gistfile1.m

- (void)bindFormCell:(MYFormCell *)cell toViewModel:(MYFormViewModel *)viewModel withKeyPath:(NSString *)keyPath
{
    // signal passing in cell as an observer will complete the signal when cell is dealloced
    // (as well as (read "OR") when viewModel is dealloced)
    RACSignal *textInputSignal = [viewModel rac_valuesForKeyPath:keyPath observer:cell];
    @weakify(cell);
    RACDisposable *inputDisposable = [textInputSignal subscribeNext:^(NSString *text) {
        @strongify(cell);
        cell.textField.text = text;
    }];
    
    RACSignal *textOutputSignal = [cell.textField rac_textSignal];
    @weakify(viewModel);
    RACDisposable *outputDisposable = [textOutputSignal subscribeNext:^(NSString *text) {
        @strongify(viewModel);
        [viewModel setValue:text forKey:keyPath];
    }];
    
    // whenever the cell is reused unbind those signals
    [[[cell rac_prepareForReuseSignal] take:1] subscribeNext:^(id x) {
        [inputDisposable dispose];
        [outputDisposable dispose];
    }];
}