starred/CoreStore-JohnEstropia
1
0
Fork 0
mirror of https://github.com/JohnEstropia/CoreStore.git synced 2026-03-20 00:24:01 +01:00
Code Issues 95 Packages Projects Releases 10 Wiki Activity

Merge branch 'develop'

Browse Source
This commit is contained in:
John Estropia
2015-09-28 20:46:14 +09:00
parent 2a8df0596d b9ec66f425
commit cf9af6eef5
16 changed files with 108 additions and 237 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
README.md
View File

@@ -41,7 +41,7 @@ Unleashing the real power of Core Data with the elegance and safety of Swift
- [Transaction types](#transaction-types)
- [Asynchronous transactions](#asynchronous-transactions)
- [Synchronous transactions](#synchronous-transactions)
- [Detached transactions](#detached-transactions)
- [Unsafe transactions](#unsafe-transactions)
- [Creating objects](#creating-objects)
- [Updating objects](#updating-objects)
- [Deleting objects](#deleting-objects)
@@ -146,7 +146,7 @@ If you are already familiar with the inner workings of CoreData, here is a mappi
| --- | --- |
| `NSManagedObjectModel` / `NSPersistentStoreCoordinator`<br />(.xcdatamodeld file) | `DataStack` |
| `NSPersistentStore`<br />("Configuration"s in the .xcdatamodeld file) | `DataStack` configuration<br />(multiple sqlite / in-memory stores per stack) |
| `NSManagedObjectContext` | `BaseDataTransaction` subclasses<br />(`SynchronousDataTransaction`, `AsynchronousDataTransaction`, `DetachedDataTransaction`) |
| `NSManagedObjectContext` | `BaseDataTransaction` subclasses<br />(`SynchronousDataTransaction`, `AsynchronousDataTransaction`, `UnsafeDataTransaction`) |
Popular libraries [RestKit](https://github.com/RestKit/RestKit) and [MagicalRecord](https://github.com/magicalpanda/MagicalRecord) set up their `NSManagedObjectContext`s this way:
@@ -376,7 +376,7 @@ CoreStore.beginAsynchronous { (transaction) -> Void in
```
The `commit()` method saves the changes to the persistent store. If `commit()` is not called when the transaction block completes, all changes within the transaction is discarded.
The examples above use `beginAsynchronous(...)`, but there are actually 3 types of transactions at your disposal: *asynchronous*, *synchronous*, and *detached*.
The examples above use `beginAsynchronous(...)`, but there are actually 3 types of transactions at your disposal: *asynchronous*, *synchronous*, and *unsafe*.
### Transaction types
@@ -402,10 +402,10 @@ CoreStore.beginSynchronous { (transaction) -> Void in
Since `beginSynchronous(...)` technically blocks two queues (the caller's queue and the transaction's background queue), it is considered less safe as it's more prone to deadlock. Take special care that the closure does not block on any other external queues.
#### Detached transactions
#### Unsafe transactions
are special in that they do not enclose updates within a closure:
```swift
let transaction = CoreStore.beginDetached()
let transaction = CoreStore.beginUnsafe()
// make changes
downloadJSONWithCompletion({ (json) -> Void in
@@ -420,7 +420,7 @@ downloadAnotherJSONWithCompletion({ (json) -> Void in
```
This allows for non-contiguous updates. Do note that this flexibility comes with a price: you are now responsible for managing concurrency for the transaction. As uncle Ben said, "with great power comes great race conditions."
As the above example also shows, only detached transactions are allowed to call `commit()` multiple times; doing so with synchronous and asynchronous transactions will trigger an assert.
As the above example also shows, only unsafe transactions are allowed to call `commit()` multiple times; doing so with synchronous and asynchronous transactions will trigger an assert.
You've seen how to create transactions, but we have yet to see how to make *creates*, *updates*, and *deletes*. The 3 types of transactions above are all subclasses of `BaseDataTransaction`, which implements the methods shown below.