Namespaces and Extensions
An introduction to "@context" URLs and field names, namespaces (their evolution and deprecation), and extensions.
Last updated
An introduction to "@context" URLs and field names, namespaces (their evolution and deprecation), and extensions.
Last updated
In the world of linked data on the web, "namespaces" ("@context") are a collection of "properties" (fields) that have a well defined meaning.
Within the imin data, there are five primary namespaces used, all which are listed in the table below. You can click on each of the namespaces below to see a list of the properties contained within.
imin data is valid JSON-LD, which means that properties will always exist in one of the specified namespaces ("@context").
Namespace
Prefix
Context URL
Bundles
Prefix Required
Status
Deprecation Policy
-
https://schema.org/
No
Living Standard
-
http://www.w3.org/2004/02/skos/core#
No
Stable
-
https://openactive.io/
schema.org, SKOS
No
Stable
Yes
imin:
https://imin.co/
Yes
Stable
Yes
beta:
https://openactive.io/ns-beta
Yes
Experimental
*
*
Yes
Experimental
The includes a "profile" (subset) of schema.org and SKOS, which has been defined for OpenActive use, along with the specification for OpenActive namespace.
Please note that properties defined outside of the and namespaces are not subject to the imin deprecation policy and are subject to change at any time. Therefore, we strongly encourage a approach.
However, if you are considering one of these fields to drive critical production functionality, please get in touch with us at and we will work with you to propose your use case to the and move the field into either the OpenActive or imin namespace.
When reading a response which contains JSON-LD, you'll should refer to the "@context" property, which is designed to let you know which namespaces are in use.
Three key things to remember:
The OpenActive namespace also bundles SKOS and schema.org namespaces inside it:
So writing
"@context": [ "https://openactive.io/" ]
is the same as writing
"@context": [ "https://openactive.io/", "https://schema.org/", "http://www.w3.org/2004/02/skos/core#" ]
OpenActive, SKOS and schema.org namespaces do not require a prefix when using them:
So you must write "name": "Tai chi Class" instead of "schema:name": "Tai chi Class"
All other properties always require a prefix:
You must write "imin:fullAddress" and never "fullAddress"
This example references the namespaces of OpenActive (as noted above, this automatically includes schema.org and SKOS) and imin.
The OpenActive W3C Community Group and imin both contribute to discussions within schema.org, however, consensus involves a number of stakeholders and can be time consuming to reach.
This specification is not expected to be updated, however, the use of the specification within OpenActive is subject to change in line with the OpenActive versioning policy.
Data consumers should not assume that properties in the OpenActive Beta namespace will either be added to the core specification or be included in the namespace over the long term.
imin data sometimes contains additional namespaces, known as extensions. Data publishers may use these extensions to include additional fields that are not currently being considered as part of the evolving OpenActive standards.
In this example, the "britishcycling:gpxFile" field is defined by an extension provided by British Cycling, using their custom namespace "http://data.goskyride.com/opendata/britishcycling.jsonld".
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is a collaborative, community activity with a mission to create, maintain and promote schemas for structured data on the Internet; on web pages, in email messages and beyond. It was founded by Google, Microsoft, Yahoo and Yandex.
The terms of schema.org continue to evolve through lively discussions on their and . Often properties are added for some specific use case and their potential relationship to other areas of schema.org only becomes clear later. This gives rise to changes in textual definition and property-to-type associations that gradually make schema.org more coherent, without introducing radical changes in meaning. Consumers of schema.org data can generally rely on schema.org term meanings not changing dramatically. However, term definitions often evolve gradually over time to accommodate new usage scenarios or to improve usability. When schema.org properties are occasionally deprecated, they stay in the namespace so that they can still be used and are simply referenced to their replacement property.
Where a schema.org property is explicitly included in the , it follows the OpenActive versioning policy. Where a schema.org property is not included in the OpenActive Modelling Specification, its usage may be subject to change. However, due to schema.org's internal processes and policies, it is highly unlikely to change in name, but somewhat more likely to subtly change in definition.
The , published in 2009, is centred around the Concept type and provides a mechanism for organising these concepts into a hierarchy. It is used for the and other controlled vocabularies where an enumeration of specific terms are defined.
The was established with the objective of facilitating the sharing and use of physical activity data. We very much encourage you to join the conversation and help shape the standards and our future API iterations through this process.
The defines a subset ("profile") of schema.org and SKOS that has been defined for OpenActive use, along with additional properties that feature in the OpenActive namespace.
Descriptions and examples of the , including the defined subset ("profile") of schema.org and SKOS, together with all properties from the OpenActive namespace, are included in the .
The within that specification specifies the use of version numbering to indicate potential for breaking changes: minor versions, e.g. 1.1, 1.2, etc. should be backwards compatible; major versions, e.g. 2.0, 3.0 are likely to include breaking changes. It is estimated that such breaking major version releases will only occur at most annually. imin will strive to align major version releases with OpenActive major version releases, with any deprecated imin API major version maintained for a period in accordance with the imin deprecation policy.
The properties defined in the are subject to the imin deprecation policy.
The is maintained to facilitate the early stabilisation of properties ahead of their broader adoption and standardisation. imin works as part of the to promote the use cases represented by the properties within this namespace, with the intention of standardising them into the over time (where applicable).
When a property "graduates" from the imin namespace into the , it will be maintained as a duplicate property for 12 months and deprecated in accordance with the imin deprecation policy.
The namespace provides a custom namespace that can be used by publishers experimenting with new properties that are likely to be added to the core specification. It is defined as a convenience to help document properties that are in active testing and review by the community.
Please note that OpenActive Beta namespace properties are not subject to the imin deprecation policy and are subject to change at any time. Therefore, we strongly encourage a approach. However, if you are considering one of these fields to drive critical production functionality, please get in touch with us at and we will work with you to propose your use case to the and move the field into either the OpenActive or imin namespace.
Please note that extension properties are not subject to the imin deprecation policy and are subject to change at any time. Therefore, we strongly encourage a approach. However, if you are considering one of these fields to drive critical production functionality, please get in touch with us at and we will work with you to propose your use case to the and move the field into either the OpenActive or imin namespace.