ios - Encode with coder not being called on lower level object -

i'm updating existing app follow mvc design. created top level data model class. in datamodel class archive , dearchive children array (self.children). array of child objects items property. items property array of babymilestone objects. both child class , babymilestone class take care of encode/decoding themselves. objects in child class being encoded , decoded. objects in babymilestone class not. encode coder not being called on babymilestone objects being called on child class.
question : need special encode array of objects property of else? debugging suggestions welcome!

the top level datamodel class handles saving , loading of .plist

@implementation datamodel -(id)init {     if ((self = [super init]))     {           [self loadbabymilestones];     }     return self; }  /////////////loading , saving methods//////////////// //path documentsdirectory loading , saving .plist file of babymilestone objects -(nsstring *)documentsdirectory {   nsarray *paths = nssearchpathfordirectoriesindomains(nsdocumentdirectory, nsuserdomainmask, yes);     nsstring *documentsdirectory = [paths firstobject];     return documentsdirectory; }  -(nsstring *)datafilepath {   return [[self documentsdirectory] stringbyappendingpathcomponent:@"babymilestones.plist"];     nslog(@"the documents directory %@", [self documentsdirectory]); }  //save babymilestoneitems .plist -(void) savebabymilestoneitems {     child *child;     child = [[child alloc] init];     child = [self.children objectatindex:0 ];     nslog(@"the length of children array in save method %lu", child.items.count);      nsmutabledata *data = [[nsmutabledata alloc] init];     nskeyedarchiver *archiver = [[nskeyedarchiver alloc] initforwritingwithmutabledata:data];     [archiver encodeobject:self.children forkey:@"children"];     [archiver finishencoding];     [data writetofile:[self datafilepath] atomically:yes];     nslog(@"in savebabymilestoneitems"); }  //loading babymilestones data .plist file -(void) loadbabymilestones {     nsstring *path = [self datafilepath];     nslog(@"data file path %@", [self datafilepath]);     if ([[nsfilemanager defaultmanager]fileexistsatpath:path])  //if file exists load self.children     {         nsdata *data = [[nsdata alloc] initwithcontentsoffile:path];         nskeyedunarchiver *unarchiver = [[nskeyedunarchiver alloc] initforreadingwithdata:data];         self.children = [unarchiver decodeobjectforkey:@"children"];         [unarchiver finishdecoding];         nslog(@"in loadbabymilestones loading file");      }     //default list     else {         self.children = [[nsmutablearray alloc]initwithcapacity:2];         child *child;         child = [[child alloc] init];         child.name = @"test child 1";         [self.children addobject:child];         child = [[child alloc]init];        child.name = @"test child 2";        [self.children addobject:child];        (child *child in self.children) {         babymilestone *babyitem;         babyitem = [[babymilestone alloc] init];         babyitem.text = @"arrives home";         babyitem.backgroundimagename = @"newtext_home";         babyitem.imagename = @"flat_home_icon.png";         babyitem.textdescription = nil;         babyitem.highresimage = @"newtext_homehighres.jpg";         babyitem.newitem = no;         babyitem.date = nil;         babyitem.nativeitem = yes;         babyitem.photoid = @-1;         [child.items addobject:babyitem];         }     } }  @end 

the babymilestone class (encodewithcoder never called)

#import "babymilestone.h" @implementation babymilestone  -(id)initwithcoder:(nscoder *)adecoder {     if ((self=[super init])) {         self.textdescription = [adecoder decodeobjectforkey:@"textdescription"];         self.text = [adecoder decodeobjectforkey:@"text"];         self.photoid = [adecoder decodeobjectforkey:@"photoid1"];         self.imagename = [adecoder decodeobjectforkey:@"thumbnail"];         self.date = [adecoder decodeobjectforkey:@"date"];         self.backgroundimagename = [adecoder decodeobjectforkey:@"backgroundimage"];         self.highresimage = [adecoder decodeobjectforkey:@"highresimage"];         self.nativeitem = [adecoder decodeboolforkey:@"nativeitem"];      }     return self; }  -(void) encodewithcoder:(nscoder *)acoder {     [acoder encodeobject:self.textdescription forkey:@"textdescription"];     [acoder encodeobject:self.text forkey:@"text"];     [acoder encodeobject:self.photoid forkey:@"photoid1"];     [acoder encodeobject:self.imagename forkey:@"thumbnail"];     [acoder encodeobject:self.date forkey:@"date"];     [acoder encodeobject:self.backgroundimagename forkey:@"backgroundimage"];     [acoder encodeobject:self.highresimage forkey: @"highresimage"];     [acoder encodebool:self.nativeitem forkey:@"nativeitem"];     nslog(@"in encode coder in babymilestone.m"); }  @end 

child class

#import "child.h"  @implementation child - (id)init {    //used when user add new child     if ((self = [super init])) {         self.items = [[nsmutablearray alloc] initwithcapacity:20];     }     return self; }  -(id)initwithcoder:(nscoder *)adecoder  //load existing children  {     if ((self=[super init])) {         self.name = [adecoder decodeobjectforkey:@"name"];         //self.birthday = [adecoder decodeobjectforkey:@"birthday"];         nslog(@"init coder being called on child class");      }     return self; }  -(void)encodewithcoder:(nscoder *)acoder {     [acoder encodeobject:self.name forkey:@"name"];     nslog(@"encodewithcoder called in child class");     //[acoder encodeobject:self.birthday forkey: @"birthday]; } @end 

your child objects, keepers of babymilestones, ones responsible encoding them. add [acoder encodeobject:self.items forkey:@"items"]; child's encodewithcoder:. way, when child told encode, encode babymilestones well.