Access Nested NSDictionary Items - ios

Question

I have this NSDictionary that i received from an api call:
{
items = (
{
accessInfo = {
accessViewStatus = SAMPLE;
country = US;
embeddable = 1;
epub = {
isAvailable = 0;
};
pdf = {
isAvailable = 0;
};
publicDomain = 0;
quoteSharingAllowed = 0;
textToSpeechPermission = ALLOWED;
viewability = PARTIAL;
webReaderLink = "http://books.google.com/books/reader?id=LdB2_WzYpKgC&hl=&printsec=frontcover&output=reader&source=gbs_api";
};
etag = 1xxAlevFUSc;
id = "LdB2_WzYpKgC";
kind = "books#volume";
saleInfo = {
country = US;
isEbook = 0;
saleability = "NOT_FOR_SALE";
};
searchInfo = {
textSnippet = "The saga of their daily exploits won cartoonist Bill Watterson the coveted Reuben Award for "Outstanding Cartoonist of the Year." Something Under the Bed Is Drooling is a jewel.";
};
selfLink = "https://www.googleapis.com/books/v1/volumes/LdB2_WzYpKgC";
volumeInfo = {
authors = (
"Bill Watterson"
);
averageRating = "4.5";
canonicalVolumeLink = "http://books.google.com/books/about/Something_Under_the_Bed_Is_Drooling.html?hl=&id=LdB2_WzYpKgC";
categories = (
Humor
);
contentVersion = "0.0.1.0.preview.1";
description = "\"Be good to yourself: Buy a copy of this Calvin and Hobbes cartoon book. If you don't laugh out loud at every third strip, check your pulse. You may be dead.\" --Phil Musick, Pittsburgh Press Calvin is a rambunctious six-year-old whose manic antics threaten world peace. Hobbes is his stuffed tiger who comes alive when adults aren\"t around. The saga of their daily exploits won cartoonist Bill Watterson the coveted Reuben Award for \"Outstanding Cartoonist of the Year.\" Something Under the Bed Is Drooling is a jewel.";
imageLinks = {
smallThumbnail = "http://bks8.books.google.com/books?id=LdB2_WzYpKgC&printsec=frontcover&img=1&zoom=5&edge=curl&source=gbs_api";
thumbnail = "http://bks8.books.google.com/books?id=LdB2_WzYpKgC&printsec=frontcover&img=1&zoom=1&edge=curl&source=gbs_api";
};
industryIdentifiers = (
{
identifier = 0836218256;
type = "ISBN_10";
},
{
identifier = 9780836218251;
type = "ISBN_13";
}
);
infoLink = "http://books.google.com/books?id=LdB2_WzYpKgC&dq=isbn:0836218256&hl=&source=gbs_api";
language = en;
pageCount = 127;
previewLink = "http://books.google.com/books?id=LdB2_WzYpKgC&printsec=frontcover&dq=isbn:0836218256&hl=&cd=1&source=gbs_api";
printType = BOOK;
publishedDate = "1988-01-01";
publisher = "Andrews McMeel Publishing";
ratingsCount = 18;
readingModes = {
image = 1;
text = 0;
};
title = "Something Under the Bed Is Drooling";
};
}
);
kind = "books#volumes";
totalItems = 1;
}
What I want to do is create an object from the items in this dictionary. This method needs to work generically for all books without crashing. Even if they are missing some of the attributes. The attributes I need to extract are:
-authors last name (Need for every author listed if there is more than one)
-authors first name (Need for every author listed if there is more than one)
-title
-description
-smallThumbnail
-thumbnail
-isbn_10 identifier
-category
From these I am going to create a "book" object. i will also create an NSSet of Authors, and each Author has a lastName and firstName
How do I go about doing this?

Answer 1

You should be able to safely use NSDictionary's -valueForKeyPath: to retrieve each value from an item dict:
NSArray *names = [itemDict valueForKeyPath:#"volumeInfo.authors"];
NSString *title = [itemDict valueForKeyPath:#"volumeInfo.title"];
...