What are Metadata Forms and Groups?

Forms describe a set of fields, including their type and how to extract them from the metadata, but leaving the details of how to display the fields up to the consuming application (e.g. NGI). Several commonly used schemas already have forms created by Preservica, and new ones can be added through the API.

The swagger documentation for both is available at Metadata API documentation

Groups (and Forms for Groups) can also be created and edited in NGI.

What are forms and how do I create one for my schema?

Each form defines:

• title
• description
• schemaUri - the schema it applies to
• default - which form should be used by default for said schema (e.g. NGI displays metadata using the default and offers the user the option to switch to alternative forms)
• fields - a list of fields

Each field defines:

• path - the xpath to extract the value from the metadata (//ns: is the default namespace for the schema)
• label
• type - what sort of data is in this field, can be String, LongString, Date or Number.
• visible (optional, default true) - whether the field should be displayed when viewing metadata using this form
• editable (optional, default true) - whether the field can be edited
• maxOccurs (optional) - how many of this field are allowed
• allowableValues (optional) - a restricted list of values that this can be set to
  • values - a list defined directly in the form
  • referenceMetadata - a list pulled from reference metadata if applicable (should take precedence over values)

Examples

Say I have some metadata that I want to be able to view and edit

The following form would enable this:

This has the bare minimum, relying on defaults for the unspecified fields.

The following example is a slightly more customized form, which limits the maximum number of each field to 1 and sets allowable values.

And finally, this is the the response to getting the form above when reference metadata has been setup against the Name field.

Group Details

Each Group defines:

• name (from which the schema uri is generated)
• description
• fields

Each field defines:

• id
• name - used as form label
• type - what sort of data is in this field and how should it be indexed, can be STRING, LONGSTRING, DATE or NUMBER.
• maxLength (optional)
• defaultValue (optional) - used for the template
• visible (optional, default true)
• editable (optional, default true)
• minOccurs
• maxOccurs
• values (optional) - used for form allowableValues.values
• indexed (optional, default false) - whether the field should be individually indexed so can be filtered on

Example

Here is a small group that would create a form matching that described above