Access Metadata Fields
This section explains how to process metadata fields using the KeyView API.
Standardized Fields
When KeyView understands the meaning of a metadata field in a document, it outputs that data in a standardized field. Standardized fields are represented as MetadataElement
objects where:
-
the
standard_key
attribute contains the standardized field key, which indicates the meaning of the field. For a full list of standardized keys, refer to theMetadataKey
enumeration or see Standardized Metadata Fields. The standard key will not be equal toMetadataKey.Other
because this would indicate a non-standardized field. -
the
key
attribute contains a string that is uniquely determined by the standard field key. If you are handling the value of a standardized field based on its standardized name, you can ignore this value. It is provided so that standardized fields can optionally be handled in the same way as non-standardized fields.
Each standardized field is guaranteed to occur at most once in the metadata output. For example, a Metadata
object will contain zero or one MetadataElement
objects with the standard key MetadataKey.Title
.
Non-standardized fields
Non-standardized fields include user created fields, or fields that are specific to one file format. Non-standard fields are represented as MetadataElement
objects where:
- the
standard_key
attribute is equal toMetadataKey.Other
to signify that it is a non-standardized field. - the
key
attribute contains a string representation of a field's key. If a field key exists in the document, that value is returned. Otherwise, KeyView generates a value to describe the field.