ios - Blocking call in parse's queryfortable -

i have activity class, theme class , photo class. if there follow activity need find out theme user follows, photos tagged theme. here code:

pfquery *themequery = [pfquery querywithclassname:@"occasion"]; pfquery *followingactivitiesquery = [pfquery querywithclassname:kpapactivityclasskey];  [followingactivitiesquery wherekey:kpapactivityfromuserkey equalto:[pfuser currentuser]];  [followingactivitiesquery wherekey:@"type" equalto:@"followtheme"];  [followingactivitiesquery includekey:@"themepointer"];  nsarray *objects = [followingactivitiesquery findobjects];  (pfobject *object in objects) {    pfobject *tobject = object[@"themepointer"];    nsstring *themename = [tobject valueforkey:@"name"];    [themequery wherekey:@"name" equalto: themename]; }  pfquery *photosfromfollowedthemequery = [pfquery querywithclassname:self.parseclassname]; [photosfromfollowedthemequery wherekey:@"themerelation" matchesquery:themequery]; 

this code works findobjects blocking call app hangs bit while waiting. how rewrite query ?

instead of using findobjects, use findobjectsinbackgroundwithblock: executed asynchronously , not block main thread.

so code this:

pfquery *themequery = [pfquery querywithclassname:@"occasion"]; // ... add filters ... [themequery findobjectsinbackgroundwithblock:^(nsarray *results, nserror *error) {     nslog(@"results: %@", results); }]; 

[update] here additional sample code query, compiled in head might need tweaking.

pfquery *followingactivitiesquery = [pfquery querywithclassname:kpapactivityclasskey]; [followingactivitiesquery wherekey:kpapactivityfromuserkey equalto:[pfuser currentuser]];  [followingactivitiesquery wherekey:@"type" equalto:@"followtheme"];  [followingactivitiesquery includekey:@"themepointer"]; [followingactivitiesquery findobjectsinbackgroundwithblock:^(nsarray *results, nserror *error) {     pfquery *themequery = [pfquery querywithclassname:@"occasion"];     (pfobject *object in results) {        pfobject *tobject = object[@"themepointer"];        nsstring *themename = [tobject valueforkey:@"name"];        [themequery wherekey:@"name" equalto: themename];     }      pfquery *photosfromfollowedthemequery = [pfquery querywithclassname:self.parseclassname];     [photosfromfollowedthemequery wherekey:@"themerelation" matchesquery:themequery];     [photosfromfollowedthemequery findobjectsinbackgroundwithblock:^(nsarray *finalresults, nserror *finalerror) {         // final results     }]; }];