filesaver.js

/* FileSaver.js
 * A saveAs() FileSaver implementation.
 * 2013-10-21
 *
 * By Eli Grey, http://eligrey.com
 * License: X11/MIT
 *   See LICENSE.md
 */

/* LICENSE.md:
This software is licensed under the MIT/X11 license.

MIT/X11 license
---------------

Copyright © 2011 [Eli Grey][1].

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.


  [1]: http://eligrey.com*/


/*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
  || (typeof navigator !== 'undefined' && navigator.msSaveOrOpenBlob && navigator.msSaveOrOpenBlob.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 =  !view.externalHost && "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;
					} else {
                        window.open(object_url, "_blank");
                    }
					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);
				// FF for Android has a nasty garbage collection mechanism
				// that turns all objects that are not pure javascript into 'deadObject'
				// this means `doc` and `save_link` are unusable and need to be recreated
				// `view` is usable though:
				doc = view.document;
				save_link = doc.createElementNS("http://www.w3.org/1999/xhtml", "a");
				save_link.href = object_url;
				save_link.download = name;
				var event = doc.createEvent("MouseEvents");
				event.initMouseEvent(
					"click", true, false, view, 0, 0, 0, 0, 0
					, false, false, false, false, 0, null
				);
				save_link.dispatchEvent(event);
				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;
			}
			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;
}(this.self || this.window || this.content));
// `self` is undefined in Firefox for Android content script context
// while `this` is nsIContentFrameMessageManager
// with an attribute `content` that corresponds to the window

if (typeof module !== 'undefined') module.exports = saveAs;