Experience Data Model (XDM) Schema

The Experience Data Model (XDM) is the language of digital experiences. XDM is a publicly documented specification, driven by Adobe to improve the interoperability, expressiveness, and power of digital experiences. This repository contains the source code for the formal specification of the XDM model, using the JSON Schema language.

Current Version

XDM is at version 0.9. You can find more about our versioning in docs/introduction.md

Read the XDM Spec

• Chapter 1: Introduction
• Chapter 2: Related Standards
• Chapter 3: Terminology
• Chapter 4: Extending XDM
• Appendix A: Reference – this contains all the schemas defined by XDM

Project Layout

The project is laid out in the following way:

• docs: Markdown files that contain front-matter, introduction, and non-normative parts of XDM
• schemas: JSON schema files constituting the normative part of XDM
  • *.schema.json is the schema file, e.g. event-envelope.schema.json – we pick the .json file extension for easy syntax highlighting in editors
  • *.example.*.json is an example file that will be validated against the *.schema.json file, and if successful, merged into the *.schema.json file as an "example" field at the root of the schema before it is converted into Markdown or published
  • *.invalid.*.json is an invalid example file that will be validated against the *.schema.json file. If the invalid file validates (false positive), the schema is too lax and the overall build will fail. invalid files will not be merged into documentation.
  • *.description.md is a description file that will be merged into the "description" field at the root of the schema, allowing the authoring of longer descriptions. The merge happens before publishing the schema file or creating a joint Markdown file
  • schemas/assets – for schemas related to the asset core concept, including image, video, document
  • schemas/audiences – for schemas describing audiences, segments, and groups of consumers
  • schemas/campaigns – for schemas describing orchestrated experience campaign
  • schemas/content – for schemas related to content, including visual, audible, and virtual reality content
  • schemas/context – for schemas related to the context of a digital experience, including profile, person, environment
  • schemas/data – for schemas describing collected data, metric, etc.
  • schemas/external/* – for JSON Schema representation of externally defined standards
  • schemas/channels – for schemas describing experience channels and locations therein
  • schemas/common – for basic concepts like extensibility that are not covered in external schemas
• *.ttl: legacy schema files in Turtle Syntax that have not yet been converted into JSON Schema
• package.json: a build file for npm that allows the generation of Markdown from the JSON Schema source files and (later) the generation of an AEM package to be deployed on the Adobe I/O Website
• README.md: this file
• CONTRIBUTING.md: guidelines for contributors, covering process, conventions and design guidelines

Tooling

The tooling project (e.g. for generating Markdown documentation, example validation, JSON Schema documentation inlining) is located in the adobe/jsonschema2md git repository.

Dependencies

You need:

1. Node.js and npm
2. curl

Validation of local changes prior to creating any Pull Requests to adobe/xdm

This project contains a minimal validation script that depends on NPM. You can use it to validate the JSON example files against the JSON Schema files after making changes to either.

From the root directory of the local repository run:

$ npm install
$ npm test

> xdm-models@0.0.1 test /Users/lars/Code/models
> sh validate.sh

Validating schemas/common/eventenvelope.example.1.json against schemas/common/eventenvelope.schema.json
schemas/common/eventenvelope.example.1.json valid
Validating schemas/common/eventenvelope.example.2.json against schemas/common/eventenvelope.schema.json
schemas/common/eventenvelope.example.2.json valid
Validating schemas/common/eventenvelope.example.3.json against schemas/common/eventenvelope.schema.json
schemas/common/eventenvelope.example.3.json valid
Validating schemas/common/eventenvelope.example.4.json against schemas/common/eventenvelope.schema.json
schemas/common/eventenvelope.example.4.json valid
Validating schemas/common/eventenvelope.example.5.json against schemas/common/eventenvelope.schema.json
schemas/common/eventenvelope.example.5.json valid

If you see warnings or error messages (or an non-zero exit code), fix them before making a pull request.

Naming Conventions

• see the Contributor's guide

AEM Package Generation (optional)

With all dependencies installed, run the following commands from the root directory of the local repository:

$ npm install
$ npm run package

This will fetch all dependencies, then generate Markdown in the docs/reference directory and then generate an AEM package under xdm-docs.zip. The package can be uploaded using the command

$ npm run upload

upload will upload to the Adobe I/O Staging instance. To upload to production, use upload:prod instead.

The AEM password is not saved in this repository (of course), but you can set it using this command:

$ npm config set xdm-models:aem_password $AEM_PASSWORD

This is assuming $AEM_PASSWORD has been provided to your Continuous Integration system or set on the command line beforehand.

Running upload will only make the documentation visible on the "author" instance, this means visitors to the site cannot see any of the documentation. To publish it, run the npm run activate or npm run activate:prod commands.

A full process would then look like this:

$ npm config set xdm-models:aem_password $AEM_PASSWORD
$ npm install
$ npm test
$ npm run package
$ npm run upload
$ npm run activate

This will generate documentation, create an AEM package, install it on (stage) author, and activate it from there, so that visitors can read the documentation.

A Note on Dependencies

The package.json script will fetch a released version of the AEM Markdown Importer JAR using curl.

Links

Specifications

• JSON Schema
• JSON-LD 1.0
• XMP SPECIFICATION PART 1 DATA MODEL, SERIALIZATION, AND CORE PROPERTIES

Vocabularies/Ontologies

• schema.org
• Dublin Core
• OWL
• SKOS Core

License/Copyright

Copyright 2017 Adobe Systems Incorporated. All rights reserved. This work is licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) license.

You are free to:

• Share — copy and redistribute the material in any medium or format
• Adapt — remix, transform, and build upon the material for any purpose, even commercially.

This license is acceptable for Free Cultural Works.

The licensor cannot revoke these freedoms as long as you follow the license terms.

Under the following terms:

• Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
• No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.