Best way to map subrequest without manual add/remove

[k06a]

I am using request to get places:

http://.../api/json/GetPlaces

Then I need to make request:

http://.../api/json/GetPlaceMenu?place_id=%@

I am doing this way:

NSArray *places = [FEMManagedObjectDeserializer deserializeCollectionExternalRepresentation:responseJSON usingMapping:[Place mapping] context:[NSManagedObjectContext MR_defaultContext]];

For each place I am doing request and mapping like this this:

NSArray *menus_arr = [FEMManagedObjectDeserializer deserializeCollectionExternalRepresentation:responseJSON usingMapping:[Menu mapping] context:[NSManagedObjectContext MR_defaultContext]];
NSSet *menus = [NSSet setWithArray:menus_arr];

And then I am trying to determine menus to add and to remove from place objects:

NSMutableSet *menusToAdd = [NSMutableSet set];
for (Menu *menu in menus) {
    if ([place.menus objectsPassingTest:^BOOL(Menu *obj, BOOL *stop) { return [obj.menu_id isEqual:menu.menu_id]; }].count == 0)
        [menusToAdd addObject:menu];
}
NSMutableSet *menusToRemove = [NSMutableSet set];
for (Menu *menu in place.menus) {
    if ([menus objectsPassingTest:^BOOL(Menu *obj, BOOL *stop) { return [obj.menu_id isEqual:menu.menu_id]; }].count == 0)
        [menusToRemove addObject:menu];
}

[place addMenus:menusToAdd];
[place removeMenus:menusToRemove];

Really I don't wanna use this code :) I wanna Fast and Easy Mapping. Please tell me how to avoid this code with FAM.

[dimazen]

@k06a basically all you need is to "replace" old menus by new one with reuse of existing? Am i right?

In this case this code should help you:

FEMManagedObjectMapping *placeMapping = ...;
FEMManagedObjectMapping *menuMapping = ...;

FEMRelationship *menuRelationship = [[FEMRelationship alloc] initWithProperty:@"menuRelationshipPropertyNameForPlace" keyPath:@"keyPathForMenusInJSON" assignmentPolicy:FEMAssignmentPolicyCollectionReplace objectMapping:menuMapping];

[placeMapping addRelationship:menuRelationship];

[dimazen]

@k06a
Also does http://.../api/json/GetPlaceMenu?place_id=%@ contain identifier of place or just nested menus?

[k06a]

@dimazen, Menu json does not contains parent place_id.

[dimazen]

@k06a ok, in this way you probably need something like that:

EMManagedObjectMapping *placeMapping = empty mapping with entity name. ;
FEMManagedObjectMapping *menuMapping = real mapping of menu;

FEMRelationship *menuRelationship = [[FEMRelationship alloc] initWithProperty:@"menuRelationshipPropertyNameForPlace" keyPath:nil assignmentPolicy:FEMAssignmentPolicyCollectionReplace objectMapping:menuMapping];

[placeMapping addRelationship:menuRelationship];

After you're done with mapping execute this code

[FEMManagedObjectDeserializer fillObject:userPlace fromExternalRepresentation:dictionaryFromNetwork usingMapping:placeMapping];

[k06a]

@dimazen thanks!

[k06a]

@dimazen I am using deserializeCollectionExternalRepresentation and I am falling on NSAssert on FEMCache.m:94:

NSAssert(
    NO,
    @"Expected container classes: NSArray, NSDictionary. Got:%@",
    NSStringFromClass([representation class])
);

I found similar problem and similar solution here: #26 But it is not working for me.

[dimazen]

@k06a hm, can you share the JSON & mapping?