Skip to content

Reading Values

In order to get an existing value, the HTTP method GET has to be used. The request has to be sent to the Knora server using the values path segment. Reading values may require authentication since some resources may have restricted viewing permissions.

Reading a Value

The representation of a value can be obtained by making a GET request providing the value's IRI:

HTTP GET to http://host/v1/values/valueIRI

In the response, the value's type and value are returned (see TypeScript interface valueResponse in module valueResponseFormats).

Getting a Value's Version History

In order to get the history of a value (its current and previous versions), the IRI of the resource it belongs to, the IRI of the property type that connects the resource to the value, and its current value IRI have to be submitted. Each of these elements is appended to the URL and separated by a slash. Please note that all of these have to be URL encoded.

Additionally to values, the path segment history has to be used:

HTTP GET to http://host/v1/values/history/resourceIRI/propertyTypeIRI/valueIRI

In the response, the value's versions returned (see TypeScript interface valueVersionsResponse in module valueResponseFormats).

Getting a Linking Value

In order to get information about a link between two resources, the path segment links has to be used. The IRI of the source object, the IRI of the property type linking the the two objects, and the IRI of the target object have to be provided in the URL separated by slashes. Each of these has to be URL encoded.

HTTP GET to http://host/links/sourceObjectIRI/linkingPropertyIRI/targetObjectIRI

In the response, information about the link is returned such as a reference count indicating how many links of the specified direction (source to target) and type (property) between the two objects exist (see TypeScript interface linkResponse in module valueResponseFormats).

Last update: 2023-06-01