Knowledge Graph

Introduction

The Knowledge Graph Module allows to build schemas from schema.org using the field ui. A schema can be used to map content type fields and properties as a schema property and output it as JSON-LD in the HTML head.

Requirements

* Entity API (https://www.drupal.org/project/entity)
* Chaos tool suite (ctools) (https://www.drupal.org/project/ctools)

Recommend Modules

* Field Group (https://www.drupal.org/project/field_group):
When enabled, you can add a group to direct fields (see below). May be required later.

Installation

* Install as you would normally install a contributed Drupal module. See:
https://drupal.org/documentation/install/modules-themes/modules-7
for further information.

Configuration

Creating a schema

This module provides the entity "Knowledge Graph Entity" which stores the mapping of one schema for one content type.
First, create a Knowledge Graph Type which is a bundle of the Knowledge Graph Entity. A Knowledge Graph Type represents
a schema from schema.org.

To create a Knowledge Graph Type, go to /admin/structure/knowledge_graph and add a knowledge graph type. Add new
fields using "Manage Fields".
This module provides a new field type "Knowledge Graph Mapper" which later will take
care of mapping values of a content type. When adding a field of this type, you can set "group" and "property" of this
mapping in the field settings of the instance. This should match with the schema definition on schema.org. If you want
this field to be rendered as "location.name", you have to set "location" as "group" and "name" as property.
(Note: This may change in the future if we decide to fully require the field group module.)
You can also add fields of different field types which will be rendered directly (called "Direct Fields" in this module).
A common practice would be to add a "@type" field which will declare the type of your mapping matching the type on
schema.org.
To render direct fields in groups in a schema, we currently require you to use the Field Group module. If you want to
add a "location.@type" field, you have to add a field group "group_location" and add a "@type" field in this group.
The module will then take the "location" out of "group_location" as group and the field label as property.

Map a content type

After creating a map, you should see a button "Add mapping" which will direct you to a page where you can define which
property of field value should be mapped on which field in the schema. You can select every column of every field.
Note: Entity Reference Fields are also supported up to the first level. If you want to get a value of a referenced entity,
you should see all values of the referenced entity available in the drop downs.

View the JSON-LD

After creating the map, you should see the JSON-LD output in the HTML head when viewing your node.

You can test your schema output on https://developers.google.com/structured-data/testing-tool/

Development

This module is still under development.

Example Feature

A simple schema for music events: https://github.com/Cyberschorsch/knowlede_graph_music_event

Maintainers

Current maintainers:
* Lucio Waßill (Cyberschorsch) https://www.drupal.org/u/cyberschorsch
* Steffen Rühlmann (SteffenR) https://www.drupal.org/u/steffenr

This project has been sponsored by:

* undpaul (http://wwww.undpaul.de)
* Warner Music Group Germany (http://www.warnermusic.de)