PDFlib TET PDF IFilter 4.0 Manual

3.4 Custom Metadata Properties
Custom metadata properties are additional properties beyond the predefined properties
which meet specific requirements within an enterprise, organization, industry etc.
TET PDF IFilter gives you full control over custom properties: they can be specified in
the configuration file so that they will be generated by TET PDF IFilter and indexed by
the search engine.
Planning custom metadata properties. In order to specify custom properties you
must consider the following aspects (see »Property identification and GUIDs«, page 40,
for details on GUIDs, identifiers, and friendly names):
> You can group one or more properties in a property set. Each property set needs a
unique 128-bit identifier called the GUID.
> The property identifier is a unique integer which identifies the property within its
property set. Property identifiers in a set start at the value 2. With some IFilter clients
the identifier can be replaced with a friendly name. You can override predefined
properties by assigning the corresponding GUID+ID combination.
> The friendly name for a property is optional if an identifier is available, and required
otherwise. It can be an arbitrary name which must be unique within the configuration
file. While for some IFilter clients it can be used instead of the identifier, friendly
names do not work with all IFilter clients.
> Property source: properties can be populated from document metadata or general
PDF information according to Section 3.1, »Sources of Metadata in PDF«, page 37.
> The data type of the property: Int32 (32-bit integer), Double (floating point number
with double precision), Boolean (true/false), DateTime (specification of a point in
time), and String.
> The precedence rule: if there is more than one data source for the property you can
specify whether the first available non-empty data source will have precedence (i.e.
subsequent sources will be ignored), or whether data from all non-empty sources
will be collected.
> Specify whether the property will be emitted as a vector, i.e. multiple values will be
handed to the IFilter interface in an array structure instead of a flat value (see Section
3.5, »Multivalued Properties«, page 44).
> A prefix which will be prepended to the property name if properties are indexed as
part of the full text (see Section 3.6, »Indexing Metadata Properties as Text«, page 45).
XML configuration for custom properties. One or more custom properties can be specified
in the PropertySet element, where each Property element describes a property in the
set:
Multiple PDF sources can be mapped to the same Windows property. The presence of a
Property element will automatically enable processing for the specified property. However,
handling of all predefined and custom metadata properties can be completely disabled
with the metadataHandling attribute of the Filtering element:
42 Chapter 3: Metadata Properties