I am parsing the needed links which is in the header of the response from the server. My header looks like
Access-Control-Allow-Origin → * Age → 0 Cache-Control → private,must-revalidate
Connection → keep-alive
Content-Encoding → gzip Content-Type → application/json
Date → Sat, 13 Jun 2015 15:58:56 GMT ETag → W/"cb38bb07f1635fd6aba5969985bf0607"
Link → http://thisIsCurrentlink&limit=24; rel="next",http://thisIsLastlink&limit=24; rel="last",http://thisIsFirstlink&limit=24; rel="first",<>; rel="prev"
Server → nginx
Vary → Accept-Encoding
X-Total-Count → 131
transfer-encoding → chunked
By doing this, I can get the links array which contains all links
NSString *linkHeader = [(NSHTTPURLResponse *)operation.response allHeaderFields][@"Link"];
NSArray *links = [linkHeader componentsSeparatedByString:@","];
Then I am doing the following to get all links I needed
RACSequence *sequence = [links.rac_sequence map:^id(NSString* item) {
NSError *error;
NSLog(@"item is %@",item);
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"<(.*)>" options:0 error:&error];
NSString *actualLink;
if (regex != nil) {
NSTextCheckingResult *result = [regex firstMatchInString:item
options:0
range:NSMakeRange(0, item.length)
];
if (result) {
NSRange range = [result rangeAtIndex:1];
actualLink = [item substringWithRange:range];
NSLog(@"actualLink is %@",actualLink);
return [RACSequence return:actualLink];
}
}
return [RACSequence empty];
}];
Right now sequence is containing all links which are
http://thisIsCurrentlink&limit=24
http://thisIsLastlink&limit=24
http://thisIsFirsttlink&limit=24
My question is how can I access each item from above sequence
Just use the array method, which converts RACSequence into an array.
Also, you don't need to use RACSequence return:, that's creating sequences within your sequence, just return the usual string and nil, then use a filter after the map to remove all nil values before trying to extract it as an array.
Example:
NSArray *actualLinks = [[links.rac_sequence map:^id(NSString* item) {
NSError *error = nil;
NSLog(@"item is %@",item);
NSRegularExpression *regex =
[NSRegularExpression regularExpressionWithPattern:@"<(.*)>" options:0 error:&error];
NSString *actualLink = nil;
if (regex != nil) {
NSTextCheckingResult *result = [regex firstMatchInString:item
options:0
range:NSMakeRange(0, item.length)];
if (result) {
NSRange range = [result rangeAtIndex:1];
actualLink = [item substringWithRange:range];
NSLog(@"actualLink is %@",actualLink);
}
}
return actualLink;
}] ignore:nil].array;