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Write a technology adapter

Introduction to TAs​

A Resource is an external source of information, such as a file, a database, or a server. It is managed by OpenFlexo but does not store data internally. Rather, it provides access to the data through a structured interface.

A ModelSlot bridges the gap between a Resource and the OpenFlexo modeling framework (specifically, FML Flexo Modeling Language). Depending on how we want to interact with a Resource, different types of ModelSlots may be available for the same Resource type.

In that context, a Technology Adapter (TA) is defined for a Resource type and offers various ModelSlots to interact with that Resource type.

A ResourceData represents the content of a Resource as interpreted by OpenFlexo when structured according to an external meta-model, which defines its format and constraints. Some external meta-models are defined as annotated Java APIs that can be used as types in FML, while others may exist in external formats (e.g., XML Schemas, JSON Schemas).

The three main types of ModelSlots:​

  • Free ModelSlot – Directly links a Resource to its ResourceData based on an external meta-model defined as a Java API. The structure and constraints of the data are dictated by the Java API, which serves as the meta-model.

  • Type-Aware ModelSlot – Links a Resource to its ResourceData based on an external meta-model defined in a non-Java format (e.g., XML Schema, JSON Schema). The ModelSlot interprets the external schema to enforce structure and constraints.

  • Reflected ModelSlot – Links a Resource directly to a VirtualModelInstance, where an FML-based representation (instead of an external meta-model) defines how the data is structured and manipulated within OpenFlexo.

Getting started​

Every technology adapter follows the same fixed multi-module template — the xx-ta skeleton — and a new one is scaffolded and wired end to end with the add-technology-adapter guided procedure rather than by hand. A worked walkthrough (basic structure, examples, testing, common pitfalls) covering one TA built from scratch is not written yet.