LGTM, let me know if I can help on something. Would be good to have this API on all the platforms we support.
On 03-03-2014 12:11, Gao, Shawn wrote:
*Description:* Native file API allows web app developer to read, write and enumerate native file system via JavaScript. From Webapp developer perspective, most of interfaces in W3C _File API: Directories and System_ <http://www.w3.org/TR/file-system-api/> [1] and_File API: Writer_ <http://www.w3.org/TR/file-writer-api/>[2] will be reused. For example, FileEntry, DirectoryEntry, FileWriter, etc. In Chromium technical scope, there are two related file system API: W3C file API[1][2] and _Chrome extension file API_ <http://developer.chrome.com/apps/app_storage>[3]. Neither one can satisfy above requirements: 1. W3C file API is sandbox file system. 2. Chrome extension file API is only available on top of chrome extension, which won’t support on Crosswalk. Secondly, it pops up file chooser dialog each time for security concern. *Affected component:* 1. xwalk/runtime/renderer/ Add code here to handle JavaScript function call to Isolated File System API. Send Isolated File System requests to browser process through IPC. 2. xwalk/runtime/browser/ Handle Isolated File System requests from render process 3. xwalk/experimental/ Inject Isolated File System JavaScript code to render via xwalk extension mechanism. *Related feature: * _https://crosswalk-project.org/jira/browse/XWALK-672_ *Target Release:*** Crosswalk 6 *Implementation details:* The implementaion is build on top of ”Isolated File System”, which is used by Chrome extension file API as well. Blink already have Isolated File System support. So, I can use it to create FileSystem object in Javascript context with out modify upstream Blink code. Then, I am going to follow the Chrome extesnion file API way to implement Crosswalk native file system. File System Design Chart: Limitations: ======== 1. Linux, Tizen and Android will be supportted. Windows and MacOS are not condidered. 2. Sync file API is not included in this feature. Security consideration: ================= 1. For Linux and Tizen: reply on Crosswalk extension security machanism. 2. For Andoid: WRITE_EXTERNAL_STORAGE and MOUNT_UNMOUNT_FILESYSTEMS need to be declared in the activity manifest. IDL: === /[Supplemental, NoInterfaceObject]/ /interface FileSystem {/ /void //_requestNativeFileSystem_/ <http://www.w3.org/TR/file-system-api/>/(DOMString path, //_FileSystemCallback_/ <http://www.w3.org/TR/file-system-api/>/successCallback, optional //_ErrorCallback_/ <http://www.w3.org/TR/file-system-api/>/errorCallback);/ /};/ Description: Requests a native filesystem in which to store application data.If successful, this function must give access to a native files ystem, as defined above. Paramters: +----------------+--------------------+---------+--------+-----------------------------------+ |Parameter | Type |Nullable |Optional| Description | +----------------+--------------------+---------+--------+-----------------------------------+ |path | DOMString | no | no |The real path on native system | +----------------+--------------------+---------+--------+-----------------------------------+ |successCallback | FileSystemCallback | no | no |The callback that is called when | | | | | |user agent provides a file system | +----------------+--------------------+---------+--------+-----------------------------------+ |errorCallback | ErrorCallback | no | yes |A callback that is called when | | | | | |errors happend, or when the reqeust| | | | | |to obtain the filesystem is denied | +----------------+--------------------+---------+--------+-----------------------------------+ Return Type: void More background: ============== There are two options were discussed before, neither are accepted with reasons. 1. Improve file API in Blink to support out-of-sandbox file access. Abondoneded because of maintainence concern. 2. Implement a new file API that expose the C file API interface. Abondoneded because incompatible with W3C file interfaces. *References:* */[1] /**/_http://www.w3.org/TR/file-system-api/_/* */[2]/**//**/_http://www.w3.org/TR/file-writer-api/_/* */[3] /**/_http://developer.chrome.com/apps/app_storage_/* Thanks, -Shawn
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