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Changing a Value

To add values to an existing resource, the HTTP method PUT has to be used. Changing values requires authentication since only known users may change values.

Modifying a Property Value

The request has to be sent to the Knora server using the values path segment followed by the value's IRI:

HTTP PUT to http://host/values/valueIRI

The value IRI has to be URL-encoded.

To change an existing value (creating a new version of it), the value's current IRI and its new value have to be submitted as JSON in the HTTP body.

Depending on the type of the new value, one of the following formats has to be used in order to create a new value (all these TypeScript interfaces are defined in module changeValueFormats):

  • changeRichtextValueRequest
  • changeLinkValueRequest
  • changeIntegerValueRequest
  • changeDecimalValueRequest
  • changeBooleanValueRequest
  • changeUriValueRequest
  • changeDateValueRequest
  • changeColorValueRequest
  • changeGeometryValueRequest
  • changeHierarchicalListValueRequest
  • changeIntervalValueRequest
  • changeGeonameValueRequest

Modifying a File Value

To change a file value, the client first uploads the new file to Sipi, following the procedure described in Adding Resources with Image Files.

Then the client sends a request to Knora, using this following route:

HTTP PUT to http://host/filevalue/resourceIRI

Here, resourceIRI is the URL-encoded IRI of the resource whose file value is to be changed. The body of the request is a JSON object described in the TypeScript interface changeFileValueRequest in module changeValueFormats, and contains file, whose value is the internalFilename that Sipi returned. The request header's content type must be set to application/json.

Response on Value Change

When a value has been successfully changed, Knora sends back a JSON with the new value's IRI. The value IRI identifies the value and can be used to perform future DSP-API V1 operations.

The JSON format of the response is described in the TypeScript interface changeValueResponse in module changeValueFormats.

Last update: January 19, 2023