root/trunk/Importer/GetMetadataForFile.m

#import <CoreServices/CoreServices.h> 
#import <Foundation/Foundation.h>
#import <libxml/tree.h>
#import <libxml/xmlerror.h>

/* Sample transcript:
<log began="2005-07-11 12:19:09 -0400" source="irc://irc.freenode.net/%23barcamp">
 <event id="H5OI9GYEXB" name="memberJoined" occurred="2005-08-20 22:13:28 -0400">
  <message><span class="member">vdwal</span> joined the chat room.</message>
  <who hostmask="n=vanderwa@dsl092-170-254.wdc2.dsl.speakeasy.net">vdwal</who>
 </event>
 <envelope>
  <sender hostmask="i=urgy@c-67-188-71-51.hsd1.ca.comcast.net">urgen</sender>
  <message id="H7DJHOYEXB" received="2005-08-20 22:13:36 -0400">hi</message>
 </envelope>
 <envelope>
  <sender hostmask="n=vanderwa@dsl092-170-254.wdc2.dsl.speakeasy.net">vdwal</sender>
  <message id="XVQ44ZYEXB" received="2005-08-20 22:13:47 -0400">where did everybody go?</message>
  <message id="GD3YCAZEXB" received="2005-08-20 22:13:58 -0400">hi</message>
  <message id="D0TAANZEXB" received="2005-08-20 22:14:11 -0400">i lost my nickname and my legs</message>
  <message id="H5CJHSZEXB" received="2005-08-20 22:14:16 -0400">stuck again</message>
 </envelope>
</log>
*/

@interface JVChatTranscriptMetadataExtractor : NSObject {
        BOOL inEnvelope;
        BOOL inMessage;
        NSString *lastElement;
        NSDate *dateStarted;
        NSString *lastEventDate;
        NSString *source;
        NSMutableString *content;
        NSMutableSet *participants;
        NSCharacterSet *lineBreaks;
}
- (id) initWithCapacity:(unsigned) capacity;
- (NSDictionary *) metadataAttributes;
@end

@implementation JVChatTranscriptMetadataExtractor
- (id) initWithCapacity:(unsigned) capacity {
        if( ( self = [super init] ) ) {
                content = [[NSMutableString alloc] initWithCapacity:capacity];
                participants = [[NSMutableSet alloc] initWithCapacity:400];
                lineBreaks = [[NSCharacterSet characterSetWithCharactersInString:@"\n\r"] retain];
        }

        return self;
}

- (void) dealloc {
        [lastElement release];
        [content release];
        [participants release];
        [dateStarted release];
        [lastEventDate release];
        [source release];
        [lineBreaks release];

        lastElement = nil;
        content = nil;
        participants = nil;
        dateStarted = nil;
        lastEventDate = nil;
        source = nil;
        lineBreaks = nil;

        [super dealloc];
}

- (NSDictionary *) metadataAttributes {
        NSMutableDictionary *ret = [NSMutableDictionary dictionary];
        [ret setObject:content forKey:(NSString *) kMDItemTextContent];

        if( dateStarted ) [ret setObject:dateStarted forKey:(NSString *) kMDItemContentCreationDate];
        if( [lastEventDate length] ) {
                NSDate *lastDate = [NSDate dateWithString:lastEventDate];
                if( lastDate ) {
                        [ret setObject:lastDate forKey:(NSString *) kMDItemContentModificationDate];
                        [ret setObject:lastDate forKey:(NSString *) kMDItemLastUsedDate];

                        if( dateStarted ) {
                                // Set Duration
                                NSTimeInterval logDuration = [lastDate timeIntervalSinceDate:dateStarted];
                                [ret setObject:[NSNumber numberWithInt:logDuration] forKey:(NSString *) kMDItemDurationSeconds];

                                // Set Coverage
                                NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
                                [formatter setFormatterBehavior:NSDateFormatterBehavior10_4];
                                [formatter setDateStyle:NSDateFormatterShortStyle];
                                [formatter setTimeStyle:NSDateFormatterShortStyle];

                                NSString *coverageWording = [NSString stringWithFormat:@"%@ - %@", [formatter stringFromDate:dateStarted], [formatter stringFromDate:lastDate]];
                                [ret setObject:coverageWording forKey:(NSString *) kMDItemCoverage];
                                [formatter release];
                        }                       
                }
        }

        if( [participants count] ) [ret setObject:[participants allObjects] forKey:(NSString *) kMDItemContributors];
        if( [source length] ) [ret setObject:source forKey:(NSString *) kMDItemWhereFroms];

        [ret setObject:[NSArray arrayWithObject:@"transcript"] forKey:(NSString *) kMDItemKind];
        [ret setObject:[NSArray arrayWithObject:@"Colloquy"] forKey:(NSString *) kMDItemCreator];

        return ret;
}

- (void) parser:(NSXMLParser *) parser didStartElement:(NSString *) elementName namespaceURI:(NSString *) namespaceURI qualifiedName:(NSString *) qName attributes:(NSDictionary *) attributes {
        [lastElement release];
        lastElement = [elementName retain];

        if( [elementName isEqualToString:@"envelope"] ) inEnvelope = YES;
        else if( inEnvelope && [elementName isEqualToString:@"message"] ) {
                inMessage = YES;
                NSString *date = [attributes objectForKey:@"received"];
                if( date ) {
                        [lastEventDate release];
                        lastEventDate = [date retain];
                        if( ! dateStarted ) dateStarted = [[NSDate alloc] initWithString:date];
                }
        } else if( ! inEnvelope && [elementName isEqualToString:@"event"] ) {
                NSString *date = [attributes objectForKey:@"occurred"];
                if( date ) {
                        [lastEventDate release];
                        lastEventDate = [date retain];
                        if( ! dateStarted ) dateStarted = [[NSDate alloc] initWithString:date];
                }
        } else if( ! inEnvelope && [elementName isEqualToString:@"log"] ) {
                NSString *date = [attributes objectForKey:@"began"];
                if( date && ! dateStarted ) dateStarted = [[NSDate alloc] initWithString:date];
                if( ! source ) source = [[attributes objectForKey:@"source"] retain];
        }
}

- (void) parser:(NSXMLParser *) parser didEndElement:(NSString *) elementName namespaceURI:(NSString *) namespaceURI qualifiedName:(NSString *) qName {
        if( inEnvelope && [elementName isEqualToString:@"envelope"] ) inEnvelope = NO;
        else if( inEnvelope && inMessage && [elementName isEqualToString:@"message"] ) {
                inMessage = NO;
                [content appendString:@"\n"]; // append a newline after messages
        }

        [lastElement release];
        lastElement = nil;
}

- (void) parser:(NSXMLParser *) parser foundCharacters:(NSString *) string {
        if( inEnvelope && inMessage ) {
                NSString *newString = [string stringByTrimmingCharactersInSet:lineBreaks];
                if( [newString length] ) [content appendString:newString];
        } else if( inEnvelope && [lastElement isEqualToString:@"sender"] ) {
                if( [string length] ) [participants addObject:string];
        }
}
@end

Boolean GetMetadataForFile( void *thisInterface, CFMutableDictionaryRef attributes, CFStringRef contentTypeUTI, CFStringRef pathToFile );

Boolean GetMetadataForFile( void *thisInterface, CFMutableDictionaryRef attributes, CFStringRef contentTypeUTI, CFStringRef pathToFile ) {
        NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];

        NSFileManager *fm = [NSFileManager defaultManager];

        if( ! [fm fileExistsAtPath:(NSString *) pathToFile] ) goto end;
        if( ! [fm isReadableFileAtPath:(NSString *) pathToFile] ) goto end;

        NSURL *file = [NSURL fileURLWithPath:(NSString *) pathToFile];
        NSXMLParser *parser = [[NSXMLParser alloc] initWithContentsOfURL:file];

        unsigned long long fileSize = [[fm fileAttributesAtPath:(NSString *) pathToFile traverseLink:YES] fileSize];
        unsigned capacity = ( fileSize ? fileSize / 3 : 5000 ); // the message content takes up about a third of the XML file's size

        JVChatTranscriptMetadataExtractor *extractor = [[JVChatTranscriptMetadataExtractor alloc] initWithCapacity:capacity];

        [parser setDelegate:extractor];
        [parser parse];

        [(NSMutableDictionary *) attributes addEntriesFromDictionary:[extractor metadataAttributes]];

        [parser release];
        [extractor release];

        xmlSetStructuredErrorFunc( NULL, NULL );

end:
        [pool release];
    return TRUE;
}