source alternative to the proprietary software currently dominating this field, with a modern and modular architecture based on Java and Vaadin. 🎯 Project Goals

Enable Linux users to work with GAEB XML files.
Support standard formats (X81–X87) used for tender specifications.
Provide a modern, web-based user interface.
Maintain an open-source and extensible architecture.

🧠 Architectural Approach: Hybrid Storage Model

GAEB4Linux uses a hybrid database architecture to leverage the strengths of both XML-native and relational data models: XML Database (BaseX or eXist-db)

Stores GAEB XML files in their original structure.
Ideal for executing complex XQuery/XPath operations.
Maintains full fidelity of the GAEB format.

Relational Database (PostgreSQL)

Manages project metadata, users, roles, and transactional data.
Suitable for multi-user environments, project tracking, invoicing, and master data (e.g., materials, personnel).
Ensures consistency and reliability with ACID compliance.

Integration Strategy

Projects reference GAEB XML files via URI or unique IDs.
The backend synchronizes business logic between both data sources.
This design ensures scalability, fast query performance for structured data, and flexibility for XML-based processing.

Result: A robust, scalable system combining the semantic richness of XML with the structural integrity of relational databases. 🧩 Planned Features Step 1 – GAEB Viewer

Load and display GAEB files (X81–X87).
Import/export to and from all GAEB XML formats.
Edit prices, text additions, and bidder details.
Show/hide XML tags.
Export complete tender documents as PDF, including headers and footers.

Step 2 – Create Tender Specifications

Create new tender documents.
Import texts or select from templates.
Optional connection to standard service catalogs or text-generation features.
Basic project management integration.
XML database support for data persistence.

Future Modules

Request and offer management.
Price calculation module.
Quantity determination module.
Invoicing module.
Master data management (equipment, personnel, materials, subcontractors).
Interfaces to third-party construction software.

⚙️ Features

Load and parse GAEB XML files
Display GAEB structures in a Vaadin-based web interface
Communicate with an XML database (BaseX or eXist-db) via REST
Modular code structure designed for collaboration
Licensed under the Mozilla Public License 2.0 (MPL 2.0)

🧪 Technologies Used Component Technology Programming Java 21 Web UI Vaadin Flow Database BaseX or eXist-db + PostgreSQL Query Language XQuery Build Tool Maven License MPL 2.0 🗂️ Project Structure

gaeb-viewer/ ├── gaeb-core/ # Java logic for GAEB parsing and domain model ├── gaeb-webui/ # Vaadin-based web application (frontend) ├── gaeb-xml-db-server/ # REST-based XML database API (BaseX or eXist-db) ├── pom.xml # Maven parent configuration └── README.md # You are here

🚀 Getting Started Requirements

Java 21
Maven 3.8+
PostgreSQL 14+ (for structured project/user data)
BaseX 10.7+ or eXist-db 6+ (for GAEB XML files)

Setup Instructions

Before running the application, ensure that both your PostgreSQL and XML database servers are installed and running. PostgreSQL is used for project metadata and user management, while GAEB XML files are stored in the XML database.

Clone the repository

git clone https://github.com/yourname/gaeb-viewer.git cd gaeb-viewer

Start your PostgreSQL server

(Make sure to create the database and schema using available SQL scripts)

Start your XML database (BaseX or eXist-db)

Deploy XQuery endpoints to your XML DB

cp gaeb-basex-server/webapp/restxq/ <your database's REST folder>

Run the web application

cd gaeb-webui mvn spring-boot:run

🤝 Contributing

Contributions are welcome! Feel free to fork the repository, open issues, or submit pull requests. The goal is to develop a collaborative platform for open GAEB tools. 🪪 License

This project is licensed under the Mozilla Public License 2.0 (MPL 2.0).

To ensure license compatibility, all XML databases are accessed via REST to avoid linking with GPL-licensed code like BaseX directly. You may use eXist-db as an alternative.