Filter Drag/Drop NSViews With CFBundleDocumentTypes

Question

I have a Drag/Drop NSView which should accept the same file types and extensions that I have listed in my plist under the key CFBundleDocumentTypes. The app accepts any type of video file, folders and several file extensions that aren't picked up by the public.movie type.

The (rather long) list of CFBundleDocumentTypes is:

    <key>CFBundleDocumentTypes</key>
<array>
    <dict>
        <key>CFBundleTypeName</key>
        <string>Folder</string>
        <key>CFBundleTypeOSTypes</key>
        <array>
            <string>fold</string>
        </array>
        <key>CFBundleTypeRole</key>
        <string>Viewer</string>
    </dict>
    <dict>
        <key>CFBundleTypeName</key>
        <string>Movies</string>
        <key>CFBundleTypeRole</key>
        <string>Viewer</string>
        <key>LSItemContentTypes</key>
        <array>
            <string>public.movie</string>
        </array>
    </dict>
    <dict>
        <key>CFBundleTypeExtensions</key>
        <array>
            <string>flv</string>
        </array>
        <key>CFBundleTypeName</key>
        <string>Flash Video File</string>
        <key>CFBundleTypeRole</key>
        <string>Viewer</string>
    </dict>
    <dict>
        <key>CFBundleTypeExtensions</key>
        <array>
            <string>ram</string>
            <string>rm</string>
            <string>rmvb</string>
        </array>
        <key>CFBundleTypeName</key>
        <string>RealPlayer Media Files</string>
        <key>CFBundleTypeRole</key>
        <string>Viewer</string>
    </dict>
    <dict>
        <key>CFBundleTypeExtensions</key>
        <array>
            <string>vob</string>
        </array>
        <key>CFBundleTypeName</key>
        <string>VOB File (DVD Video)</string>
        <key>CFBundleTypeRole</key>
        <string>Viewer</string>
    </dict>
    <dict>
        <key>CFBundleTypeExtensions</key>
        <array>
            <string>ogm</string>
        </array>
        <key>CFBundleTypeName</key>
        <string>Ogg MPEG-4 Video File</string>
        <key>CFBundleTypeRole</key>
        <string>Viewer</string>
    </dict>
    <dict>
        <key>CFBundleTypeExtensions</key>
        <array>
            <string>ogv</string>
        </array>
        <key>CFBundleTypeMIMETypes</key>
        <array>
            <string>video/ogg</string>
        </array>
        <key>CFBundleTypeName</key>
        <string>Ogg Video File</string>
        <key>CFBundleTypeRole</key>
        <string>Viewer</string>
    </dict>
    <dict>
        <key>CFBundleTypeExtensions</key>
        <array>
            <string>axv</string>
        </array>
        <key>CFBundleTypeMIMETypes</key>
        <array>
            <string>video/annodex</string>
        </array>
        <key>CFBundleTypeName</key>
        <string>Annodex Video File</string>
        <key>CFBundleTypeRole</key>
        <string>Viewer</string>
    </dict>
    <dict>
        <key>CFBundleTypeExtensions</key>
        <array>
            <string>avi</string>
        </array>
        <key>CFBundleTypeName</key>
        <string>AVI container</string>
        <key>CFBundleTypeRole</key>
        <string>Viewer</string>
    </dict>
    <dict>
        <key>CFBundleTypeExtensions</key>
        <array>
            <string>mov</string>
            <string>moov</string>
            <string>qt</string>
        </array>
        <key>CFBundleTypeMIMETypes</key>
        <array>
            <string>video/quicktime</string>
        </array>
        <key>CFBundleTypeName</key>
        <string>Apple QuickTime container</string>
        <key>CFBundleTypeRole</key>
        <string>Viewer</string>
    </dict>
    <dict>
        <key>CFBundleTypeExtensions</key>
        <array>
            <string>divx</string>
        </array>
        <key>CFBundleTypeName</key>
        <string>DivX file</string>
        <key>CFBundleTypeRole</key>
        <string>Viewer</string>
    </dict>
    <dict>
        <key>CFBundleTypeExtensions</key>
        <array>
            <string>dv</string>
        </array>
        <key>CFBundleTypeName</key>
        <string>DV file</string>
        <key>CFBundleTypeRole</key>
        <string>Viewer</string>
    </dict>
    <dict>
        <key>CFBundleTypeExtensions</key>
        <array>
            <string>wmv</string>
            <string>wm</string>
        </array>
        <key>CFBundleTypeName</key>
        <string>Windows Media Video</string>
        <key>CFBundleTypeRole</key>
        <string>Viewer</string>
    </dict>
    <dict>
        <key>CFBundleTypeExtensions</key>
        <array>
            <string>mpg</string>
            <string>mpeg</string>
            <string>mpeg1</string>
            <string>mpeg2</string>
        </array>
        <key>CFBundleTypeName</key>
        <string>multiplexed MPEG-1/2</string>
        <key>CFBundleTypeRole</key>
        <string>Viewer</string>
    </dict>
    <dict>
        <key>CFBundleTypeExtensions</key>
        <array>
            <string>m1v</string>
        </array>
        <key>CFBundleTypeName</key>
        <string>MPEG-1 Video File</string>
        <key>CFBundleTypeRole</key>
        <string>Viewer</string>
    </dict>
    <dict>
        <key>CFBundleTypeExtensions</key>
        <array>
            <string>ts</string>
            <string>m2ts</string>
            <string>mts</string>
            <string>mt2s</string>
        </array>
        <key>CFBundleTypeMIMETypes</key>
        <array>
            <string>video/mp2t</string>
        </array>
        <key>CFBundleTypeName</key>
        <string>MPEG-2 Transport Stream</string>
        <key>CFBundleTypeRole</key>
        <string>Viewer</string>
    </dict>
    <dict>
        <key>CFBundleTypeExtensions</key>
        <array>
            <string>m2v</string>
            <string>mpv</string>
        </array>
        <key>CFBundleTypeName</key>
        <string>MPEG-2 Video File</string>
        <key>CFBundleTypeRole</key>
        <string>Viewer</string>
    </dict>
    <dict>
        <key>CFBundleTypeExtensions</key>
        <array>
            <string>mp4</string>
            <string>mpeg4</string>
            <string>m4v</string>
        </array>
        <key>CFBundleTypeName</key>
        <string>MPEG-4 File</string>
        <key>CFBundleTypeRole</key>
        <string>Viewer</string>
    </dict>
    <dict>
        <key>CFBundleTypeExtensions</key>
        <array>
            <string>3gp</string>
        </array>
        <key>CFBundleTypeName</key>
        <string>3GPP File</string>
        <key>CFBundleTypeRole</key>
        <string>Viewer</string>
    </dict>
    <dict>
        <key>CFBundleTypeExtensions</key>
        <array>
            <string>mkv</string>
        </array>
        <key>CFBundleTypeName</key>
        <string>Matroska Video File</string>
        <key>CFBundleTypeRole</key>
        <string>Viewer</string>
    </dict>
    <dict>
        <key>CFBundleTypeExtensions</key>
        <array>
            <string>webm</string>
        </array>
        <key>CFBundleTypeName</key>
        <string>WebM Video File</string>
        <key>CFBundleTypeRole</key>
        <string>Viewer</string>
    </dict>
    <dict>
        <key>CFBundleTypeExtensions</key>
        <array>
            <string>nuv</string>
        </array>
        <key>CFBundleTypeName</key>
        <string>NuppleVideo File</string>
        <key>CFBundleTypeRole</key>
        <string>Viewer</string>
        <key>LSTypeIsPackage</key>
        <false/>
        <key>NSPersistentStoreTypeKey</key>
        <string>Binary</string>
    </dict>
</array>

I am already able to verify drop acceptance in my NSView's draggingEntered method, but I want to be able to run through the Info.plist entries for CFBundleDocumentTypes instead of duplicating all the entries in this method. How can I do this so that my view accepts the exact same files as listed in the CFBundleDocumentTypes entry?

Answer 1

Just ask your bundle for the information:

NSArray* documentTypes = [[[NSBundle mainBundle] infoDictionary]
                                    objectForKey:@"CFBundleDocumentTypes"];

This will return an array of dictionaries, one for each of the file types, from which you can easily extract the other information:

for(NSDictionary* docInfo in documentTypes)
{
    NSArray* fileExtensions = [docInfo objectForKey:@"CFBundleTypeExtensions"];
    //do something with this info
}

You could use this in conjunction with the -documentClassForType: method of NSDocumentController. This takes the value from the CFBundleTypeName Info.plist key as the type.