ios - Parse PFRelation complex search -

i'm building ios app parse has few complex queries , running trouble pfrelation.

it's social network website people submit articles. can follow other users , see articles submitted. can search based on topics.

this code have

pfquery* query = [pfquery querywithclassname:@"article"];  //remove articles user has seen or submitted [query wherekey:@"likedby" notequalto:currentuser]; //'likedby' relation [query wherekey:@"dislikedby" notequalto:currentuser]; //'dislikedby' relation [query wherekey:@"submittedby" notequalto:currentuser]; //'submittedby' relation  [query wherekey:@"tagarray" containedin:tags]; [query orderbydescending:@"createdat"];  pfrelation* relation = [currentuser relationforkey:@"following"]; //following relation user pfquery* followingquery = [relation query]; [followingquery findobjectsinbackgroundwithblock:^(nsarray* results, nserror* error) {      //results first query list of people user following      [query wherekey:@"submittedby" containedin:results]; //submitted relation on article     [query findobjectsinbackgroundwithblock:^(nsarray* results, nserror* error) {          /* return items match tags set above.         however, if there no tags, not articles         match "submittedby" above. empty */         completion(results);     }];  }]; } 

thank time reading this.

i able resolve issue creating subquery:

pfquery* query = [pfquery querywithclassname:@"article"];  //remove articles user has seen or submitted [query wherekey:@"likedby" notequalto:currentuser]; //'likedby' relation [query wherekey:@"dislikedby" notequalto:currentuser]; //'dislikedby' relation [query wherekey:@"submittedby" notequalto:currentuser]; //'submittedby' relation  [query wherekey:@"tagarray" containedin:tags];  // create array hold of queries nsmutablearray* queryarray = [nsmutablearray arraywithcapacity:10];  pfrelation* relation = [currentuser relationforkey:@"following"]; //following relation user pfquery* followingquery = [relation query]; [followingquery findobjectsinbackgroundwithblock:^(nsarray* results, nserror* error) {      //results first query list of people user following    (pfobject* user in results) {             //create new query each result , add query array                     pfquery* querysub = [pfquery querywithclassname:@"app"];                      [querysub wherekey:@"submittedby" equalto:user];                      [queryarray addobject:querysub];                 }                  //query of queries @ once                 pfquery* finalquery = [pfquery orquerywithsubqueries:queryarray];      [finalquery findobjectsinbackgroundwithblock:^(nsarray* results, nserror* error) {     //note: cannot sort via query subqueries, had sort results array when completed            …...     }];  }]; }