lib/FileSaver.js
/* FileSaver.js
* A saveAs() FileSaver implementation.
* 2013-01-23
*
* By Eli Grey, http://eligrey.com
* License: X11/MIT
* See LICENSE.md
*/
/*global self */
/*jslint bitwise: true, regexp: true, confusion: true, es5: true, vars: true, white: true,
plusplus: true */
/*! @source http://purl.eligrey.com/github/FileSaver.js/blob/master/FileSaver.js */
var saveAs = saveAs
|| (navigator.msSaveBlob && navigator.msSaveBlob.bind(navigator))
|| (function(view) {
"use strict";
var
doc = view.document
// only get URL when necessary in case BlobBuilder.js hasn't overridden it yet
, get_URL = function() {
return view.URL || view.webkitURL || view;
}
, URL = view.URL || view.webkitURL || view
, save_link = doc.createElementNS("http://www.w3.org/1999/xhtml", "a")
, can_use_save_link = "download" in save_link
, click = function(node) {
var event = doc.createEvent("MouseEvents");
event.initMouseEvent(
"click", true, false, view, 0, 0, 0, 0, 0
, false, false, false, false, 0, null
);
node.dispatchEvent(event);
}
, webkit_req_fs = view.webkitRequestFileSystem
, req_fs = view.requestFileSystem || webkit_req_fs || view.mozRequestFileSystem
, throw_outside = function (ex) {
(view.setImmediate || view.setTimeout)(function() {
throw ex;
}, 0);
}
, force_saveable_type = "application/octet-stream"
, fs_min_size = 0
, deletion_queue = []
, process_deletion_queue = function() {
var i = deletion_queue.length;
while (i--) {
var file = deletion_queue[i];
if (typeof file === "string") { // file is an object URL
URL.revokeObjectURL(file);
} else { // file is a File
file.remove();
}
}
deletion_queue.length = 0; // clear queue
}
, dispatch = function(filesaver, event_types, event) {
event_types = [].concat(event_types);
var i = event_types.length;
while (i--) {
var listener = filesaver["on" + event_types[i]];
if (typeof listener === "function") {
try {
listener.call(filesaver, event || filesaver);
} catch (ex) {
throw_outside(ex);
}
}
}
}
, FileSaver = function(blob, name) {
// First try a.download, then web filesystem, then object URLs
var
filesaver = this
, type = blob.type
, blob_changed = false
, object_url
, target_view
, get_object_url = function() {
var object_url = get_URL().createObjectURL(blob);
deletion_queue.push(object_url);
return object_url;
}
, dispatch_all = function() {
dispatch(filesaver, "writestart progress write writeend".split(" "));
}
// on any filesys errors revert to saving with object URLs
, fs_error = function() {
// don't create more object URLs than needed
if (blob_changed || !object_url) {
object_url = get_object_url(blob);
}
if (target_view) {
target_view.location.href = object_url;
}
filesaver.readyState = filesaver.DONE;
dispatch_all();
}
, abortable = function(func) {
return function() {
if (filesaver.readyState !== filesaver.DONE) {
return func.apply(this, arguments);
}
};
}
, create_if_not_found = {create: true, exclusive: false}
, slice
;
filesaver.readyState = filesaver.INIT;
if (!name) {
name = "download";
}
if (can_use_save_link) {
object_url = get_object_url(blob);
save_link.href = object_url;
save_link.download = name;
click(save_link);
filesaver.readyState = filesaver.DONE;
dispatch_all();
return;
}
// Object and web filesystem URLs have a problem saving in Google Chrome when
// viewed in a tab, so I force save with application/octet-stream
// http://code.google.com/p/chromium/issues/detail?id=91158
if (view.chrome && type && type !== force_saveable_type) {
slice = blob.slice || blob.webkitSlice;
blob = slice.call(blob, 0, blob.size, force_saveable_type);
blob_changed = true;
}
// Since I can't be sure that the guessed media type will trigger a download
// in WebKit, I append .download to the filename.
// https://bugs.webkit.org/show_bug.cgi?id=65440
if (webkit_req_fs && name !== "download") {
name += ".download";
}
if (type === force_saveable_type || webkit_req_fs) {
target_view = view;
} else {
target_view = view.open();
}
if (!req_fs) {
fs_error();
return;
}
fs_min_size += blob.size;
req_fs(view.TEMPORARY, fs_min_size, abortable(function(fs) {
fs.root.getDirectory("saved", create_if_not_found, abortable(function(dir) {
var save = function() {
dir.getFile(name, create_if_not_found, abortable(function(file) {
file.createWriter(abortable(function(writer) {
writer.onwriteend = function(event) {
target_view.location.href = file.toURL();
deletion_queue.push(file);
filesaver.readyState = filesaver.DONE;
dispatch(filesaver, "writeend", event);
};
writer.onerror = function() {
var error = writer.error;
if (error.code !== error.ABORT_ERR) {
fs_error();
}
};
"writestart progress write abort".split(" ").forEach(function(event) {
writer["on" + event] = filesaver["on" + event];
});
writer.write(blob);
filesaver.abort = function() {
writer.abort();
filesaver.readyState = filesaver.DONE;
};
filesaver.readyState = filesaver.WRITING;
}), fs_error);
}), fs_error);
};
dir.getFile(name, {create: false}, abortable(function(file) {
// delete file if it already exists
file.remove();
save();
}), abortable(function(ex) {
if (ex.code === ex.NOT_FOUND_ERR) {
save();
} else {
fs_error();
}
}));
}), fs_error);
}), fs_error);
}
, FS_proto = FileSaver.prototype
, saveAs = function(blob, name) {
return new FileSaver(blob, name);
}
;
FS_proto.abort = function() {
var filesaver = this;
filesaver.readyState = filesaver.DONE;
dispatch(filesaver, "abort");
};
FS_proto.readyState = FS_proto.INIT = 0;
FS_proto.WRITING = 1;
FS_proto.DONE = 2;
FS_proto.error =
FS_proto.onwritestart =
FS_proto.onprogress =
FS_proto.onwrite =
FS_proto.onabort =
FS_proto.onerror =
FS_proto.onwriteend =
null;
view.addEventListener("unload", process_deletion_queue, false);
return saveAs;
}(self));