UIDocument
- 如何使用icloud 同步文件
- 如何添加文件到icloud
- 如何获取icloud中文件列表
- 如何删除icloud中文件
- 多个设备同时打开一个document 如何同步
- 多个设备如何同步document列表
- 如何处理冲突
1. 基本配置
首先添加icloud capability，这个需要开发者账号, 然后添加一个icloud container id。
2. 添加数据
想把一个文件数据放到icloud上，要先检查icloud 是否可用
- 检查icloud是否已经可用，并获取到icloud container url
guard FileManager.default.ubiquityIdentityToken != nil else {
print("⛔️ iCloud isn't enabled yet. Please enable iCloud and run again.")
return nil
}
// Dispatch to a global queue because url(forUbiquityContainerIdentifier:) might take a nontrivial
// amount of time to set up iCloud and return the requested URL
//
DispatchQueue.global().async {
if let url = FileManager.default.url(forUbiquityContainerIdentifier: containerIdentifier) {
DispatchQueue.main.async {
self.containerRootURL = url
}
return
}
print("⛔️ Failed to retrieve iCloud container URL for:\(containerIdentifier ?? "nil")\n"
+ "Make sure your iCloud is available and run again.")
}
上面代码检查icloud 功能是否开启，并获取icloud container 容器的url 地址。
- 下面要封装数据，然后放到icloud container里面
需要自定义类继承UIDocument，然后通过操作document来实现文件的增删改
let document = Document(fileURL: fileURL)
document.save(to: fileURL, for: .forCreating) { _ in
document.close { success in
if !success {
print("Failed to close the document: \(fileURL)")
}
completionHandler?(success)
}
}
func removeDocument(at fileURL: URL) {
DispatchQueue.global().async {
NSFileCoordinator().coordinate(writingItemAt: fileURL, options: .forDeleting, error: nil) { newURL in
do {
try FileManager.default.removeItem(atPath: newURL.path)
} catch let error as NSError {
print(error.localizedDescription)
}
}
}
}
要看看文件是否已经添加成功，可以在设置->iCloud->存储空间，
但是要配置一些数据
<key>NSUbiquitousContainers</key>
<dict>
<key>iCloud.com.example.apple-samplecode.SimpleiCloudDocument</key>
<dict>
<key>NSUbiquitousContainerIsDocumentScopePublic</key> // 是否支持在File app中查看
<true/>
<key>NSUbiquitousContainerName</key> // 在File app中显示的名称
<string>SimpleiCloudDocument</string>
<key>NSUbiquitousContainerSupportedFolderLevels</key>
<string>ANY</string>
</dict>
</dict>
要实现在File app查看自己app中数据，并实现点击自定义格式文件能打开app，要实现配置CFBundleDocumentTypes and UTExportedTypeDeclarations
设置LSSupportsOpeningDocumentsInPlace = true
实现scene(_:openURLContexts:) 方法 具体配置看demo
<key>UTExportedTypeDeclarations</key>
<array>
<dict>
<key>UTTypeConformsTo</key>
<array>
<string>com.apple.package</string>
<string>public.content</string>
<string>public.data</string>
</array>
<key>UTTypeDescription</key>
<string>AIScanner</string>
<key>UTTypeIconFiles</key>
<string>Icon.png</string>
<key>UTTypeIdentifier</key>
<string>com.daping.pdfdoc.icloud.aisc</string>
<key>UTTypeTagSpecification</key>
<dict>
<key>public.filename-extension</key>
<array>
<string>aisc</string>
</array>
<key>public.mime-type</key>
<string>application/aisc</string>
</dict>
</dict>
</array>
<key>CFBundleDocumentTypes</key>
<array>
<dict>
<key>CFBundleTypeIconFiles</key>
<array/>
<key>CFBundleTypeName</key>
<string>AIScanner</string>
<key>CFBundleTypeRole</key>
<string>Editor</string>
<key>LSHandlerRank</key>
<string>Owner</string>
<key>LSTypeIsPackage</key>
<true/>
<key>LSItemContentTypes</key>
<array>
<string>com.daping.pdfdoc.icloud.aisc</string>
</array>
</dict>
</array>
<key>NSUbiquitousContainers</key>
<dict>
<key>iCloud.com.danping.pdfdoc.aiscanner</key>
<dict>
<key>NSUbiquitousContainerIsDocumentScopePublic</key>
<true/>
<key>NSUbiquitousContainerName</key>
<string>SimpleiCloudDocument</string>
<key>NSUbiquitousContainerSupportedFolderLevels</key>
<string>ANY</string>
</dict>
</dict>
<key>LSSupportsOpeningDocumentsInPlace</key>
<true/>
3. 查询数据
如何查询icloud document
当在一个设备添加了document， icloud并不会立即把数据同步到其他设备，而是先同步metadata，因为metadata 数据量小，根据不同设置选择是否立即同步数据，iOS设备不会立即同步，mac会立即同步。
其他设置收到icloud 新数据通知后，数据并没有同步过来，所有不能使用FileManager API 去操作数据。
要查询和监听icloud 数据变换要使用 NSMetadataQuery 接口。
metadataQuery.notificationBatchingInterval = 1
metadataQuery.searchScopes = [NSMetadataQueryUbiquitousDataScope, NSMetadataQueryUbiquitousDocumentsScope]
metadataQuery.predicate = NSPredicate(format: "%K LIKE %@", NSMetadataItemFSNameKey, "*." + Document.extensionName)
metadataQuery.sortDescriptors = [NSSortDescriptor(key: NSMetadataItemFSNameKey, ascending: true)]
metadataQuery.start()
当读取数据的时候，为了避免冲突，先关闭查询接口，然后再开启。
func metadataItemList() -> [MetadataItem] {
var result = [MetadataItem]()
metadataQuery.disableUpdates()
if let metadatItems = metadataQuery.results as? [NSMetadataItem] {
result = metadataItemList(from: metadatItems)
}
metadataQuery.enableUpdates()
return result
}
4. 冲突解决
icloud 多个设备之前同步数据，不同的网络环境，冲突不可避免。比如多个设备都断网，然后同时修改数据，再同时打开网络， 就会出现冲突。
@objc
func documentStateChanged(_ notification: Notification) {
guard let document = document else { return }
printDocumentState(for: document)
// The document state is normal.
// Update the UI with unpresented peer changes, if any.
//
if document.documentState == .normal {
navigationItem.rightBarButtonItem?.isEnabled = true
handleConflictsItem.isEnabled = false
if !document.unpresentedPeerChanges.isEmpty {
let changes = document.unpresentedPeerChanges
document.clearUnpresentedPeerChanges()
updateCollectionView(with: changes)
}
return
}
// The document has conflicts but no error.
// Update the UI with unpresented peer changes if any.
//
if document.documentState == .inConflict {
navigationItem.rightBarButtonItem?.isEnabled = true
handleConflictsItem.isEnabled = true
if !document.unpresentedPeerChanges.isEmpty {
let changes = document.unpresentedPeerChanges
document.clearUnpresentedPeerChanges()
updateCollectionView(with: changes)
}
return
}
// The document is in a closed state with no error. Clear the UI.
//
if document.documentState == .closed {
navigationItem.rightBarButtonItem?.isEnabled = false
handleConflictsItem.isEnabled = false
title = ""
var snapshot = DiffableImageSourceSnapshot()
snapshot.appendSections([0])
diffableImageSource.apply(snapshot)
return
}
// The document has conflicts. Enable the toolbar item.
//
if document.documentState.contains(.inConflict) {
handleConflictsItem.isEnabled = true
}
// The document is editingDisabled. Disable the UI for editing.
//
if document.documentState.contains(.editingDisabled) {
navigationItem.rightBarButtonItem?.isEnabled = false
handleConflictsItem.isEnabled = false
}
}
上面代码显示 当打开一个document后，可以监听document的变化，包括冲突
不过解决冲突很简单的，Document 监听状态变化，当检测到冲突的时候，根据不同策略去解决，比如再简单的根据修改时间，最新的保留，其他的删除。
private func resolveConflictsAsynchronously(document: Document, completionHandler: ((Bool) -> Void)?) {
DispatchQueue.global().async {
NSFileCoordinator().coordinate(writingItemAt: document.fileURL,
options: .contentIndependentMetadataOnly, error: nil) { newURL in
let shouldRevert = self.pickLatestVersion(for: newURL)
completionHandler?(shouldRevert)
}
}
}
private func pickLatestVersion(for documentURL: URL) -> Bool {
guard let versionsInConflict = NSFileVersion.unresolvedConflictVersionsOfItem(at: documentURL),
let currentVersion = NSFileVersion.currentVersionOfItem(at: documentURL) else {
return false
}
var shouldRevert = false
var winner = currentVersion
for version in versionsInConflict {
if let date1 = version.modificationDate, let date2 = winner.modificationDate,
date1 > date2 {
winner = version
}
}
if winner != currentVersion {
do {
try winner.replaceItem(at: documentURL)
shouldRevert = true
} catch {
print("Failed to replace version: \(error)")
}
}
do {
try NSFileVersion.removeOtherVersionsOfItem(at: documentURL)
} catch {
print("Failed to remove other versions: \(error)")
}
return shouldRevert
}
