SSRSS.m

/*
 
 BSD License
 
 Copyright (c) 2002, Brent Simmons
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without modification,
 are permitted provided that the following conditions are met:
 
 *	Redistributions of source code must retain the above copyright notice,
 this list of conditions and the following disclaimer.
 *	Redistributions in binary form must reproduce the above copyright notice,
 this list of conditions and the following disclaimer in the documentation
 and/or other materials provided with the distribution.
 *	Neither the name of ranchero.com or Brent Simmons nor the names of its
 contributors may be used to endorse or promote products derived
 from this software without specific prior written permission.
 
 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
 BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 
 */

/*
 RSS.m
 A class for reading RSS feeds.
 
 Created by Brent Simmons on Wed Apr 17 2002.
 Copyright (c) 2002 Brent Simmons. All rights reserved.
 */


#import "SSRSS.h"

@implementation SSRSS


#define titleKey @"title"
#define linkKey @"link"
#define descriptionKey @"description"


/*Public interface*/


- (SSRSS *) initWithTitle: (NSString *) title andDescription: (NSString *) description {
	
	/*
	 Create an empty feed. Useful for synthetic feeds.
	 */
	
	NSMutableDictionary *header;
	
	flRdf = NO;
	
	header = [NSMutableDictionary dictionaryWithCapacity: 2];
	
	[header setObject: title forKey: titleKey];
	
	[header setObject: description forKey: descriptionKey];
	
	headerItems = (NSDictionary *) [header copy];
	
	newsItems = [[NSMutableArray alloc] initWithCapacity: 0];
	
	version = [[NSString alloc] initWithString: @"synthetic"];
	
	return (self);
} /*initWithTitle*/


- (SSRSS *) initWithData:(NSData *) rssData normalize:(BOOL)fl {
	if ((self = [super init])) {
		CFXMLTreeRef tree = NULL ;
		flRdf = NO;
		normalize = fl;
		
		if (rssData) {
			NS_DURING
			
			tree = CFXMLTreeCreateFromData (kCFAllocatorDefault, (CFDataRef)rssData,
											NULL,  kCFXMLParserSkipWhitespace, kCFXMLNodeCurrentVersion);
			
			NS_HANDLER
			NSLog(@"System raised exception while parsing RSS data.") ;
			
			tree = nil ;
			// See http://lists.apple.com/archives/Objc-language/2008/Sep/msg00133.html ...
			[super dealloc] ;
			self = nil ;
			
			NS_ENDHANDLER
		}
		
		if (tree) {
			[self createheaderdictionary: tree];
			[self createitemsarray: tree];
			[self setversionstring: tree];
			CFXMLNodeRef node = CFXMLTreeGetNode (tree);
			CFXMLDocumentInfo* documentInfo ;
			documentInfo = (CFXMLDocumentInfo*)CFXMLNodeGetInfoPtr(node) ;
			encoding = documentInfo->encoding ;
			CFRelease (tree);
		}
		else {
			NSString* dataString = [[NSString alloc] initWithData:rssData encoding:NSASCIIStringEncoding] ;
			// We used ASCII because if the string is corrupt UTF8 may fail
			[dataString release] ;
			
			NSString* filePath = [NSString stringWithFormat:
								  @"%@/Desktop/GoogleBad.%@.%i.data",
								  NSHomeDirectory(),
								  NSUserName(),
								  [[NSDate date] timeIntervalSinceReferenceDate]] ;
			NSString* msg = @"Could not parse data from Google containing some bookmarks.\n\n Some of your Google Bookmarks may be missing.\n\nFile containing bad data was written to your desktop." ;
			[rssData writeToFile:filePath atomically:NO] ;
			NSRunCriticalAlertPanel(nil, msg, nil, nil, nil) ;
			
			// See http://lists.apple.com/archives/Objc-language/2008/Sep/msg00133.html ...
			[super dealloc] ;
			self = nil ;
		}
	}
	else {
		self = nil ;
	}
	
	return self ;
}


- (NSDictionary *) headerItems {
	
	return (headerItems);
} /*headerItems*/


- (NSMutableArray *) newsItems {
	
	return (newsItems);
} /*newsItems*/


- (NSString *) version {
	
	return (version);
} /*version*/


- (CFStringEncoding) encoding {
	
	return (encoding);
} /*encoding*/


- (void) dealloc {
	
	[headerItems release] ;
	[newsItems release] ;
	[version release] ;
	
	[super dealloc] ;
} /*dealloc*/



/*Private methods. Don't call these: they may change.*/


- (void) createheaderdictionary: (CFXMLTreeRef) tree {
	
	CFXMLTreeRef channelTree, childTree;
	CFXMLNodeRef childNode;
	int childCount, i;
	NSString *childName;
	NSMutableDictionary *headerItemsMutable;
	
	channelTree = [self getchanneltree: tree];
	
	if (channelTree == nil) {
		
		NSException *exception = [NSException exceptionWithName: @"RSSCreateHeaderDictionaryFailed"
														 reason: @"Couldn't find the channel tree." userInfo: nil];
		
		[exception raise];
	} /*if*/
	
	childCount = CFTreeGetChildCount (channelTree);
	
	headerItemsMutable = [NSMutableDictionary dictionaryWithCapacity: childCount];
	
	for (i = 0; i < childCount; i++) {
		
		childTree = CFTreeGetChildAtIndex (channelTree, i);
		
		childNode = CFXMLTreeGetNode (childTree);
		
		childName = (NSString *) CFXMLNodeGetString (childNode);
		
		if ([childName hasPrefix: @"rss:"])
			childName = [childName substringFromIndex: 4];
		
		if ([childName isEqualToString: @"item"])
			break;
		
		if ([childName isEqualTo: @"image"])
			[self flattenimagechildren: childTree into: headerItemsMutable];
		
		[headerItemsMutable setObject: [self getelementvalue: childTree] forKey: childName];
	} /*for*/
	
	headerItems = [headerItemsMutable copy];
} /*initheaderdictionary*/


- (void) createitemsarray: (CFXMLTreeRef) tree {
	
	CFXMLTreeRef channelTree, childTree, itemTree;
	CFXMLNodeRef childNode, itemNode;
	NSString *childName;
	NSString *itemName, *itemValue;
	int childCount, itemChildCount, i, j;
	NSMutableDictionary *itemDictionaryMutable;
	NSMutableArray *itemsArrayMutable;
	
	if (flRdf)
		channelTree = [self getnamedtree: tree name: @"rdf:RDF"];
	else
		channelTree = [self getchanneltree: tree];
	
	if (channelTree == nil) {
		
		NSException *exception = [NSException exceptionWithName: @"RSSCreateItemsArrayFailed"
														 reason: @"Couldn't find the news items." userInfo: nil];
		
		[exception raise];
	} /*if*/
	
	childCount = CFTreeGetChildCount (channelTree);
	
	itemsArrayMutable = [NSMutableArray arrayWithCapacity: childCount];
	
	for (i = 0; i < childCount; i++) {
		
		childTree = CFTreeGetChildAtIndex (channelTree, i);
		
		childNode = CFXMLTreeGetNode (childTree);
		
		childName = (NSString *) CFXMLNodeGetString (childNode);
		
		if ([childName hasPrefix: @"rss:"])
			childName = [childName substringFromIndex: 4];
		
		if (![childName isEqualToString: @"item"])
			continue;
		
		itemChildCount = CFTreeGetChildCount (childTree);
		
		itemDictionaryMutable = [NSMutableDictionary dictionaryWithCapacity: itemChildCount];
		
		for (j = 0; j < itemChildCount; j++) {
			
			itemTree = CFTreeGetChildAtIndex (childTree, j);
			
			itemNode = CFXMLTreeGetNode (itemTree);
			
			itemName = (NSString *) CFXMLNodeGetString (itemNode);
			
			if ([itemName hasPrefix: @"rss:"])
				itemName = [itemName substringFromIndex: 4];
			
			itemValue = [self getelementvalue: itemTree];
			
			// We never see this in Google Bookmarks
			//if ([itemName isEqualToString: @"source"])
			//	[self flattensourceattributes: itemNode into: itemDictionaryMutable];
			
			// By Jerry: If an item is repeated (such as Google Bookmarks' label, should concatenate)
#define GOOGLE_LABEL_NAME @"smh:bkmk_label" 
			if ([itemName isEqualToString:GOOGLE_LABEL_NAME]) {
				NSString* existingLabels = [itemDictionaryMutable objectForKey:GOOGLE_LABEL_NAME] ;
				if (existingLabels) {
					itemValue = [NSString stringWithFormat:
								 @"%@, %@", existingLabels, itemValue] ;
				}
			}
			
			[itemDictionaryMutable setObject: itemValue forKey: itemName];
		} /*for*/
		
		if (normalize)
			[self normalizeRSSItem: itemDictionaryMutable];
		
		[itemsArrayMutable addObject: itemDictionaryMutable];
	} /*for*/
	
	newsItems = [itemsArrayMutable copy];
} /*createitemsarray*/


- (void) setversionstring: (CFXMLTreeRef) tree {
	
	CFXMLTreeRef rssTree;
	const CFXMLElementInfo *elementInfo;
	CFXMLNodeRef node;
	
	if (flRdf) {
		
		version = [[NSString alloc] initWithString: @"rdf"];
		
		return;
	} /*if*/
	
	rssTree = [self getnamedtree: tree name: @"rss"];
	
	node = CFXMLTreeGetNode (rssTree);
	
	elementInfo = CFXMLNodeGetInfoPtr (node);
	
	version = [[NSString alloc] initWithString: [(NSDictionary *) (*elementInfo).attributes objectForKey: @"version"]];	
} /*setversionstring*/


- (void) flattenimagechildren: (CFXMLTreeRef) tree into: (NSMutableDictionary *) dictionary {
	
	int childCount = CFTreeGetChildCount (tree);
	int i = 0;
	CFXMLTreeRef childTree;
	CFXMLNodeRef childNode;
	NSString *childName, *childValue, *keyName;
	
	if (childCount < 1)
		return;
	
	for (i = 0; i < childCount; i++) {
		
		childTree = CFTreeGetChildAtIndex (tree, i);
		
		childNode = CFXMLTreeGetNode (childTree);
		
		childName = (NSString *) CFXMLNodeGetString (childNode);
		
		if ([childName hasPrefix: @"rss:"])
			childName = [childName substringFromIndex: 4];
		
		childValue = [self getelementvalue: childTree];
		
		keyName = [NSString stringWithFormat: @"image%@", childName];
		
		[dictionary setObject: childValue forKey: keyName];
	} /*for*/
} /*flattenimagechildren*/


- (void) flattensourceattributes: (CFXMLNodeRef) node into: (NSMutableDictionary *) dictionary {
	
	const CFXMLElementInfo *elementInfo;
	NSString *sourceHomeUrl, *sourceRssUrl;
	
	elementInfo = CFXMLNodeGetInfoPtr (node);
	
	sourceHomeUrl = [(NSDictionary *) (*elementInfo).attributes objectForKey: @"homeUrl"];
	
	sourceRssUrl = [(NSDictionary *) (*elementInfo).attributes objectForKey: @"url"];
	
	if (sourceHomeUrl != nil)
		[dictionary setObject: sourceHomeUrl forKey: @"sourceHomeUrl"];
	
	if (sourceRssUrl != nil)
		[dictionary setObject: sourceRssUrl forKey: @"sourceRssUrl"];
} /*flattensourceattributes*/


- (CFXMLTreeRef) getchanneltree: (CFXMLTreeRef) tree {
	
	CFXMLTreeRef rssTree, channelTree;
	
	rssTree = [self getnamedtree: tree name: @"rss"];
	
	if (rssTree == nil) { /*It might be "rdf:RDF" instead, a 1.0 or greater feed.*/
		
		rssTree = [self getnamedtree: tree name: @"rdf:RDF"];
		
		if (rssTree != nil)		
			flRdf = YES; /*This info will be needed later when creating the items array.*/
	} /*if*/
	
	if (rssTree == nil)
		return (nil);
	
	channelTree = [self getnamedtree: rssTree name: @"channel"];
	
	if (channelTree == nil)
		channelTree = [self getnamedtree: rssTree name: @"rss:channel"];
	
	return (channelTree);
} /*getchanneltree*/


- (CFXMLTreeRef) getnamedtree: (CFXMLTreeRef) currentTree name: (NSString *) name {
	
	int childCount, index;
	CFXMLNodeRef xmlNode;
	CFXMLTreeRef xmlTreeNode;
	NSString *itemName;
	
	childCount = CFTreeGetChildCount (currentTree);
	
	for (index = childCount - 1; index >= 0; index--) {
		
		xmlTreeNode = CFTreeGetChildAtIndex (currentTree, index);
		
		xmlNode = CFXMLTreeGetNode (xmlTreeNode);
		
		itemName = (NSString *) CFXMLNodeGetString (xmlNode);
		
		if ([itemName isEqualToString: name])
			return (xmlTreeNode);
	} /*for*/
	
	return (nil);
} /*getnamedtree*/


- (void) normalizeRSSItem: (NSMutableDictionary *) rssItem {
	
	/*
	 Make sure item, link, and description are present and have
	 reasonable values. Description and link may be "".
	 Also trim white space, remove HTML when appropriate.
	 */
	
	NSString *description, *link, *title;
	BOOL nilDescription = NO;
	
	/*Description*/
	
	description = [rssItem objectForKey: descriptionKey];
	
	if (description == nil) {
		
		description = @"";
		
		nilDescription = YES;
	} /*if*/
	
	description = [description trimWhiteSpace];
	
	if ([description isEqualTo: @""])
		nilDescription = YES;
	
	[rssItem setObject: description forKey: descriptionKey];
	
	/*Link*/
	
	link = [rssItem objectForKey: linkKey];
	
	if ([NSString stringIsEmpty: link]) {
		
		/*Try to get a URL from the description.*/
		
		if (!nilDescription) {
			
			NSArray *stringComponents = [description componentsSeparatedByString: @"href=\""];
			
			if ([stringComponents count] > 1) {
				
				link = [stringComponents objectAtIndex: 1];
				
				stringComponents = [link componentsSeparatedByString: @"\""];
				
				link = [stringComponents objectAtIndex: 0];			
			} /*if*/				
		} /*if*/
	} /*if*/
	
	if (link == nil)
		link = @"";
	
	link = [link trimWhiteSpace];
	
	[rssItem setObject: link forKey: linkKey];
	
	/*Title*/
	
	title = [rssItem objectForKey: titleKey];
	
	if (title != nil) {
		
		title = [title stripHTML];
		
		title = [title trimWhiteSpace];
	} /*if*/
	
	if ([NSString stringIsEmpty: title]) {
		
		/*Grab a title from the description.*/
		
		if (!nilDescription) {
			
			NSArray *stringComponents = [description componentsSeparatedByString: @">"];
			
			if ([stringComponents count] > 1) {
				
				title = [stringComponents objectAtIndex: 1];
				
				stringComponents = [title componentsSeparatedByString: @"<"];
				
				title = [stringComponents objectAtIndex: 0];
				
				title = [title stripHTML];
				
				title = [title trimWhiteSpace];
			} /*if*/
			
			if ([NSString stringIsEmpty: title]) { /*use first part of description*/
				
				NSString *shortTitle = [[[description stripHTML] trimWhiteSpace] ellipsizeAfterNWords: 5];
				
				shortTitle = [shortTitle trimWhiteSpace];
				
				title = [NSString stringWithFormat: @"%@...", shortTitle];				
			} /*else*/				
		} /*if*/
		
		title = [title stripHTML];
		
		title = [title trimWhiteSpace];
		
		if ([NSString stringIsEmpty: title])
			title = @"Untitled";	
	} /*if*/
	
	[rssItem setObject: title forKey: titleKey];
	
	/*dangerousmeta case: super-long title with no description*/
	
	if ((nilDescription) && ([title length] > 50)) {
		
		NSString *shortTitle = [[[title stripHTML] trimWhiteSpace] ellipsizeAfterNWords: 7];
		
		description = [[title copy] autorelease];
		
		[rssItem setObject: description forKey: descriptionKey];
		
		title = [NSString stringWithFormat: @"%@...", shortTitle];				
		
		[rssItem setObject: title forKey: titleKey];
	} /*if*/
	
	{ /*deal with entities*/
		
		const char *tempcstring;
		NSAttributedString *s = nil;
		NSString *convertedTitle = nil;
		NSArray *stringComponents;
		
		stringComponents = [title componentsSeparatedByString: @"&"];
		
		if ([stringComponents count] > 1) {
			
			stringComponents = [title componentsSeparatedByString: @";"];
			
			if ([stringComponents count] > 1) {
				
				int len;
				
				tempcstring = [title UTF8String];
				
				len = strlen (tempcstring);
				
				if (len > 0) {
					
					s = [[NSAttributedString alloc]
						 initWithHTML: [NSData dataWithBytes: tempcstring length: strlen (tempcstring)]
						 documentAttributes: (NSDictionary **) NULL];
					
					convertedTitle = [s string];
					
					[s autorelease];
					
					convertedTitle = [convertedTitle stripHTML];
					
					convertedTitle = [convertedTitle trimWhiteSpace];				
				} /*if*/
				
				if ([NSString stringIsEmpty: convertedTitle])
					convertedTitle = @"Untitled";
				
				[rssItem setObject: convertedTitle forKey: @"convertedTitle"];
			} /*if*/
		} /*if*/
	} /*deal with entities*/
} /*normalizeRSSItem*/


- (NSString *) getelementvalue: (CFXMLTreeRef) tree {
	
	CFXMLNodeRef node;
	CFXMLTreeRef itemTree;
	int childCount, ix;
	NSMutableString *valueMutable;
	NSString *value;
	NSString *name;
	
	childCount = CFTreeGetChildCount (tree);
	
	valueMutable = [[NSMutableString alloc] init];
	
	for (ix = 0; ix < childCount; ix++) {
		
		itemTree = CFTreeGetChildAtIndex (tree, ix);
		
		node = CFXMLTreeGetNode (itemTree);
		
		name = (NSString *) CFXMLNodeGetString (node);
		
		if (name != nil) {
			
			if (CFXMLNodeGetTypeCode (node) == kCFXMLNodeTypeEntityReference) {
				
				if ([name isEqualTo: @"lt"])
					name = @"<";
				
				else if ([name isEqualTo: @"gt"])
					name = @">";
				
				else if ([name isEqualTo: @"quot"])
					name = @"\"";
				
				else if ([name isEqualTo: @"amp"])
					name = @"&";
				
				else if ([name isEqualTo: @"rsquo"])
					name = [NSString stringWithFormat:@"%C", 8217];
				
				else if ([name isEqualTo: @"lsquo"])
					name = [NSString stringWithFormat:@"%C", 8216];
				
				else if ([name isEqualTo: @"apos"])
					name = @"'";				
				else
					name = [NSString stringWithFormat: @"&%@;", name];
			} /*if*/
			
			[valueMutable appendString: name];
		} /*if*/
	} /*for*/
	
	value = [valueMutable copy];
	
	[valueMutable autorelease];
	
	return ([value autorelease]);
} /*getelementvalue*/

@end