ios - Where does filterContentForSearchText:scope: method come from? -

recently, noticed filtercontentforsearchtext:scope: appeared in multiple tutorials regarding how implement search bar.

however, looked references of both uisearchdisplaydelegate , uisearchbardelegate. found filtercontentforsearchtext:scope: neither required nor optional method.

i wondered if filtercontentforsearchtext:scope: conventional method name filtering search results?

yes, convention common method called uisearchdisplaydelegate methods

- (bool)searchdisplaycontroller:(uisearchdisplaycontroller *)controller shouldreloadtableforsearchstring:(nsstring *)searchstring; - (bool)searchdisplaycontroller:(uisearchdisplaycontroller *)controller shouldreloadtableforsearchscope:(nsinteger)searchoption; 

the current "simple uisearchbar state restoration" sample project apple not use convention:

- (bool)searchdisplaycontroller:(uisearchdisplaycontroller *)controller shouldreloadtableforsearchstring:(nsstring *)searchstring {     nsstring *scope;      nsinteger selectedscopebuttonindex = [self.searchdisplaycontroller.searchbar selectedscopebuttonindex];     if (selectedscopebuttonindex > 0)     {         scope = [[aplproduct devicetypenames] objectatindex:(selectedscopebuttonindex - 1)];     }      [self updatefilteredcontentforproductname:searchstring type:scope];      // return yes cause search result table view reloaded.     return yes; }