I Need Closure(s)

While planning my approach into CLSQL to add Fuzzy SQL, I found myself wanting to just search for keywords, Spotlight-style. Well, how hard can it be? Not that hard, as it turns out. I basically just want to throw the text of a file to Spotlight and have it index the contents. Even if you have no Objective C or Cocoa experience like me, copying and modifying code is pretty straightforward.

I started with this article on Creating Spotlight Plugins. In the info.plist, I substituted his type of "com.apple.stickies.aaa" with "com.lisp.lisp", and "lisp" as the file extension. In the schema.xml, I made a custom metata for lisp files called com_lisp_lisp_data.

The XCode project makes a file called 'GetMetaDataForFile.c', which gets renamed to 'GetMetaDataForFile.m' since we use Objective C and Cocoa. The meat of this file is a callback function called 'GetMetaDataForFile'. All I do in this function is read the entire file into a NSString and add it to the 'mutable dictionary'.

Here's the function:

Boolean GetMetadataForFile(
void* thisInterface,
CFMutableDictionaryRef attributes,
CFStringRef contentTypeUTI,
CFStringRef pathToFile)
{
Boolean success=NO;
NSAutoreleasePool *pool;

// Don't assume that there is an autorelease pool
//around the calling of this function.
pool = [[NSAutoreleasePool alloc] init];

/* Pull any available metadata from the file */

NSString *fileText = [NSString stringWithContentsOfFile:pathToFile];

[(NSMutableDictionary *)attributes setObject:fileText
forKey:@"com_lisp_lisp_data"];

// return YES so that the attributes are imported and
// add more resilient error handling at your own discretion
success=YES;

//memory management
[pool release];

return success;
}

Build this in XCode, then:

My-Computer:~/LispImporter/build rrc$ sudo cp -r LispImporter.mdimporter /Library/Spotlight

We start with a small lisp file:
My-Computer:~/LispImporter/build rrc$ cat ~/small.lisp
;; A small lisp file
(format t "This is a small lisp file")

Index this file:
My-Computer:~/LispImporter/build rrc$ mdimport -d1 ~/small.lisp
2005-08-21 20:41:05.624 mdimport[630] Import '/Users/rrc/small.lisp' type 'com.lisp.lisp' using 'file://localhost/Library/Spotlight/LispImporter.mdimporter/'

See what Spotlight thinks about this file. Note the 'com_lisp_lisp_data' attribute:
My-Computer:~/LispImporter/build rrc$ mdls ~/small.lisp
/Users/rrc/small.lisp -------------
com_lisp_lisp_data = ";; A small lisp file (format t "This is a small lisp file") "
kMDItemAttributeChangeDate = 2005-08-21 20:41:05 -0400
kMDItemContentCreationDate = 2005-08-21 20:37:33 -0400
kMDItemContentModificationDate = 2005-08-21 20:37:33 -0400
kMDItemContentType = "com.lisp.lisp"
kMDItemContentTypeTree = ("com.lisp.lisp", "public.data", "public.item", "public.content")
kMDItemDisplayName = "small.lisp"
kMDItemFSContentChangeDate = 2005-08-21 20:37:33 -0400
kMDItemFSCreationDate = 2005-08-21 20:37:33 -0400
kMDItemFSCreatorCode = 0
kMDItemFSFinderFlags = 0
kMDItemFSInvisible = 0
kMDItemFSLabel = 0
kMDItemFSName = "small.lisp"
kMDItemFSNodeCount = 0
kMDItemFSOwnerGroupID = 501
kMDItemFSOwnerUserID = 501
kMDItemFSSize = 60
kMDItemFSTypeCode = 0
kMDItemID = 1604367
kMDItemKind = "Document"
kMDItemLastUsedDate = 2005-08-21 20:37:33 -0400
kMDItemUsedDates = (2005-08-21 20:37:33 -0400)

Great! Now tell Spotlight to do all the lisp files:
My-Computer:~/LispImporter/build rrc$ mdimport -r /Library/Spotlight/LispImporter.mdimporter
2005-08-21 20:43:47.750 mdimport[633] Asking server to reimport files with UTIs: ("dyn.ah62d4rv4gk8y2wnxna", "dyn.ah62d4rv4ge8024pxsa", "com.lisp.lisp")

Go away for a while...
Then give it a try.