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iOS

Posted by Mehrbod Nikbakhsh
Mehrbod Nikbakhsh
293 Points

NSMutableArray - add data to specific object

I have two NSMutableArray in my project with name:

  • weeks
  • post

i receive the the data from back-end in JSON. { "posts":[ {"title" : "some title", "w" : "01"}, {"title" : "some title", "w" : "01"}, {"title" : "some title", "w" : "02"} ], "weeks":[ {"w":"01"}, {"w":"52"} ] }

I serialize it and with Dictionary get the data and put it into weeks and posts

How can I build a new NSMutableArray which have the weeks as a key/object and in that alla posts which belongs to it

like:

( 01 = ( {"title" : "some title", "w" : "01"}, {"title" : "some title", "w" : "01"} ), 02 = ( {"title" : "some title", "w" : "02""} ), )

I can do this in the Back-End .. wich I did in the beginning , but I got problem when I try to load more data into my table and update section & rows.

maybe other ways I can pars my posts into the my dynamic table view based on weeks !

thanks !

1 Answer

John W
John W
21,558 Points

Take a look at what you want, i.e. (01 = ( {"title"... etc, The outermost level is actually a dictionary, the next level is an array, then finally another dictionary, which is actually your "post" object.

So to construct what you want, you start with NSMutableDictionary, then hash the posts by their "w" element as follow:

NSMutableDictionary * postByWeek = [NSMutableDictionary dictionaryWithCapacity:0];
for ( NSDictionary * aPost in self.post ) {
   NSString * week = aPost[@"w"];
   if ( postByWeek[week] == nil ) { // a dictionary returns nil if the key is not present
       // initialize the new key with an empty NSMutableArray
       postByWeek[week] = [NSMutableArray arrayWithCapacity:1];
   }

  // Add the post to the dictionary
  [postByWeek[week] addObject:aPost]; 
}
Mehrbod Nikbakhsh
Mehrbod Nikbakhsh
293 Points

yes exactly. so perfect. I added the NSMutableDictionary to the .h file , and initialize it in viewDidLoad once ! i works very nice ;)

thanks a lot for your time, and clean code ;)