ios - What does 'array' method in RACSequence (ReactiveCocoa) do? -

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this code snippet ray wenderich's ios 7 best practices article. he's fetching json file , making model each in list;

return [[self fetchjsonfromurl:url] map:^id(nsdictionary *json) {                 racsequence *list = [json[@"list"] rac_sequence];                  return [[list map:^(nsdictionary *item) {                     return [mtljsonadapter modelofclass:[wxdailyforecase class] fromjsondictionary:item error:nil];                 }] array];     }];

what array do?

racsequence's instance method map returns racsequence instance. if want nsarray instance, have use -[racsequence array] method evaluate entire sequence , convert values nsarray.

by way, map method executed lazily; sequence produces values, receive them 1 one until unsubscribe or reach end of sequence. calling -array method block current thread if of values not yet available (until become available, @ point method un-block , return array).


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