Database Reference
In-Depth Information
In the
-metadataFolder
, we first request a list of the cache directories from the
NSSearchPathForDirectoriesInDomain
method and append the path components
Metadata
and
GrokkingRecipes
to it. We do not check to see whether the path exists
at this point but instead let our caller decide how to handle that.
Creating the Spotlight Importer
Now that we have some metadata to work with, it's time to build the Spotlight
importer. To start this part of the application, we need to first address
UTI
s.
Uniform Type Identifiers (UTIs)
Both Spotlight and Quick Look use
UTI
s rather than filename extensions to
connect files on disk with (Spotlight) importers and (Quick Look) generators.
A
UTI
is a unique string that identifies the type of data stored in a given file.
It is recommended that
UTI
s identify the company and application that created
the data file, and like bundle identifiers, a reverse domain name is ideal for
this purpose. (It should be noted that bundle identifiers are in fact
UTI
s
themselves.) Since our application uses
com.pragprog.grokkingrecipes
as its unique
bundle identifier, we will use the same
UTI
as the value of the
LSItemContentTypes
to identify the files.
<key>
CFBundleDocumentTypes
</key>
<array>
<dict>
<key>
CFBundleTypeExtensions
</key>
<array>
<string>
grokkingrecipe
</string>
</array>
<key>
CFBundleTypeIconFile
</key>
<string>
book.icns
</string>
<key>
CFBundleTypeName
</key>
<string>
Grokking Recipe
</string>
<key>
CFBundleTypeRole
</key>
<string>
Editor
</string>
<key>
LSItemContentTypes
</key>
<array>
<string>
com.pragprog.grokkingrecipe
</string>
</array>
<key>
NSPersistentStoreTypeKey
</key>
<string>
XML
</string>
</dict>
</array>
The
UTExportedTypeDeclarations
section is probably very familiar. Xcode generates
it to describe any file that is handled by the application being built. The one
difference is that, instead of defining a file extension (like
.txt
), we are defining
