Matteo Caldari

A UISegmentedControl with custom color

matteo — Mon, 24 May 2010 09:24:58 +0000

Update: code for the class is now on GitHub. Also updated with BSD license and a fix for the next iOS version coming soon. If you have issues please use GitHub.

The color of a UISegmentedControl in the UIKit is customizable only in the bar style mode, so if one uses the plain or bordered mode, the only possible color is blue. This could be a problem if blue does not fit well in your app or in a view.

The only way to support other colors is to subclass the UISegmentedColor and draw the view yourself. That’s what I did in the MCSegmentedControl class, here’s how it looks with a green tint color.

Here compared with the standard UISegmentedControl, bordered style (mine is above):

and plain style:

and now with some ugly colors and font:

My implementation is not pixel identical to the Apple one, but it is very similar.

I added support for customizing the tint (i.e. the background of the selected segment), the color of the not selected items and of the selected item, plus, if the segment has an image, it is drawn as a mask, so it will always be in the same color as the text.

Example

// Instantiate as usual
NSArray *items = [NSArray arrayWithObjects:@"first", @"second", [UIImage imageNamed:@"image.png"], nil];
MCSegmentedControl *segmentedControl = [[MCSegmentedControl alloc] initWithItems:items];

// set frame, add to view, set target and action for value change as usual
segmentedControl.frame = CGRectMake(10.0f, 10.0f, 300.0f, 44.0f);
[self.view addSubview:segmentedControl];
[segmentedControl addTarget:self action:@selector(segmentedControlDidChange:) forControlEvents:UIControlEventValueChanged];

// Set a tint color
segmentedControl.tintColor = [UIColor orangeColor];

// Customize font and items color
segmentedControl.selectedItemColor = [UIColor yellowColor];
segmentedControl.unselectedItemColor = [UIColor darkGrayColor];

If you use Interface Builder, add a normal UISegmentedControl, set its class as MCSegmentedControl in the Identity Inspector, set the Tint in the Attributes Inspector.

At the moment, animations and the following UISegmentedControl methods are not supported:

- (void)setWidth:(CGFloat)width forSegmentAtIndex:(NSUInteger)segment;
- (void)setContentOffset:(CGSize)offset forSegmentAtIndex:(NSUInteger)segment

Here are the files: MCSegmentedControl.zip

Multiple contexts, controllers, delegates and CoreData bug

matteo — Mon, 09 Nov 2009 11:13:13 +0000

In a iPhone app I’m currently developing, I have a tipical Core Data object model with two entities (called Collection and Item) in a one-to-many relationship, and two table views for the entities, the second appearing when selecting a Collection in the first. The two table views have their own controller (which implements NSFetchedResultsControllerDelegate), managed object context and NSFetchedResultsController. The second table has has a reference to the Collection object, used to build a predicate in this way:

[NSPredicate predicateWithFormat:@"collection == %@", [self.collection objectID]]

In the first table view (the collections) everything works.
In the second (the items of a collection) when a new object is added, none of the NSFetchedResultsControllerDelegate methods gets called.
Moreover, when the name of an item is modified, the method controller:didChangeObject:atIndexPath:forChangeType:newIndexPath: is called, but with type NSFetchedResultsChangeDelete instead of NSFetchedResultsChangeUpdate.

The problem is that, because of a bug in NSFetchedResultsController (see this post on the Apple Developer Forum) , the NSPredicate above does a pointer comparison between two objects that are in two different contexts, so a possibile workaround until it get fixed would be something like this:

[NSPredicate predicateWithFormat:@"collection == %@", [self.managedObjectContext objectWithID:[self.collection objectID]]];

MGTwitterEngine status ID

matteo — Mon, 19 Oct 2009 13:56:21 +0000

update: this issue has been resolved, check out the official repository on GitHub

I was integrating the MGTwitterEngine in an iPhone App, and I noticed that there was something wrong with the status ID. In fact they were handled as int values, but the current ids are reaching 5billion, as you can see on the site Twitpocalypse.

So the solution is to treat them as long long int, which can be done editing the MGTwitterLibXMLParser.m file adding a method:

- (NSNumber *)_nodeValueAsLongLong
{
xmlChar *nodeValue = [self _nodeValue];
if (! nodeValue)
{
return nil;
}

NSString *intString = [NSString stringWithUTF8String:(const char *)nodeValue];
xmlFree(nodeValue);
return [NSNumber numberWithLongLong:[intString longLongValue]];
}

and using it:

215
216

// process element as an integer
NSNumber *number = [self _nodeValueAsLongLong];

Moreover, the MGTwitterEngine class must handle the updateID correctly:

//
// MGTwitterEngine.m
// MGTwitterEngine
//
// Created by Matt Gemmell on 10/02/2008.
// Copyright 2008 Instinctive Code.
//

#import "MGTwitterEngine.h"
#import "MGTwitterHTTPURLConnection.h"

#import "NSData+Base64.h"

#define USE_LIBXML 1

#if USE_LIBXML
#import "MGTwitterStatusesLibXMLParser.h"
#import "MGTwitterMessagesLibXMLParser.h"
#import "MGTwitterUsersLibXMLParser.h"
#import "MGTwitterMiscLibXMLParser.h"
#else
#import "MGTwitterStatusesParser.h"
#import "MGTwitterUsersParser.h"
#import "MGTwitterMessagesParser.h"
#import "MGTwitterMiscParser.h"
#endif

#define TWITTER_DOMAIN @"twitter.com"
#define HTTP_POST_METHOD @"POST"
#define MAX_MESSAGE_LENGTH 140 // Twitter recommends tweets of max 140 chars
#define MAX_LOCATION_LENGTH 31

#define DEFAULT_CLIENT_NAME @"MGTwitterEngine"
#define DEFAULT_CLIENT_VERSION @"1.0"
#define DEFAULT_CLIENT_URL @"http://mattgemmell.com/source"
#define DEFAULT_CLIENT_TOKEN @"mgtwitterengine"

#define URL_REQUEST_TIMEOUT 25.0 // Twitter usually fails quickly if it's going to fail at all.
#define DEFAULT_TWEET_COUNT 20

@interface MGTwitterEngine (PrivateMethods)

// Utility methods
- (NSDateFormatter *)_HTTPDateFormatter;
- (NSString *)_queryStringWithBase:(NSString *)base parameters:(NSDictionary *)params prefixed:(BOOL)prefixed;
- (NSDate *)_HTTPToDate:(NSString *)httpDate;
- (NSString *)_dateToHTTP:(NSDate *)date;
- (NSString *)_encodeString:(NSString *)string;

// Connection/Request methods
- (NSString *)_sendRequestWithMethod:(NSString *)method
path:(NSString *)path
queryParameters:(NSDictionary *)params
body:(NSString *)body
requestType:(MGTwitterRequestType)requestType
responseType:(MGTwitterResponseType)responseType;

// Parsing methods
- (void)_parseXMLForConnection:(MGTwitterHTTPURLConnection *)connection;

// Delegate methods
- (BOOL) _isValidDelegateForSelector:(SEL)selector;

@end

@implementation MGTwitterEngine

#pragma mark Constructors

+ (MGTwitterEngine *)twitterEngineWithDelegate:(NSObject *)theDelegate
{
return [[[MGTwitterEngine alloc] initWithDelegate:theDelegate] autorelease];
}

- (MGTwitterEngine *)initWithDelegate:(NSObject *)newDelegate
{
if (self = [super init]) {
_delegate = newDelegate; // deliberately weak reference
_connections = [[NSMutableDictionary alloc] initWithCapacity:0];
_clientName = [DEFAULT_CLIENT_NAME retain];
_clientVersion = [DEFAULT_CLIENT_VERSION retain];
_clientURL = [DEFAULT_CLIENT_URL retain];
_clientSourceToken = [DEFAULT_CLIENT_TOKEN retain];
_APIDomain = [TWITTER_DOMAIN retain];
_secureConnection = YES;
_clearsCookies = NO;
}

return self;
}

- (void)dealloc
{
_delegate = nil;

[[_connections allValues] makeObjectsPerformSelector:@selector(cancel)];
[_connections release];

[_username release];
[_password release];
[_clientName release];
[_clientVersion release];
[_clientURL release];
[_clientSourceToken release];
[_APIDomain release];

[super dealloc];
}

#pragma mark Configuration and Accessors

+ (NSString *)version
{
// 1.0.0 = 22 Feb 2008
// 1.0.1 = 26 Feb 2008
// 1.0.2 = 04 Mar 2008
// 1.0.3 = 04 Mar 2008
// 1.0.4 = 11 Apr 2008
// 1.0.5 = 06 Jun 2008
// 1.0.6 = 05 Aug 2008
// 1.0.7 = 28 Sep 2008
// 1.0.8 = 01 Oct 2008
return @"1.0.8";
}

- (NSString *)username
{
return [[_username retain] autorelease];
}

- (NSString *)password
{
return [[_password retain] autorelease];
}

- (void)setUsername:(NSString *)newUsername password:(NSString *)newPassword
{
// Set new credentials.
[_username release];
_username = [newUsername retain];
[_password release];
_password = [newPassword retain];

if ([self clearsCookies]) {
// Remove all cookies for twitter, to ensure next connection uses new credentials.
NSString *urlString = [NSString stringWithFormat:@"%@://%@",
(_secureConnection) ? @"https" : @"http",
_APIDomain];
NSURL *url = [NSURL URLWithString:urlString];

NSHTTPCookieStorage *cookieStorage = [NSHTTPCookieStorage sharedHTTPCookieStorage];
NSEnumerator *enumerator = [[cookieStorage cookiesForURL:url] objectEnumerator];
NSHTTPCookie *cookie = nil;
while (cookie = [enumerator nextObject]) {
[cookieStorage deleteCookie:cookie];
}
}
}

- (NSString *)clientName
{
return [[_clientName retain] autorelease];
}

- (NSString *)clientVersion
{
return [[_clientVersion retain] autorelease];
}

- (NSString *)clientURL
{
return [[_clientURL retain] autorelease];
}

- (NSString *)clientSourceToken
{
return [[_clientSourceToken retain] autorelease];
}

- (void)setClientName:(NSString *)name version:(NSString *)version URL:(NSString *)url token:(NSString *)token;
{
[_clientName release];
_clientName = [name retain];
[_clientVersion release];
_clientVersion = [version retain];
[_clientURL release];
_clientURL = [url retain];
[_clientSourceToken release];
_clientSourceToken = [token retain];
}

- (NSString *)APIDomain
{
return [[_APIDomain retain] autorelease];
}

- (void)setAPIDomain:(NSString *)domain
{
[_APIDomain release];
if (!domain || [domain length] == 0) {
_APIDomain = [TWITTER_DOMAIN retain];
} else {
_APIDomain = [domain retain];
}
}

- (BOOL)usesSecureConnection
{
return _secureConnection;
}

- (void)setUsesSecureConnection:(BOOL)flag
{
_secureConnection = flag;
}

- (BOOL)clearsCookies
{
return _clearsCookies;
}

- (void)setClearsCookies:(BOOL)flag
{
_clearsCookies = flag;
}

#pragma mark Connection methods

- (int)numberOfConnections
{
return [_connections count];
}

- (NSArray *)connectionIdentifiers
{
return [_connections allKeys];
}

- (void)closeConnection:(NSString *)identifier
{
MGTwitterHTTPURLConnection *connection = [_connections objectForKey:identifier];
if (connection) {
[connection cancel];
[_connections removeObjectForKey:identifier];
}
}

- (void)closeAllConnections
{
[[_connections allValues] makeObjectsPerformSelector:@selector(cancel)];
[_connections removeAllObjects];
}

#pragma mark Utility methods

- (NSDateFormatter *)_HTTPDateFormatter
{
// Returns a formatter for dates in HTTP format (i.e. RFC 822, updated by RFC 1123).
// e.g. "Sun, 06 Nov 1994 08:49:37 GMT"
NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
//[dateFormatter setDateFormat:@"%a, %d %b %Y %H:%M:%S GMT"]; // won't work with -init, which uses new (unicode) format behaviour.
[dateFormatter setFormatterBehavior:NSDateFormatterBehavior10_4];
[dateFormatter setDateFormat:@"EEE, dd MMM yyyy HH:mm:ss GMT"];
return dateFormatter;
}

- (NSString *)_queryStringWithBase:(NSString *)base parameters:(NSDictionary *)params prefixed:(BOOL)prefixed
{
// Append base if specified.
NSMutableString *str = [NSMutableString stringWithCapacity:0];
if (base) {
[str appendString:base];
}

// Append each name-value pair.
if (params) {
int i;
NSArray *names = [params allKeys];
for (i = 0; i < [names count]; i++) {
if (i == 0 && prefixed) {
[str appendString:@"?"];
} else if (i > 0) {
[str appendString:@"&"];
}
NSString *name = [names objectAtIndex:i];
[str appendString:[NSString stringWithFormat:@"%@=%@",
name, [self _encodeString:[params objectForKey:name]]]];
}
}

return str;
}

- (NSDate *)_HTTPToDate:(NSString *)httpDate
{
NSDateFormatter *dateFormatter = [self _HTTPDateFormatter];
return [dateFormatter dateFromString:httpDate];
}

- (NSString *)_dateToHTTP:(NSDate *)date
{
NSDateFormatter *dateFormatter = [self _HTTPDateFormatter];
return [dateFormatter stringFromDate:date];
}

- (NSString *)_encodeString:(NSString *)string
{
NSString *result = (NSString *)CFURLCreateStringByAddingPercentEscapes(NULL,
(CFStringRef)string,
NULL,
(CFStringRef)@";/?:@&=$+{}<>,",
kCFStringEncodingUTF8);
return [result autorelease];
}

- (NSString *)getImageAtURL:(NSString *)urlString
{
// This is a method implemented for the convenience of the client,
// allowing asynchronous downloading of users' Twitter profile images.
NSString *encodedUrlString = [urlString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURL *url = [NSURL URLWithString:encodedUrlString];
if (!url) {
return nil;
}

// Construct an NSMutableURLRequest for the URL and set appropriate request method.
NSMutableURLRequest *theRequest = [NSMutableURLRequest requestWithURL:url
cachePolicy:NSURLRequestReloadIgnoringCacheData
timeoutInterval:URL_REQUEST_TIMEOUT];

// Create a connection using this request, with the default timeout and caching policy,
// and appropriate Twitter request and response types for parsing and error reporting.
MGTwitterHTTPURLConnection *connection;
connection = [[MGTwitterHTTPURLConnection alloc] initWithRequest:theRequest
delegate:self
requestType:MGTwitterImageRequest
responseType:MGTwitterImage];

if (!connection) {
return nil;
} else {
[_connections setObject:connection forKey:[connection identifier]];
[connection release];
}

return [connection identifier];
}

#pragma mark Request sending methods

#define SET_AUTHORIZATION_IN_HEADER 1

- (NSString *)_sendRequestWithMethod:(NSString *)method
path:(NSString *)path
queryParameters:(NSDictionary *)params
body:(NSString *)body
requestType:(MGTwitterRequestType)requestType
responseType:(MGTwitterResponseType)responseType
{
// Construct appropriate URL string.
NSString *fullPath = path;
if (params) {
fullPath = [self _queryStringWithBase:fullPath parameters:params prefixed:YES];
}

#if SET_AUTHORIZATION_IN_HEADER
NSString *urlString = [NSString stringWithFormat:@"%@://%@/%@",
(_secureConnection) ? @"https" : @"http",
_APIDomain, fullPath];
#else
NSString *urlString = [NSString stringWithFormat:@"%@://%@:%@@%@/%@",
(_secureConnection) ? @"https" : @"http",
[self _encodeString:_username], [self _encodeString:_password],
_APIDomain, fullPath];
#endif

NSURL *finalURL = [NSURL URLWithString:urlString];
NSLog(@"finalURL: %@", finalURL);
if (!finalURL) {
return nil;
}

// Construct an NSMutableURLRequest for the URL and set appropriate request method.
NSMutableURLRequest *theRequest = [NSMutableURLRequest requestWithURL:finalURL
cachePolicy:NSURLRequestReloadIgnoringCacheData
timeoutInterval:URL_REQUEST_TIMEOUT];
if (method) {
[theRequest setHTTPMethod:method];
}
[theRequest setHTTPShouldHandleCookies:NO];

// Set headers for client information, for tracking purposes at Twitter.
[theRequest setValue:_clientName forHTTPHeaderField:@"X-Twitter-Client"];
[theRequest setValue:_clientVersion forHTTPHeaderField:@"X-Twitter-Client-Version"];
[theRequest setValue:_clientURL forHTTPHeaderField:@"X-Twitter-Client-URL"];

#if SET_AUTHORIZATION_IN_HEADER
if ([self username] && [self password]) {
// Set header for HTTP Basic authentication explicitly, to avoid problems with proxies and other intermediaries
NSString *authStr = [NSString stringWithFormat:@"%@:%@", [self username], [self password]];
NSData *authData = [authStr dataUsingEncoding:NSASCIIStringEncoding];
NSString *authValue = [NSString stringWithFormat:@"Basic %@", [authData base64EncodingWithLineLength:80]];
[theRequest setValue:authValue forHTTPHeaderField:@"Authorization"];
}
#endif

// Set the request body if this is a POST request.
BOOL isPOST = (method && [method isEqualToString:HTTP_POST_METHOD]);
if (isPOST) {
// Set request body, if specified (hopefully so), with 'source' parameter if appropriate.
NSString *finalBody = @"";
if (body) {
finalBody = [finalBody stringByAppendingString:body];
}
if (_clientSourceToken) {
finalBody = [finalBody stringByAppendingString:[NSString stringWithFormat:@"%@source=%@",
(body) ? @"&" : @"?" ,
_clientSourceToken]];
}

if (finalBody) {
[theRequest setHTTPBody:[finalBody dataUsingEncoding:NSUTF8StringEncoding]];
}
}

// Create a connection using this request, with the default timeout and caching policy,
// and appropriate Twitter request and response types for parsing and error reporting.
MGTwitterHTTPURLConnection *connection;
connection = [[MGTwitterHTTPURLConnection alloc] initWithRequest:theRequest
delegate:self
requestType:requestType
responseType:responseType];

if (!connection) {
return nil;
} else {
[_connections setObject:connection forKey:[connection identifier]];
[connection release];
}

return [connection identifier];
}

#pragma mark Parsing methods

- (void)_parseXMLForConnection:(MGTwitterHTTPURLConnection *)connection
{
NSString *identifier = [[[connection identifier] copy] autorelease];
NSData *xmlData = [[[connection data] copy] autorelease];
MGTwitterRequestType requestType = [connection requestType];
MGTwitterResponseType responseType = [connection responseType];

#if USE_LIBXML
NSURL *URL = [connection URL];

switch (responseType) {
case MGTwitterStatuses:
case MGTwitterStatus:
[MGTwitterStatusesLibXMLParser parserWithXML:xmlData delegate:self
connectionIdentifier:identifier requestType:requestType
responseType:responseType URL:URL];
break;
case MGTwitterUsers:
case MGTwitterUser:
[MGTwitterUsersLibXMLParser parserWithXML:xmlData delegate:self
connectionIdentifier:identifier requestType:requestType
responseType:responseType URL:URL];
break;
case MGTwitterDirectMessages:
case MGTwitterDirectMessage:
[MGTwitterMessagesLibXMLParser parserWithXML:xmlData delegate:self
connectionIdentifier:identifier requestType:requestType
responseType:responseType URL:URL];
break;
case MGTwitterMiscellaneous:
[MGTwitterMiscLibXMLParser parserWithXML:xmlData delegate:self
connectionIdentifier:identifier requestType:requestType
responseType:responseType URL:URL];
break;
default:
break;
}
#else
// Determine which type of parser to use.
switch (responseType) {
case MGTwitterStatuses:
case MGTwitterStatus:
[MGTwitterStatusesParser parserWithXML:xmlData delegate:self
connectionIdentifier:identifier requestType:requestType
responseType:responseType];
break;
case MGTwitterUsers:
case MGTwitterUser:
[MGTwitterUsersParser parserWithXML:xmlData delegate:self
connectionIdentifier:identifier requestType:requestType
responseType:responseType];
break;
case MGTwitterDirectMessages:
case MGTwitterDirectMessage:
[MGTwitterMessagesParser parserWithXML:xmlData delegate:self
connectionIdentifier:identifier requestType:requestType
responseType:responseType];
break;
case MGTwitterMiscellaneous:
[MGTwitterMiscParser parserWithXML:xmlData delegate:self
connectionIdentifier:identifier requestType:requestType
responseType:responseType];
break;
default:
break;
}
#endif
}

#pragma mark Delegate methods

- (BOOL) _isValidDelegateForSelector:(SEL)selector
{
return ((_delegate != nil) && [_delegate respondsToSelector:selector]);
}

#pragma mark MGTwitterParserDelegate methods

- (void)parsingSucceededForRequest:(NSString *)identifier
ofResponseType:(MGTwitterResponseType)responseType
withParsedObjects:(NSArray *)parsedObjects
{
// Forward appropriate message to _delegate, depending on responseType.
switch (responseType) {
case MGTwitterStatuses:
case MGTwitterStatus:
if ([self _isValidDelegateForSelector:@selector(statusesReceived:forRequest:)])
[_delegate statusesReceived:parsedObjects forRequest:identifier];
break;
case MGTwitterUsers:
case MGTwitterUser:
if ([self _isValidDelegateForSelector:@selector(userInfoReceived:forRequest:)])
[_delegate userInfoReceived:parsedObjects forRequest:identifier];
break;
case MGTwitterDirectMessages:
case MGTwitterDirectMessage:
if ([self _isValidDelegateForSelector:@selector(directMessagesReceived:forRequest:)])
[_delegate directMessagesReceived:parsedObjects forRequest:identifier];
break;
case MGTwitterMiscellaneous:
if ([self _isValidDelegateForSelector:@selector(miscInfoReceived:forRequest:)])
[_delegate miscInfoReceived:parsedObjects forRequest:identifier];
break;
default:
break;
}
}

- (void)parsingFailedForRequest:(NSString *)requestIdentifier
ofResponseType:(MGTwitterResponseType)responseType
withError:(NSError *)error
{
if ([self _isValidDelegateForSelector:@selector(requestFailed:withError:)])
[_delegate requestFailed:requestIdentifier withError:error];
}

#pragma mark NSURLConnection delegate methods

- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge
{
if ([challenge previousFailureCount] == 0 && ![challenge proposedCredential]) {
NSURLCredential *credential = [NSURLCredential credentialWithUser:_username password:_password
persistence:NSURLCredentialPersistenceForSession];
[[challenge sender] useCredential:credential forAuthenticationChallenge:challenge];
} else {
[[challenge sender] continueWithoutCredentialForAuthenticationChallenge:challenge];
}
}

- (void)connection:(MGTwitterHTTPURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
// This method is called when the server has determined that it has enough information to create the NSURLResponse.
// it can be called multiple times, for example in the case of a redirect, so each time we reset the data.
[connection resetDataLength];

// Get response code.
NSHTTPURLResponse *resp = (NSHTTPURLResponse *)response;
int statusCode = [resp statusCode];

if (statusCode >= 400) {
// Assume failure, and report to delegate.
NSError *error = [NSError errorWithDomain:@"HTTP" code:statusCode userInfo:nil];
if ([self _isValidDelegateForSelector:@selector(requestFailed:withError:)])
[_delegate requestFailed:[connection identifier] withError:error];

// Destroy the connection.
[connection cancel];
[_connections removeObjectForKey:[connection identifier]];

} else if (statusCode == 304 || [connection responseType] == MGTwitterGeneric) {
// Not modified, or generic success.
if ([self _isValidDelegateForSelector:@selector(requestSucceeded:)])
[_delegate requestSucceeded:[connection identifier]];
if (statusCode == 304) {
[self parsingSucceededForRequest:[connection identifier]
ofResponseType:[connection responseType]
withParsedObjects:[NSArray array]];
}

// Destroy the connection.
[connection cancel];
[_connections removeObjectForKey:[connection identifier]];
}

if (NO) {
// Display headers for debugging.
NSHTTPURLResponse *resp = (NSHTTPURLResponse *)response;
NSLog(@"(%d) [%@]:\r%@",
[resp statusCode],
[NSHTTPURLResponse localizedStringForStatusCode:[resp statusCode]],
[resp allHeaderFields]);
}
}

- (void)connection:(MGTwitterHTTPURLConnection *)connection didReceiveData:(NSData *)data
{
// Append the new data to the receivedData.
[connection appendData:data];
}

- (void)connection:(MGTwitterHTTPURLConnection *)connection didFailWithError:(NSError *)error
{
// Inform delegate.
if ([self _isValidDelegateForSelector:@selector(requestFailed:withError:)])
[_delegate requestFailed:[connection identifier] withError:error];

// Release the connection.
[_connections removeObjectForKey:[connection identifier]];
}

- (void)connectionDidFinishLoading:(MGTwitterHTTPURLConnection *)connection
{
// Inform delegate.
if ([self _isValidDelegateForSelector:@selector(requestSucceeded:)])
[_delegate requestSucceeded:[connection identifier]];

NSData *receivedData = [connection data];
if (receivedData) {
if (NO) {
// Dump data as string for debugging.
NSString *dataString = [NSString stringWithUTF8String:[receivedData bytes]];
NSLog(@"Succeeded! Received %d bytes of data:\r\r%@", [receivedData length], dataString);
}

if (NO) {
// Dump XML to file for debugging.
NSString *dataString = [NSString stringWithUTF8String:[receivedData bytes]];
[dataString writeToFile:[@"~/Desktop/twitter_messages.xml" stringByExpandingTildeInPath]
atomically:NO encoding:NSUnicodeStringEncoding error:NULL];
}

if ([connection responseType] == MGTwitterImage) {
// Create image from data.
#if TARGET_OS_IPHONE
UIImage *image = [[[UIImage alloc] initWithData:[connection data]] autorelease];
#else
NSImage *image = [[[NSImage alloc] initWithData:[connection data]] autorelease];
#endif

// Inform delegate.
if ([self _isValidDelegateForSelector:@selector(imageReceived:forRequest:)])
[_delegate imageReceived:image forRequest:[connection identifier]];
} else {
// Parse XML appropriately.
[self _parseXMLForConnection:connection];
}
}

// Release the connection.
[_connections removeObjectForKey:[connection identifier]];
}

#pragma mark -
#pragma mark Twitter API methods
#pragma mark -

#pragma mark Account methods

- (NSString *)checkUserCredentials
{
NSString *path = @"account/verify_credentials.xml";

return [self _sendRequestWithMethod:nil path:path queryParameters:nil body:nil
requestType:MGTwitterAccountRequest
responseType:MGTwitterGeneric];
}

- (NSString *)endUserSession
{
NSString *path = @"account/end_session"; // deliberately no format specified

return [self _sendRequestWithMethod:nil path:path queryParameters:nil body:nil
requestType:MGTwitterAccountRequest
responseType:MGTwitterGeneric];
}

- (NSString *)enableUpdatesFor:(NSString *)username
{
// i.e. follow
if (!username) {
return nil;
}
NSString *path = [NSString stringWithFormat:@"friendships/create/%@.xml", username];

return [self _sendRequestWithMethod:HTTP_POST_METHOD path:path queryParameters:nil body:nil
requestType:MGTwitterAccountRequest
responseType:MGTwitterUser];
}

- (NSString *)disableUpdatesFor:(NSString *)username
{
// i.e. no longer follow
if (!username) {
return nil;
}
NSString *path = [NSString stringWithFormat:@"friendships/destroy/%@.xml", username];

return [self _sendRequestWithMethod:HTTP_POST_METHOD path:path queryParameters:nil body:nil
requestType:MGTwitterAccountRequest
responseType:MGTwitterUser];
}

- (NSString *)isUser:(NSString *)username1 receivingUpdatesFor:(NSString *)username2
{
if (!username1 || !username2) {
return nil;
}
NSMutableDictionary *params = [NSMutableDictionary dictionaryWithCapacity:0];
[params setObject:username1 forKey:@"user_a"];
[params setObject:username2 forKey:@"user_b"];

NSString *path = @"friendships/exists.xml";

return [self _sendRequestWithMethod:nil path:path queryParameters:params body:nil
requestType:MGTwitterAccountRequest
responseType:MGTwitterMiscellaneous];
}

- (NSString *)enableNotificationsFor:(NSString *)username
{
if (!username) {
return nil;
}
NSString *path = [NSString stringWithFormat:@"notifications/follow/%@.xml", username];

return [self _sendRequestWithMethod:HTTP_POST_METHOD path:path queryParameters:nil body:nil
requestType:MGTwitterAccountRequest
responseType:MGTwitterUser];
}

- (NSString *)disableNotificationsFor:(NSString *)username
{
if (!username) {
return nil;
}
NSString *path = [NSString stringWithFormat:@"notifications/leave/%@.xml", username];

return [self _sendRequestWithMethod:HTTP_POST_METHOD path:path queryParameters:nil body:nil
requestType:MGTwitterAccountRequest
responseType:MGTwitterUser];
}

- (NSString *)getRateLimitStatus
{
NSString *path = @"account/rate_limit_status.xml";

return [self _sendRequestWithMethod:nil path:path queryParameters:nil body:nil
requestType:MGTwitterAccountRequest
responseType:MGTwitterMiscellaneous];
}

- (NSString *)setLocation:(NSString *)location
{
if (!location) {
return nil;
}

NSString *path = @"account/update_location.xml";

NSString *trimmedText = location;
if ([trimmedText length] > MAX_LOCATION_LENGTH) {
trimmedText = [trimmedText substringToIndex:MAX_LOCATION_LENGTH];
}

NSMutableDictionary *params = [NSMutableDictionary dictionaryWithCapacity:0];
[params setObject:trimmedText forKey:@"location"];
NSString *body = [self _queryStringWithBase:nil parameters:params prefixed:NO];

return [self _sendRequestWithMethod:HTTP_POST_METHOD path:path
queryParameters:params body:body
requestType:MGTwitterAccountRequest
responseType:MGTwitterGeneric];
}

- (NSString *)setNotificationsDeliveryMethod:(NSString *)method
{
NSString *deliveryMethod = method;
if (!method || [method length] == 0) {
deliveryMethod = @"none";
}

NSString *path = @"account/update_delivery_device.xml";

NSMutableDictionary *params = [NSMutableDictionary dictionaryWithCapacity:0];
if (deliveryMethod) {
[params setObject:deliveryMethod forKey:@"device"];
}

return [self _sendRequestWithMethod:HTTP_POST_METHOD path:path queryParameters:params body:nil
requestType:MGTwitterAccountRequest
responseType:MGTwitterGeneric];
}

- (NSString *)block:(NSString *)username
{
if (!username) {
return nil;
}

NSString *path = [NSString stringWithFormat:@"blocks/create/%@.xml", username];

return [self _sendRequestWithMethod:HTTP_POST_METHOD path:path queryParameters:nil body:nil
requestType:MGTwitterAccountRequest
responseType:MGTwitterUser];
}

- (NSString *)unblock:(NSString *)username
{
if (!username) {
return nil;
}

NSString *path = [NSString stringWithFormat:@"blocks/destroy/%@.xml", username];

return [self _sendRequestWithMethod:HTTP_POST_METHOD path:path queryParameters:nil body:nil
requestType:MGTwitterAccountRequest
responseType:MGTwitterUser];
}

- (NSString *)testService
{
NSString *path = @"help/test.xml";

return [self _sendRequestWithMethod:nil path:path queryParameters:nil body:nil
requestType:MGTwitterAccountRequest
responseType:MGTwitterGeneric];
}

- (NSString *)getDowntimeSchedule
{
NSString *path = @"help/downtime_schedule.xml";

return [self _sendRequestWithMethod:nil path:path queryParameters:nil body:nil
requestType:MGTwitterAccountRequest
responseType:MGTwitterMiscellaneous];
}

#pragma mark Retrieving updates

- (NSString *)getFollowedTimelineFor:(NSString *)username since:(NSDate *)date startingAtPage:(int)pageNum
{
// Included for backwards-compatibility.
return [self getFollowedTimelineFor:username since:date startingAtPage:pageNum count:0]; // zero means default
}

- (NSString *)getFollowedTimelineFor:(NSString *)username since:(NSDate *)date startingAtPage:(int)pageNum count:(int)count
{
NSString *path = @"statuses/friends_timeline.xml";

NSMutableDictionary *params = [NSMutableDictionary dictionaryWithCapacity:0];
if (date) {
[params setObject:[self _dateToHTTP:date] forKey:@"since"];
}
if (pageNum > 0) {
[params setObject:[NSString stringWithFormat:@"%d", pageNum] forKey:@"page"];
}
if (username) {
path = [NSString stringWithFormat:@"statuses/friends_timeline/%@.xml", username];
}
int tweetCount = DEFAULT_TWEET_COUNT;
if (count > 0) {
tweetCount = count;
}
[params setObject:[NSString stringWithFormat:@"%d", tweetCount] forKey:@"count"];

return [self _sendRequestWithMethod:nil path:path queryParameters:params body:nil
requestType:MGTwitterStatusesRequest
responseType:MGTwitterStatuses];
}

- (NSString *)getFollowedTimelineFor:(NSString *)username sinceID:(long long int)updateID startingAtPage:(int)pageNum count:(int)count
{
NSString *path = @"statuses/friends_timeline.xml";

NSMutableDictionary *params = [NSMutableDictionary dictionaryWithCapacity:0];
if (updateID > 0) {
[params setObject:[NSString stringWithFormat:@"%lld", updateID] forKey:@"since_id"];
}
if (pageNum > 0) {
[params setObject:[NSString stringWithFormat:@"%d", pageNum] forKey:@"page"];
}
if (username) {
path = [NSString stringWithFormat:@"statuses/friends_timeline/%@.xml", username];
}
int tweetCount = DEFAULT_TWEET_COUNT;
if (count > 0) {
tweetCount = count;
}
[params setObject:[NSString stringWithFormat:@"%d", tweetCount] forKey:@"count"];

return [self _sendRequestWithMethod:nil path:path queryParameters:params body:nil
requestType:MGTwitterStatusesRequest
responseType:MGTwitterStatuses];
}

- (NSString *)getUserTimelineFor:(NSString *)username since:(NSDate *)date count:(int)numUpdates
{
// Included for backwards-compatibility.
return [self getUserTimelineFor:username since:date startingAtPage:0 count:numUpdates];
}

- (NSString *)getUserTimelineFor:(NSString *)username since:(NSDate *)date startingAtPage:(int)pageNum count:(int)numUpdates
{
NSString *path = @"statuses/user_timeline.xml";

NSMutableDictionary *params = [NSMutableDictionary dictionaryWithCapacity:0];
if (date) {
[params setObject:[self _dateToHTTP:date] forKey:@"since"];
}
if (pageNum > 0) {
[params setObject:[NSString stringWithFormat:@"%d", pageNum] forKey:@"page"];
}
if (numUpdates > 0) {
[params setObject:[NSString stringWithFormat:@"%d", numUpdates] forKey:@"count"];
}
if (username) {
path = [NSString stringWithFormat:@"statuses/user_timeline/%@.xml", username];
}

return [self _sendRequestWithMethod:nil path:path queryParameters:params body:nil
requestType:MGTwitterStatusesRequest
responseType:MGTwitterStatuses];
}

- (NSString *)getUserTimelineFor:(NSString *)username sinceID:(long long int)updateID startingAtPage:(int)pageNum count:(int)numUpdates
{
NSString *path = @"statuses/user_timeline.xml";

NSMutableDictionary *params = [NSMutableDictionary dictionaryWithCapacity:0];
if (updateID > 0) {
[params setObject:[NSString stringWithFormat:@"%lld", updateID] forKey:@"since_id"];
}
if (pageNum > 0) {
[params setObject:[NSString stringWithFormat:@"%d", pageNum] forKey:@"page"];
}
if (numUpdates > 0) {
[params setObject:[NSString stringWithFormat:@"%d", numUpdates] forKey:@"count"];
}
if (username) {
path = [NSString stringWithFormat:@"statuses/user_timeline/%@.xml", username];
}

return [self _sendRequestWithMethod:nil path:path queryParameters:params body:nil
requestType:MGTwitterStatusesRequest
responseType:MGTwitterStatuses];
}

- (NSString *)getUserUpdatesArchiveStartingAtPage:(int)pageNum
{
NSString *path = @"account/archive.xml";

NSMutableDictionary *params = [NSMutableDictionary dictionaryWithCapacity:0];
if (pageNum > 0) {
[params setObject:[NSString stringWithFormat:@"%d", pageNum] forKey:@"page"];
}

return [self _sendRequestWithMethod:nil path:path queryParameters:params body:nil
requestType:MGTwitterStatusesRequest
responseType:MGTwitterStatuses];
}

- (NSString *)getPublicTimelineSinceID:(long long int)updateID
{
NSString *path = @"statuses/public_timeline.xml";

NSMutableDictionary *params = [NSMutableDictionary dictionaryWithCapacity:0];
if (updateID > 0) {
[params setObject:[NSString stringWithFormat:@"%lld", updateID] forKey:@"since_id"];
}

return [self _sendRequestWithMethod:nil path:path queryParameters:params body:nil
requestType:MGTwitterStatusesRequest
responseType:MGTwitterStatuses];
}

- (NSString *)getRepliesStartingAtPage:(int)pageNum
{
NSString *path = @"statuses/replies.xml";

NSMutableDictionary *params = [NSMutableDictionary dictionaryWithCapacity:0];
if (pageNum > 0) {
[params setObject:[NSString stringWithFormat:@"%d", pageNum] forKey:@"page"];
}

return [self _sendRequestWithMethod:nil path:path queryParameters:params body:nil
requestType:MGTwitterRepliesRequest
responseType:MGTwitterStatuses];
}

- (NSString *)getFavoriteUpdatesFor:(NSString *)username startingAtPage:(int)pageNum
{
NSString *path = @"favorites.xml";

NSMutableDictionary *params = [NSMutableDictionary dictionaryWithCapacity:0];
if (pageNum > 0) {
[params setObject:[NSString stringWithFormat:@"%d", pageNum] forKey:@"page"];
}
if (username) {
path = [NSString stringWithFormat:@"favorites/%@.xml", username];
}

return [self _sendRequestWithMethod:nil path:path queryParameters:params body:nil
requestType:MGTwitterStatusesRequest
responseType:MGTwitterStatuses];
}

- (NSString *)getUpdate:(long long int)updateID
{
NSString *path = [NSString stringWithFormat:@"statuses/show/%lld.xml", updateID];

return [self _sendRequestWithMethod:nil path:path queryParameters:nil body:nil
requestType:MGTwitterStatusesRequest
responseType:MGTwitterStatus];
}

#pragma mark Retrieving direct messages

- (NSString *)getDirectMessagesSince:(NSDate *)date startingAtPage:(int)pageNum
{
NSString *path = @"direct_messages.xml";

NSMutableDictionary *params = [NSMutableDictionary dictionaryWithCapacity:0];
if (date) {
[params setObject:[self _dateToHTTP:date] forKey:@"since"];
}
if (pageNum > 0) {
[params setObject:[NSString stringWithFormat:@"%d", pageNum] forKey:@"page"];
}

return [self _sendRequestWithMethod:nil path:path queryParameters:params body:nil
requestType:MGTwitterDirectMessagesRequest
responseType:MGTwitterDirectMessages];
}

- (NSString *)getDirectMessagesSinceID:(long long int)updateID startingAtPage:(int)pageNum
{
NSString *path = @"direct_messages.xml";

NSMutableDictionary *params = [NSMutableDictionary dictionaryWithCapacity:0];
if (updateID > 0) {
[params setObject:[NSString stringWithFormat:@"%lld", updateID] forKey:@"since_id"];
}
if (pageNum > 0) {
[params setObject:[NSString stringWithFormat:@"%d", pageNum] forKey:@"page"];
}

return [self _sendRequestWithMethod:nil path:path queryParameters:params body:nil
requestType:MGTwitterDirectMessagesRequest
responseType:MGTwitterDirectMessages];
}

- (NSString *)getSentDirectMessagesSince:(NSDate *)date startingAtPage:(int)pageNum
{
NSString *path = @"direct_messages/sent.xml";

NSMutableDictionary *params = [NSMutableDictionary dictionaryWithCapacity:0];
if (date) {
[params setObject:[self _dateToHTTP:date] forKey:@"since"];
}
if (pageNum > 0) {
[params setObject:[NSString stringWithFormat:@"%d", pageNum] forKey:@"page"];
}

return [self _sendRequestWithMethod:nil path:path queryParameters:params body:nil
requestType:MGTwitterDirectMessagesRequest
responseType:MGTwitterDirectMessages];
}

- (NSString *)getSentDirectMessagesSinceID:(long long int)updateID startingAtPage:(int)pageNum
{
NSString *path = @"direct_messages/sent.xml";

NSMutableDictionary *params = [NSMutableDictionary dictionaryWithCapacity:0];
if (updateID > 0) {
[params setObject:[NSString stringWithFormat:@"%lld", updateID] forKey:@"since_id"];
}
if (pageNum > 0) {
[params setObject:[NSString stringWithFormat:@"%d", pageNum] forKey:@"page"];
}

return [self _sendRequestWithMethod:nil path:path queryParameters:params body:nil
requestType:MGTwitterDirectMessagesRequest
responseType:MGTwitterDirectMessages];
}

#pragma mark Retrieving user information

- (NSString *)getUserInformationFor:(NSString *)username
{
if (!username) {
return nil;
}
NSString *path = [NSString stringWithFormat:@"users/show/%@.xml", username];

return [self _sendRequestWithMethod:nil path:path queryParameters:nil body:nil
requestType:MGTwitterUserInfoRequest
responseType:MGTwitterUser];
}

- (NSString *)getUserInformationForEmail:(NSString *)email
{
NSString *path = @"users/show.xml";
NSMutableDictionary *params = [NSMutableDictionary dictionaryWithCapacity:0];
if (email) {
[params setObject:email forKey:@"email"];
} else {
return nil;
}

return [self _sendRequestWithMethod:nil path:path queryParameters:params body:nil
requestType:MGTwitterUserInfoRequest
responseType:MGTwitterUser];
}

- (NSString *)getRecentlyUpdatedFriendsFor:(NSString *)username startingAtPage:(int)pageNum
{
NSString *path = @"statuses/friends.xml";

NSMutableDictionary *params = [NSMutableDictionary dictionaryWithCapacity:0];
if (username) {
path = [NSString stringWithFormat:@"statuses/friends/%@.xml", username];
}
if (pageNum > 0) {
[params setObject:[NSString stringWithFormat:@"%d", pageNum] forKey:@"page"];
}

return [self _sendRequestWithMethod:nil path:path queryParameters:params body:nil
requestType:MGTwitterUserInfoRequest
responseType:MGTwitterUsers];
}

- (NSString *)getFollowersIncludingCurrentStatus:(BOOL)flag
{
NSString *path = @"statuses/followers.xml";

NSMutableDictionary *params = [NSMutableDictionary dictionaryWithCapacity:0];
if (!flag) {
[params setObject:@"true" forKey:@"lite"]; // slightly bizarre, but correct.
}

return [self _sendRequestWithMethod:nil path:path queryParameters:params body:nil
requestType:MGTwitterUserInfoRequest
responseType:MGTwitterUsers];
}

- (NSString *)getFeaturedUsers
{
NSString *path = @"statuses/featured.xml";

return [self _sendRequestWithMethod:nil path:path queryParameters:nil body:nil
requestType:MGTwitterUserInfoRequest
responseType:MGTwitterUsers];
}

#pragma mark Sending and editing updates

- (NSString *)sendUpdate:(NSString *)status
{
return [self sendUpdate:status inReplyTo:0];
}

- (NSString *)sendUpdate:(NSString *)status inReplyTo:(long long int)updateID
{
if (!status) {
return nil;
}

NSString *path = @"statuses/update.xml";

NSString *trimmedText = status;
if ([trimmedText length] > MAX_MESSAGE_LENGTH) {
trimmedText = [trimmedText substringToIndex:MAX_MESSAGE_LENGTH];
}

NSMutableDictionary *params = [NSMutableDictionary dictionaryWithCapacity:0];
[params setObject:trimmedText forKey:@"status"];
if (updateID > 0) {
[params setObject:[NSString stringWithFormat:@"%lld", updateID] forKey:@"in_reply_to_status_id"];
}
NSString *body = [self _queryStringWithBase:nil parameters:params prefixed:NO];

return [self _sendRequestWithMethod:HTTP_POST_METHOD path:path
queryParameters:params body:body
requestType:MGTwitterStatusSend
responseType:MGTwitterStatus];
}

- (NSString *)deleteUpdate:(long long int)updateID
{
NSString *path = [NSString stringWithFormat:@"statuses/destroy/%lld.xml", updateID];

return [self _sendRequestWithMethod:HTTP_POST_METHOD path:path queryParameters:nil body:nil
requestType:MGTwitterAccountRequest
responseType:MGTwitterGeneric];
}

- (NSString *)markUpdate:(long long int)updateID asFavorite:(BOOL)flag
{
NSString *path = [NSString stringWithFormat:@"favorites/%@/%lld.xml",
(flag) ? @"create" : @"destroy" ,
updateID];

return [self _sendRequestWithMethod:HTTP_POST_METHOD path:path queryParameters:nil body:nil
requestType:MGTwitterAccountRequest
responseType:MGTwitterStatus];
}

#pragma mark Sending and editing direct messages

- (NSString *)sendDirectMessage:(NSString *)message to:(NSString *)username
{
if (!message || !username) {
return nil;
}

NSString *path = @"direct_messages/new.xml";

NSString *trimmedText = message;
if ([trimmedText length] > MAX_MESSAGE_LENGTH) {
trimmedText = [trimmedText substringToIndex:MAX_MESSAGE_LENGTH];
}

NSMutableDictionary *params = [NSMutableDictionary dictionaryWithCapacity:0];
[params setObject:trimmedText forKey:@"text"];
[params setObject:username forKey:@"user"];
NSString *body = [self _queryStringWithBase:nil parameters:params prefixed:NO];

return [self _sendRequestWithMethod:HTTP_POST_METHOD path:path
queryParameters:params body:body
requestType:MGTwitterDirectMessageSend
responseType:MGTwitterDirectMessage];
}

- (NSString *)deleteDirectMessage:(long long int)updateID
{
NSString *path = [NSString stringWithFormat:@"direct_messages/destroy/%lld.xml", updateID];

return [self _sendRequestWithMethod:HTTP_POST_METHOD path:path queryParameters:nil body:nil
requestType:MGTwitterAccountRequest
responseType:MGTwitterGeneric];
}

@end

See the gist on GitHub