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    <p>I've done something similar to Shortseller, but without the use of categories.</p> <p><a href="http://i40.tinypic.com/x3ryp.png">alt text http://i40.tinypic.com/x3ryp.png</a></p> <p><code>InternationalBook</code> and <code>LocalizedBook</code> are both custom managed objects with a one-to-many relationship (one international book to many localised books).</p> <p>In the implementation of <code>InternationalBook</code>, I've added a custom accessor for <code>title</code>:</p> <pre><code>- (NSString *)title { [self willAccessValueForKey:@"title"]; NSString *locTitle = nil; NSPredicate *predicate = [NSPredicate predicateWithFormat:@"locale==%@", [DataManager localeString]]; NSSet *localizedSet = [self.localizedBook filteredSetUsingPredicate:predicate]; if ([localizedSet count] &gt; 0) { locTitle = [[localizedSet valueForKey:@"localizedTitle"] anyObject]; } [self didAccessValueForKey:@"title"]; return locTitle; } </code></pre> <p><code>[DataManager localeString]</code> is a class method which returns the user's language and country code: <code>en_US</code>, <code>fr_FR</code>, etc. See documentation on <code>NSLocale</code> for details.</p> <p>See the "Custom Attribute and To-One Relationship Accessor Methods" section of the Core Data Programming Guide for an explanation of <code>willAccessValueForKey:</code> and <code>didAccessValueForKey:</code>.</p> <p>When populating the data, I grab a string representing the user's current locale (<code>[DataManager localeString]</code>), and store that along the with localised book title in a new <code>LocalizedBook</code> object. Each <code>LocalizedBook</code> instance is added to an <code>NSMutableSet</code>, which represents the one-to-many relationship.</p> <pre><code>NSMutableSet *bookLocalizations = [internationalBook mutableSetValueForKey:@"localizedBook"]; // internationalBook is an instance of InternationalBook // set the values for locale and localizedTitle LocalizedBook *localizedBook = (LocalizedBook *)[NSEntityDescription insertnNewObjectEntityForName:@"LocalizedBook" inManagedObjectContext:self.bookMOC]; localizedBook.locale = [DataManager localeString]; localizedBook.localizedTitle = theLocalizedTitle; // assume theLocalizedTitle has been defined. [bookLocalizations addObject:localizedBook]; [bookLocalizations setValue:localizedBook forKey:@"localizedBook"]; </code></pre> <p>Since the localised titles are being stored in the <code>LocalizedBook</code> managed object, you can make the <code>title</code> attribute a transient, but if you do that you can't use <code>title</code> in a predicate.</p> <p>The nice thing about this approach is that the implementation of the to-many relationship is transparent to any consumers. You simply request <code>internationalBook.title</code> and the custom accessor returns the appropriate value based on the user's locale behind the scenes.</p>
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    1. POGood practices for multiple language data in Core Data
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    1. USGordon Hughes
    1. USGordon Hughes
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    1. POGood practices for multiple language data in Core Data
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    1. COReally useful thank you Gordon, i'm using it.
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      1. USLuca Bartoletti
    2. COExcellent, but how do you manage the situation when a user changes locale? IMHO asking a user to restart the app is rude, but otherwise a lot of work must be done in order to update all fetched and shown text in all view controllers.
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Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

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