gistfile1.m

//
//  EventSource.m
//  Dailymotion
//
//  Created by Olivier Poitrey on 24/09/12.
//  Copyright (c) 2012 Dailymotion. All rights reserved.
//

#import "EventSource.h"

@interface EventSource ()

@property (strong, nonatomic, readwrite) NSURL *URL;
@property (strong, nonatomic) void (^_dataBlock)(NSString *data);
@property (strong, nonatomic) NSURLConnection *_connection;
@property (assign, nonatomic) BOOL _autoReconnect;

@end

@implementation EventSource

+ (EventSource *)eventSourceWithURL:(NSURL *)URL onData:(void (^)(NSString *data))dataBlock
{
    EventSource *eventSource = EventSource.new;
    eventSource.URL = URL;
    eventSource._dataBlock = dataBlock;
    [eventSource connect];
    return eventSource;
}

- (void)dealloc
{
    [self disconnect];
}

- (void)connect
{
    if (self._connection && self._autoReconnect) return;
    [self._connection cancel];
    self._autoReconnect = YES;
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:self.URL];
    [request setValue:@"text/event-stream" forHTTPHeaderField:@"Accept"];
    self._connection = [NSURLConnection connectionWithRequest:request delegate:self];
}

- (void)disconnect
{
    self._autoReconnect = NO;
    [self._connection cancel];
}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
    NSString *dataString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    for (NSString *line in [dataString componentsSeparatedByString:@"\n"])
    {
        if ([line isEqualToString:@""]) continue;
        if ([line hasPrefix:@"data:"])
        {
            self._dataBlock([[line substringFromIndex:5] stringByTrimmingCharactersInSet:NSCharacterSet.whitespaceCharacterSet]);
        }
        else
        {
            DDLogWarn(@"unparsed line: %@", line);
        }
    }
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    if (self._autoReconnect)
    {
        [self connect];
    }
}

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
    if (self._autoReconnect)
    {
        [self connect];
    }
}

@end