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comments cleanup

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John Rommel Estropia
2016-02-17 01:38:26 +09:00
parent def105e73a
commit 66892f22a3
47 changed files with 1749 additions and 1750 deletions
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CoreStore/Migrating/MigrationChain.swift
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@@ -30,36 +30,36 @@ import CoreData
// MARK: - MigrationChain
/**
A `MigrationChain` indicates the sequence of model versions to be used as the order for incremental migration. This is typically passed to the `DataStack` initializer and will be applied to all stores added to the `DataStack` with `addSQLiteStore(...)` and its variants.
Initializing with empty values (either `nil`, `[]`, or `[:]`) instructs the `DataStack` to use the .xcdatamodel's current version as the final version, and to disable incremental migrations:
let dataStack = DataStack(migrationChain: nil)
This means that the mapping model will be computed from the store's version straight to the `DataStack`'s model version.
To support incremental migrations, specify the linear order of versions:
let dataStack = DataStack(migrationChain:
["MyAppModel", "MyAppModelV2", "MyAppModelV3", "MyAppModelV4"])
or for more complex migration paths, a version tree that maps the key-values to the source-destination versions:
let dataStack = DataStack(migrationChain: [
"MyAppModel": "MyAppModelV3",
"MyAppModelV2": "MyAppModelV4",
"MyAppModelV3": "MyAppModelV4"
])
This allows for different migration paths depending on the starting version. The example above resolves to the following paths:
- MyAppModel-MyAppModelV3-MyAppModelV4
- MyAppModelV2-MyAppModelV4
- MyAppModelV3-MyAppModelV4
The `MigrationChain` is validated when passed to the `DataStack` and unless it is empty, will raise an assertion if any of the following conditions are met:
- a version appears twice in an array
- a version appears twice as a key in a dictionary literal
- a loop is found in any of the paths
*/
A `MigrationChain` indicates the sequence of model versions to be used as the order for incremental migration. This is typically passed to the `DataStack` initializer and will be applied to all stores added to the `DataStack` with `addSQLiteStore(...)` and its variants.
Initializing with empty values (either `nil`, `[]`, or `[:]`) instructs the `DataStack` to use the .xcdatamodel's current version as the final version, and to disable incremental migrations:
```
let dataStack = DataStack(migrationChain: nil)
```
This means that the mapping model will be computed from the store's version straight to the `DataStack`'s model version.
To support incremental migrations, specify the linear order of versions:
```
let dataStack = DataStack(migrationChain:
["MyAppModel", "MyAppModelV2", "MyAppModelV3", "MyAppModelV4"])
```
or for more complex migration paths, a version tree that maps the key-values to the source-destination versions:
```
let dataStack = DataStack(migrationChain: [
"MyAppModel": "MyAppModelV3",
"MyAppModelV2": "MyAppModelV4",
"MyAppModelV3": "MyAppModelV4"
])
```
This allows for different migration paths depending on the starting version. The example above resolves to the following paths:
- MyAppModel-MyAppModelV3-MyAppModelV4
- MyAppModelV2-MyAppModelV4
- MyAppModelV3-MyAppModelV4
The `MigrationChain` is validated when passed to the `DataStack` and unless it is empty, will raise an assertion if any of the following conditions are met:
- a version appears twice in an array
- a version appears twice as a key in a dictionary literal
- a loop is found in any of the paths
*/
public struct MigrationChain: NilLiteralConvertible, StringLiteralConvertible, DictionaryLiteralConvertible, ArrayLiteralConvertible {
// MARK: NilLiteralConvertible