Iphone core data updating
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If you have never worked with Core Data before, this mighty framework can seem a little intimidating.
After initial configuration RESTKit fetches data taking care of the network stuff and parses the results into either your custom classes or straight into Core Data.
In this tutorial we will be focusing on the latter.
Core Data is a core competency for Apple developers—but it's notoriously complex, confusing, and crash prone.
Luckily, much of this is resolved with i OS 10's new Core Data APIs.
Eager to see what we’ll have created by the end of this tutorial?
So it’s only natural that we should take some time to learn about it when building apps.
The problem with Core Data As Brent Simmons, at the time developer of successful RSS reader Net News Wire for OS X, wrote a couple of years ago, Core Data can easily become a performance bottleneck in apps requiring a basic operation, such as changing an attribute value or deleting an entity, to be applied to a large set of objects. Data Storage and Management for i OS, OS X, and i Cloud", put it, while in the database world such operations are "very, very easy to do no matter how many" objects you have, they become "painful" with an object graph because they require "to load in all those records, change literally one bit, and then write all those records back out again." Brent Simmons ended up switching away from Core Data and using directly SQLite, but newly introduced batch updates aim to offer an alternative.
The reason for this, according to Brent, and others lays with Core Data being an object graph persistence manager. Core Data batch updates The steps required to execute a batch update are shown below: //-- Create a NSBatch Update Request for your entity NSBatch Update Request *batch Update Request = [[NSBatch Update Request alloc] init With Entity:entity Description]; //-- Our batch update will return an array of objects ID [batch Update Request set Result Type: NSUpdated Object IDs Result Type]; //-- Configure Batch Update Request [batch Update Request set Properties To Update:@]; //-- Execute Batch Request NSError *batch Update Request Error = nil; NSBatch Update Result *batch Update Result = (NSBatch Update Result *)[self.managed Object Context execute Request:batch Update Request error:&batch Update Request Error]; The above snippet of code comes from a full step by step tutorial by Bart Jacobs that shows how to use batch updates in a i OS 8 app.
Instructor Jon Bott starts with a review of the basics, explaining the different architectural data models currently in use, the issues that can arise from these different models, and how the latest changes in Core Data 2016 simplify these models.
He wraps up with hands-on migration to the new APIs and further tips on leveraging them in i OS 10 and mac OS 10.12 apps.