Spotlight Importer Schema Format

For Spotlight to know what attributes an importer supports, it must provide a schema file. The schema file describes the attributes that the importer populates, describes the attributes that applications should use to provide a preview of the document’s metadata, and specifies any custom metadata attributes that your documents require.

The Schema.xml File

The schema is specified in an XML schema file called schema.xml within your Spotlight importer bundle.

The following XML fragment shows the general format of the file.

<?xml version="1.0" encoding="UTF-8"?>

<schema version="1.0" xmlns="http://www.apple.com/metadata"

                      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

                      xsi:schemaLocation="http://www.apple.com/metadata

file:///System/Library/Frameworks/CoreServices.framework/Frameworks/Metadata.framework/

Resources/MetadataSchema.xsd">

    <attributes>

    ...

   </attributes>

    <types>

        <type name="SUPPORTED_UTI_TYPE">

            <allattrs>

        ...

            </allattrs>

            <displayattrs>

        ...

            </displayattrs>

        </type>

    </types>

</schema>

Specifying Custom Attributes

Custom attributes for your Spotlight importer are declared as attribute elements that are children of the attributes element. The XML attributes for the attribute element are shown in Table 1.

The following is an example XML fragment for the attributes element of a schema.

<attributes>

    <attribute name="com_apple_myCocoaDocumentApp_myCustomDocument_notes" multivalued="false" type="CFString"/>

</attributes>

Specifying the Attributes for a Document

There is a single type element for each document type that your importer can read. The XML attributes for the type element are shown in Table 2.

A type element specifies the metadata attributes that it returns in the allattrs element, separating each name with whitespace. The allattrs element should contain all the elements related to your custom document.

The metadata attributes to be displayed for previewing for a document—for example in Finder’s Get Info panel—are listed within the displayattrs element, separating each name with whitespace.

The following is an example XML fragment for a types element of a schema.

<types>

    <type name="com.apple.mycocoadocumentapp.mycustomdocument">

        <allattrs>

            com_apple_myCocoaDocumentApp_myCustomDocument_notes

        </allattrs>

        <displayattrs>

            com_apple_myCocoaDocumentApp_myCustomDocument_notes

        </displayattrs>

    </type>

</types>