diff options
| author | PliablePixels <pliablepixels@gmail.com> | 2015-06-27 09:52:06 -0400 |
|---|---|---|
| committer | PliablePixels <pliablepixels@gmail.com> | 2015-06-27 09:52:06 -0400 |
| commit | 319d4cb6670729708c19ad50b0146d1bcb7b4719 (patch) | |
| tree | c61e9723a1fd217b1816c987bba66e470e73bf02 /plugins/cordova-plugin-file/README.md | |
| parent | fdc42fae48db0fef5fbdc9ef51a27d219aea3a72 (diff) | |
Added ability to log key events to file and email (useful for release debugging)
Diffstat (limited to 'plugins/cordova-plugin-file/README.md')
| -rw-r--r-- | plugins/cordova-plugin-file/README.md | 452 |
1 files changed, 452 insertions, 0 deletions
diff --git a/plugins/cordova-plugin-file/README.md b/plugins/cordova-plugin-file/README.md new file mode 100644 index 00000000..99d7cf3a --- /dev/null +++ b/plugins/cordova-plugin-file/README.md @@ -0,0 +1,452 @@ +<!-- +# license: Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you under the Apache License, Version 2.0 (the +# "License"); you may not use this file except in compliance +# with the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, +# software distributed under the License is distributed on an +# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +# KIND, either express or implied. See the License for the +# specific language governing permissions and limitations +# under the License. +--> + +# cordova-plugin-file + +[](https://travis-ci.org/apache/cordova-plugin-file) + +This plugin implements a File API allowing read/write access to files residing on the device. + +This plugin is based on several specs, including : +The HTML5 File API +[http://www.w3.org/TR/FileAPI/](http://www.w3.org/TR/FileAPI/) + +The (now-defunct) Directories and System extensions +Latest: +[http://www.w3.org/TR/2012/WD-file-system-api-20120417/](http://www.w3.org/TR/2012/WD-file-system-api-20120417/) +Although most of the plugin code was written when an earlier spec was current: +[http://www.w3.org/TR/2011/WD-file-system-api-20110419/](http://www.w3.org/TR/2011/WD-file-system-api-20110419/) + +It also implements the FileWriter spec : +[http://dev.w3.org/2009/dap/file-system/file-writer.html](http://dev.w3.org/2009/dap/file-system/file-writer.html) + +For usage, please refer to HTML5 Rocks' excellent [FileSystem article.](http://www.html5rocks.com/en/tutorials/file/filesystem/) + +For an overview of other storage options, refer to Cordova's +[storage guide](http://cordova.apache.org/docs/en/edge/cordova_storage_storage.md.html). + +This plugin defines global `cordova.file` object. + +Although in the global scope, it is not available until after the `deviceready` event. + + document.addEventListener("deviceready", onDeviceReady, false); + function onDeviceReady() { + console.log(cordova.file); + } + +## Installation + + cordova plugin add cordova-plugin-file + +## Supported Platforms + +- Amazon Fire OS +- Android +- BlackBerry 10 +- Firefox OS +- iOS +- Windows Phone 7 and 8* +- Windows 8* +- Windows* +- Browser + +\* _These platforms do not support `FileReader.readAsArrayBuffer` nor `FileWriter.write(blob)`._ + +## Where to Store Files + +As of v1.2.0, URLs to important file-system directories are provided. +Each URL is in the form _file:///path/to/spot/_, and can be converted to a +`DirectoryEntry` using `window.resolveLocalFileSystemURL()`. + +* `cordova.file.applicationDirectory` - Read-only directory where the application + is installed. (_iOS_, _Android_, _BlackBerry 10_) + +* `cordova.file.applicationStorageDirectory` - Root directory of the application's + sandbox; on iOS this location is read-only (but specific subdirectories [like + `/Documents`] are read-write). All data contained within is private to the app. ( + _iOS_, _Android_, _BlackBerry 10_) + +* `cordova.file.dataDirectory` - Persistent and private data storage within the + application's sandbox using internal memory (on Android, if you need to use + external memory, use `.externalDataDirectory`). On iOS, this directory is not + synced with iCloud (use `.syncedDataDirectory`). (_iOS_, _Android_, _BlackBerry 10_) + +* `cordova.file.cacheDirectory` - Directory for cached data files or any files + that your app can re-create easily. The OS may delete these files when the device + runs low on storage, nevertheless, apps should not rely on the OS to delete files + in here. (_iOS_, _Android_, _BlackBerry 10_) + +* `cordova.file.externalApplicationStorageDirectory` - Application space on + external storage. (_Android_) + +* `cordova.file.externalDataDirectory` - Where to put app-specific data files on + external storage. (_Android_) + +* `cordova.file.externalCacheDirectory` - Application cache on external storage. + (_Android_) + +* `cordova.file.externalRootDirectory` - External storage (SD card) root. (_Android_, _BlackBerry 10_) + +* `cordova.file.tempDirectory` - Temp directory that the OS can clear at will. Do not + rely on the OS to clear this directory; your app should always remove files as + applicable. (_iOS_) + +* `cordova.file.syncedDataDirectory` - Holds app-specific files that should be synced + (e.g. to iCloud). (_iOS_) + +* `cordova.file.documentsDirectory` - Files private to the app, but that are meaningful + to other application (e.g. Office files). (_iOS_) + +* `cordova.file.sharedDirectory` - Files globally available to all applications (_BlackBerry 10_) + +## File System Layouts + +Although technically an implementation detail, it can be very useful to know how +the `cordova.file.*` properties map to physical paths on a real device. + +### iOS File System Layout + +| Device Path | `cordova.file.*` | `iosExtraFileSystems` | r/w? | persistent? | OS clears | sync | private | +|:-----------------------------------------------|:----------------------------|:----------------------|:----:|:-----------:|:---------:|:----:|:-------:| +| `/var/mobile/Applications/<UUID>/` | applicationStorageDirectory | - | r | N/A | N/A | N/A | Yes | +| `appname.app/` | applicationDirectory | bundle | r | N/A | N/A | N/A | Yes | +| `www/` | - | - | r | N/A | N/A | N/A | Yes | +| `Documents/` | documentsDirectory | documents | r/w | Yes | No | Yes | Yes | +| `NoCloud/` | - | documents-nosync | r/w | Yes | No | No | Yes | +| `Library` | - | library | r/w | Yes | No | Yes? | Yes | +| `NoCloud/` | dataDirectory | library-nosync | r/w | Yes | No | No | Yes | +| `Cloud/` | syncedDataDirectory | - | r/w | Yes | No | Yes | Yes | +| `Caches/` | cacheDirectory | cache | r/w | Yes* | Yes\*\*\*| No | Yes | +| `tmp/` | tempDirectory | - | r/w | No\*\* | Yes\*\*\*| No | Yes | + + + \* Files persist across app restarts and upgrades, but this directory can + be cleared whenever the OS desires. Your app should be able to recreate any + content that might be deleted. + +\*\* Files may persist across app restarts, but do not rely on this behavior. Files + are not guaranteed to persist across updates. Your app should remove files from + this directory when it is applicable, as the OS does not guarantee when (or even + if) these files are removed. + +\*\*\* The OS may clear the contents of this directory whenever it feels it is + necessary, but do not rely on this. You should clear this directory as + appropriate for your application. + +### Android File System Layout + +| Device Path | `cordova.file.*` | `AndroidExtraFileSystems` | r/w? | persistent? | OS clears | private | +|:------------------------------------------------|:----------------------------|:--------------------------|:----:|:-----------:|:---------:|:-------:| +| `file:///android_asset/` | applicationDirectory | | r | N/A | N/A | Yes | +| `/data/data/<app-id>/` | applicationStorageDirectory | - | r/w | N/A | N/A | Yes | +| `cache` | cacheDirectory | cache | r/w | Yes | Yes\* | Yes | +| `files` | dataDirectory | files | r/w | Yes | No | Yes | +| `Documents` | | documents | r/w | Yes | No | Yes | +| `<sdcard>/` | externalRootDirectory | sdcard | r/w | Yes | No | No | +| `Android/data/<app-id>/` | externalApplicationStorageDirectory | - | r/w | Yes | No | No | +| `cache` | externalCacheDirectry | cache-external | r/w | Yes | No\*\*| No | +| `files` | externalDataDirectory | files-external | r/w | Yes | No | No | + +\* The OS may periodically clear this directory, but do not rely on this behavior. Clear + the contents of this directory as appropriate for your application. Should a user + purge the cache manually, the contents of this directory are removed. + +\*\* The OS does not clear this directory automatically; you are responsible for managing + the contents yourself. Should the user purge the cache manually, the contents of the + directory are removed. + +**Note**: If external storage can't be mounted, the `cordova.file.external*` +properties are `null`. + +### BlackBerry 10 File System Layout + +| Device Path | `cordova.file.*` | r/w? | persistent? | OS clears | private | +|:-------------------------------------------------------------|:----------------------------|:----:|:-----------:|:---------:|:-------:| +| `file:///accounts/1000/appdata/<app id>/` | applicationStorageDirectory | r | N/A | N/A | Yes | +| `app/native` | applicationDirectory | r | N/A | N/A | Yes | +| `data/webviews/webfs/temporary/local__0` | cacheDirectory | r/w | No | Yes | Yes | +| `data/webviews/webfs/persistent/local__0` | dataDirectory | r/w | Yes | No | Yes | +| `file:///accounts/1000/removable/sdcard` | externalRemovableDirectory | r/w | Yes | No | No | +| `file:///accounts/1000/shared` | sharedDirectory | r/w | Yes | No | No | + +*Note*: When application is deployed to work perimeter, all paths are relative to /accounts/1000-enterprise. + +## Android Quirks + +### Android Persistent storage location + +There are multiple valid locations to store persistent files on an Android +device. See [this page](http://developer.android.com/guide/topics/data/data-storage.html) +for an extensive discussion of the various possibilities. + +Previous versions of the plugin would choose the location of the temporary and +persistent files on startup, based on whether the device claimed that the SD +Card (or equivalent storage partition) was mounted. If the SD Card was mounted, +or if a large internal storage partition was available (such as on Nexus +devices,) then the persistent files would be stored in the root of that space. +This meant that all Cordova apps could see all of the files available on the +card. + +If the SD card was not available, then previous versions would store data under +`/data/data/<packageId>`, which isolates apps from each other, but may still +cause data to be shared between users. + +It is now possible to choose whether to store files in the internal file +storage location, or using the previous logic, with a preference in your +application's `config.xml` file. To do this, add one of these two lines to +`config.xml`: + + <preference name="AndroidPersistentFileLocation" value="Internal" /> + + <preference name="AndroidPersistentFileLocation" value="Compatibility" /> + +Without this line, the File plugin will use `Compatibility` as the default. If +a preference tag is present, and is not one of these values, the application +will not start. + +If your application has previously been shipped to users, using an older (pre- +1.0) version of this plugin, and has stored files in the persistent filesystem, +then you should set the preference to `Compatibility`. Switching the location to +"Internal" would mean that existing users who upgrade their application may be +unable to access their previously-stored files, depending on their device. + +If your application is new, or has never previously stored files in the +persistent filesystem, then the `Internal` setting is generally recommended. + +### Slow recursive operations for /android_asset + +Listing asset directories is really slow on Android. You can speed it up though, by +adding `src/android/build-extras.gradle` to the root of your android project (also +requires cordova-android@4.0.0 or greater). + +## iOS Quirks + +- `cordova.file.applicationStorageDirectory` is read-only; attempting to store + files within the root directory will fail. Use one of the other `cordova.file.*` + properties defined for iOS (only `applicationDirectory` and `applicationStorageDirectory` are + read-only). +- `FileReader.readAsText(blob, encoding)` + - The `encoding` parameter is not supported, and UTF-8 encoding is always in effect. + +### iOS Persistent storage location + +There are two valid locations to store persistent files on an iOS device: the +Documents directory and the Library directory. Previous versions of the plugin +only ever stored persistent files in the Documents directory. This had the +side-effect of making all of an application's files visible in iTunes, which +was often unintended, especially for applications which handle lots of small +files, rather than producing complete documents for export, which is the +intended purpose of the directory. + +It is now possible to choose whether to store files in the documents or library +directory, with a preference in your application's `config.xml` file. To do this, +add one of these two lines to `config.xml`: + + <preference name="iosPersistentFileLocation" value="Library" /> + + <preference name="iosPersistentFileLocation" value="Compatibility" /> + +Without this line, the File plugin will use `Compatibility` as the default. If +a preference tag is present, and is not one of these values, the application +will not start. + +If your application has previously been shipped to users, using an older (pre- +1.0) version of this plugin, and has stored files in the persistent filesystem, +then you should set the preference to `Compatibility`. Switching the location to +`Library` would mean that existing users who upgrade their application would be +unable to access their previously-stored files. + +If your application is new, or has never previously stored files in the +persistent filesystem, then the `Library` setting is generally recommended. + +## Firefox OS Quirks + +The File System API is not natively supported by Firefox OS and is implemented +as a shim on top of indexedDB. + +* Does not fail when removing non-empty directories +* Does not support metadata for directories +* Methods `copyTo` and `moveTo` do not support directories + +The following data paths are supported: +* `applicationDirectory` - Uses `xhr` to get local files that are packaged with the app. +* `dataDirectory` - For persistent app-specific data files. +* `cacheDirectory` - Cached files that should survive app restarts (Apps should not rely +on the OS to delete files in here). + +## Browser Quirks + +### Common quirks and remarks +- Each browser uses its own sandboxed filesystem. IE and Firefox use IndexedDB as a base. +All browsers use forward slash as directory separator in a path. +- Directory entries have to be created successively. +For example, the call `fs.root.getDirectory('dir1/dir2', {create:true}, successCallback, errorCallback)` +will fail if dir1 did not exist. +- The plugin requests user permission to use persistent storage at the application first start. +- Plugin supports `cdvfile://localhost` (local resources) only. I.e. external resources are not supported via `cdvfile`. +- The plugin does not follow ["File System API 8.3 Naming restrictions"](http://www.w3.org/TR/2011/WD-file-system-api-20110419/#naming-restrictions). +- Blob and File' `close` function is not supported. +- `FileSaver` and `BlobBuilder` are not supported by this plugin and don't have stubs. +- The plugin does not support `requestAllFileSystems`. This function is also missing in the specifications. +- Entries in directory will not be removed if you use `create: true` flag for existing directory. +- Files created via constructor are not supported. You should use entry.file method instead. +- Each browser uses its own form for blob URL references. +- `readAsDataURL` function is supported, but the mediatype in Chrome depends on entry name extension, +mediatype in IE is always empty (which is the same as `text-plain` according the specification), +the mediatype in Firefox is always `application/octet-stream`. +For example, if the content is `abcdefg` then Firefox returns `data:application/octet-stream;base64,YWJjZGVmZw==`, +IE returns `data:;base64,YWJjZGVmZw==`, Chrome returns `data:<mediatype depending on extension of entry name>;base64,YWJjZGVmZw==`. +- `toInternalURL` returns the path in the form `file:///persistent/path/to/entry` (Firefox, IE). +Chrome returns the path in the form `cdvfile://localhost/persistent/file`. + +### Chrome quirks +- Chrome filesystem is not immediately ready after device ready event. As a workaround you can subscribe to `filePluginIsReady` event. +Example: +```javascript +window.addEventListener('filePluginIsReady', function(){ console.log('File plugin is ready');}, false); +``` +You can use `window.isFilePluginReadyRaised` function to check whether event was already raised. +- window.requestFileSystem TEMPORARY and PERSISTENT filesystem quotas are not limited in Chrome. +- To increase persistent storage in Chrome you need to call `window.initPersistentFileSystem` method. Persistent storage quota is 5 MB by default. +- Chrome requires `--allow-file-access-from-files` run argument to support API via `file:///` protocol. +- `File` object will be not changed if you use flag `{create:true}` when getting an existing `Entry`. +- events `cancelable` property is set to true in Chrome. This is contrary to the [specification](http://dev.w3.org/2009/dap/file-system/file-writer.html). +- `toURL` function in Chrome returns `filesystem:`-prefixed path depending on application host. +For example, `filesystem:file:///persistent/somefile.txt`, `filesystem:http://localhost:8080/persistent/somefile.txt`. +- `toURL` function result does not contain trailing slash in case of directory entry. +Chrome resolves directories with slash-trailed urls correctly though. +- `resolveLocalFileSystemURL` method requires the inbound `url` to have `filesystem` prefix. For example, `url` parameter for `resolveLocalFileSystemURL` +should be in the form `filesystem:file:///persistent/somefile.txt` as opposed to the form `file:///persistent/somefile.txt` in Android. +- Deprecated `toNativeURL` function is not supported and does not have a stub. +- `setMetadata` function is not stated in the specifications and not supported. +- INVALID_MODIFICATION_ERR (code: 9) is thrown instead of SYNTAX_ERR(code: 8) on requesting of a non-existant filesystem. +- INVALID_MODIFICATION_ERR (code: 9) is thrown instead of PATH_EXISTS_ERR(code: 12) on trying to exclusively create a file or directory, which already exists. +- INVALID_MODIFICATION_ERR (code: 9) is thrown instead of NO_MODIFICATION_ALLOWED_ERR(code: 6) on trying to call removeRecursively on the root file system. +- INVALID_MODIFICATION_ERR (code: 9) is thrown instead of NOT_FOUND_ERR(code: 1) on trying to moveTo directory that does not exist. + +### IndexedDB-based impl quirks (Firefox and IE) +- `.` and `..` are not supported. +- IE does not support `file:///`-mode; only hosted mode is supported (http://localhost:xxxx). +- Firefox filesystem size is not limited but each 50MB extension will request a user permission. +IE10 allows up to 10mb of combined AppCache and IndexedDB used in implementation of filesystem without prompting, +once you hit that level you will be asked if you want to allow it to be increased up to a max of 250mb per site. +So `size` parameter for `requestFileSystem` function does not affect filesystem in Firefox and IE. +- `readAsBinaryString` function is not stated in the Specs and not supported in IE and does not have a stub. +- `file.type` is always null. +- You should not create entry using DirectoryEntry instance callback result which was deleted. +Otherwise, you will get a 'hanging entry'. +- Before you can read a file, which was just written you need to get a new instance of this file. +- `setMetadata` function, which is not stated in the Specs supports `modificationTime` field change only. +- `copyTo` and `moveTo` functions do not support directories. +- Directories metadata is not supported. +- Both Entry.remove and directoryEntry.removeRecursively don't fail when removing +non-empty directories - directories being removed are cleaned along with contents instead. +- `abort` and `truncate` functions are not supported. +- progress events are not fired. For example, this handler will be not executed: +```javascript +writer.onprogress = function() { /*commands*/ }; +``` + +## Upgrading Notes + +In v1.0.0 of this plugin, the `FileEntry` and `DirectoryEntry` structures have changed, +to be more in line with the published specification. + +Previous (pre-1.0.0) versions of the plugin stored the device-absolute-file-location +in the `fullPath` property of `Entry` objects. These paths would typically look like + + /var/mobile/Applications/<application UUID>/Documents/path/to/file (iOS) + /storage/emulated/0/path/to/file (Android) + +These paths were also returned by the `toURL()` method of the `Entry` objects. + +With v1.0.0, the `fullPath` attribute is the path to the file, _relative to the root of +the HTML filesystem_. So, the above paths would now both be represented by a `FileEntry` +object with a `fullPath` of + + /path/to/file + +If your application works with device-absolute-paths, and you previously retrieved those +paths through the `fullPath` property of `Entry` objects, then you should update your code +to use `entry.toURL()` instead. + +For backwards compatibility, the `resolveLocalFileSystemURL()` method will accept a +device-absolute-path, and will return an `Entry` object corresponding to it, as long as that +file exists within either the `TEMPORARY` or `PERSISTENT` filesystems. + +This has particularly been an issue with the File-Transfer plugin, which previously used +device-absolute-paths (and can still accept them). It has been updated to work correctly +with FileSystem URLs, so replacing `entry.fullPath` with `entry.toURL()` should resolve any +issues getting that plugin to work with files on the device. + +In v1.1.0 the return value of `toURL()` was changed (see [CB-6394] (https://issues.apache.org/jira/browse/CB-6394)) +to return an absolute 'file://' URL. wherever possible. To ensure a 'cdvfile:'-URL you can use `toInternalURL()` now. +This method will now return filesystem URLs of the form + + cdvfile://localhost/persistent/path/to/file + +which can be used to identify the file uniquely. + +## List of Error Codes and Meanings +When an error is thrown, one of the following codes will be used. + +| Code | Constant | +|-----:|:------------------------------| +| 1 | `NOT_FOUND_ERR` | +| 2 | `SECURITY_ERR` | +| 3 | `ABORT_ERR` | +| 4 | `NOT_READABLE_ERR` | +| 5 | `ENCODING_ERR` | +| 6 | `NO_MODIFICATION_ALLOWED_ERR` | +| 7 | `INVALID_STATE_ERR` | +| 8 | `SYNTAX_ERR` | +| 9 | `INVALID_MODIFICATION_ERR` | +| 10 | `QUOTA_EXCEEDED_ERR` | +| 11 | `TYPE_MISMATCH_ERR` | +| 12 | `PATH_EXISTS_ERR` | + +## Configuring the Plugin (Optional) + +The set of available filesystems can be configured per-platform. Both iOS and +Android recognize a <preference> tag in `config.xml` which names the +filesystems to be installed. By default, all file-system roots are enabled. + + <preference name="iosExtraFilesystems" value="library,library-nosync,documents,documents-nosync,cache,bundle,root" /> + <preference name="AndroidExtraFilesystems" value="files,files-external,documents,sdcard,cache,cache-external,root" /> + +### Android + +* `files`: The application's internal file storage directory +* `files-external`: The application's external file storage directory +* `sdcard`: The global external file storage directory (this is the root of the SD card, if one is installed). You must have the `android.permission.WRITE_EXTERNAL_STORAGE` permission to use this. +* `cache`: The application's internal cache directory +* `cache-external`: The application's external cache directory +* `root`: The entire device filesystem + +Android also supports a special filesystem named "documents", which represents a "/Documents/" subdirectory within the "files" filesystem. + +### iOS + +* `library`: The application's Library directory +* `documents`: The application's Documents directory +* `cache`: The application's Cache directory +* `bundle`: The application's bundle; the location of the app itself on disk (read-only) +* `root`: The entire device filesystem + +By default, the library and documents directories can be synced to iCloud. You can also request two additional filesystems, `library-nosync` and `documents-nosync`, which represent a special non-synced directory within the `/Library` or `/Documents` filesystem. |