https://quizdidaktik.de/google-docs-viewer-linkersteller/daten/js/FileSaver.js

1/*! FileSaver.js
2 *  A saveAs() FileSaver implementation.
3 *  2014-01-24
4 *
5 *  By Eli Grey, http://eligrey.com
6 *  License: X11/MIT
7 *    See LICENSE.md
8 */
9
10/*global self */
11/*jslint bitwise: true, indent: 4, laxbreak: true, laxcomma: true, smarttabs: true, plusplus: true */
12
13/*! @source http://purl.eligrey.com/github/FileSaver.js/blob/master/FileSaver.js */
14
15var saveAs = saveAs
16  // IE 10+ (native saveAs)
17  || (typeof navigator !== "undefined" &&
18      navigator.msSaveOrOpenBlob && navigator.msSaveOrOpenBlob.bind(navigator))
19  // Everyone else
20  || (function(view) {
21	"use strict";
22	// IE <10 is explicitly unsupported
23	if (typeof navigator !== "undefined" &&
24	    /MSIE [1-9]\./.test(navigator.userAgent)) {
25		return;
26	}
27	var
28		  doc = view.document
29		  // only get URL when necessary in case BlobBuilder.js hasn't overridden it yet
30		, get_URL = function() {
31			return view.URL || view.webkitURL || view;
32		}
33		, URL = view.URL || view.webkitURL || view
34		, save_link = doc.createElementNS("http://www.w3.org/1999/xhtml", "a")
35		, can_use_save_link = !view.externalHost && "download" in save_link
36		, click = function(node) {
37			var event = doc.createEvent("MouseEvents");
38			event.initMouseEvent(
39				"click", true, false, view, 0, 0, 0, 0, 0
40				, false, false, false, false, 0, null
41			);
42			node.dispatchEvent(event);
43		}
44		, webkit_req_fs = view.webkitRequestFileSystem
45		, req_fs = view.requestFileSystem || webkit_req_fs || view.mozRequestFileSystem
46		, throw_outside = function(ex) {
47			(view.setImmediate || view.setTimeout)(function() {
48				throw ex;
49			}, 0);
50		}
51		, force_saveable_type = "application/octet-stream"
52		, fs_min_size = 0
53		, deletion_queue = []
54		, process_deletion_queue = function() {
55			var i = deletion_queue.length;
56			while (i--) {
57				var file = deletion_queue[i];
58				if (typeof file === "string") { // file is an object URL
59					URL.revokeObjectURL(file);
60				} else { // file is a File
61					file.remove();
62				}
63			}
64			deletion_queue.length = 0; // clear queue
65		}
66		, dispatch = function(filesaver, event_types, event) {
67			event_types = [].concat(event_types);
68			var i = event_types.length;
69			while (i--) {
70				var listener = filesaver["on" + event_types[i]];
71				if (typeof listener === "function") {
72					try {
73						listener.call(filesaver, event || filesaver);
74					} catch (ex) {
75						throw_outside(ex);
76					}
77				}
78			}
79		}
80		, FileSaver = function(blob, name) {
81			// First try a.download, then web filesystem, then object URLs
82			var
83				  filesaver = this
84				, type = blob.type
85				, blob_changed = false
86				, object_url
87				, target_view
88				, get_object_url = function() {
89					var object_url = get_URL().createObjectURL(blob);
90					deletion_queue.push(object_url);
91					return object_url;
92				}
93				, dispatch_all = function() {
94					dispatch(filesaver, "writestart progress write writeend".split(" "));
95				}
96				// on any filesys errors revert to saving with object URLs
97				, fs_error = function() {
98					// don't create more object URLs than needed
99					if (blob_changed || !object_url) {
100						object_url = get_object_url(blob);
101					}
102					if (target_view) {
103						target_view.location.href = object_url;
104					} else {
105						window.open(object_url, "_blank");
106					}
107					filesaver.readyState = filesaver.DONE;
108					dispatch_all();
109				}
110				, abortable = function(func) {
111					return function() {
112						if (filesaver.readyState !== filesaver.DONE) {
113							return func.apply(this, arguments);
114						}
115					};
116				}
117				, create_if_not_found = {create: true, exclusive: false}
118				, slice
119			;
120			filesaver.readyState = filesaver.INIT;
121			if (!name) {
122				name = "download";
123			}
124			if (can_use_save_link) {
125				object_url = get_object_url(blob);
126				// FF for Android has a nasty garbage collection mechanism
127				// that turns all objects that are not pure javascript into 'deadObject'
128				// this means `doc` and `save_link` are unusable and need to be recreated
129				// `view` is usable though:
130				doc = view.document;
131				save_link = doc.createElementNS("http://www.w3.org/1999/xhtml", "a");
132				save_link.href = object_url;

133				save_link.download = name;
134				var event = doc.createEvent("MouseEvents");
135				event.initMouseEvent(
136					"click", true, false, view, 0, 0, 0, 0, 0
137					, false, false, false, false, 0, null
138				);
139				save_link.dispatchEvent(event);
140				filesaver.readyState = filesaver.DONE;
141				dispatch_all();
142				return;
143			}
144			// Object and web filesystem URLs have a problem saving in Google Chrome when
145			// viewed in a tab, so I force save with application/octet-stream
146			// http://code.google.com/p/chromium/issues/detail?id=91158
147			if (view.chrome && type && type !== force_saveable_type) {
148				slice = blob.slice || blob.webkitSlice;
149				blob = slice.call(blob, 0, blob.size, force_saveable_type);
150				blob_changed = true;
151			}
152			// Since I can't be sure that the guessed media type will trigger a download
153			// in WebKit, I append .download to the filename.
154			// https://bugs.webkit.org/show_bug.cgi?id=65440
155			if (webkit_req_fs && name !== "download") {
156				name += ".download";
157			}
158			if (type === force_saveable_type || webkit_req_fs) {
159				target_view = view;
160			}
161			if (!req_fs) {
162				fs_error();
163				return;
164			}
165			fs_min_size += blob.size;
166			req_fs(view.TEMPORARY, fs_min_size, abortable(function(fs) {
167				fs.root.getDirectory("saved", create_if_not_found, abortable(function(dir) {
168					var save = function() {
169						dir.getFile(name, create_if_not_found, abortable(function(file) {
170							file.createWriter(abortable(function(writer) {
171								writer.onwriteend = function(event) {
172									target_view.location.href = file.toURL();
173									deletion_queue.push(file);
174									filesaver.readyState = filesaver.DONE;
175									dispatch(filesaver, "writeend", event);
176								};
177								writer.onerror = function() {
178									var error = writer.error;
179									if (error.code !== error.ABORT_ERR) {
180										fs_error();
181									}
182								};
183								"writestart progress write abort".split(" ").forEach(function(event) {
184									writer["on" + event] = filesaver["on" + event];
185								});
186								writer.write(blob);
187								filesaver.abort = function() {
188									writer.abort();
189									filesaver.readyState = filesaver.DONE;
190								};
191								filesaver.readyState = filesaver.WRITING;
192							}), fs_error);
193						}), fs_error);
194					};
195					dir.getFile(name, {create: false}, abortable(function(file) {
196						// delete file if it already exists
197						file.remove();
198						save();
199					}), abortable(function(ex) {
200						if (ex.code === ex.NOT_FOUND_ERR) {
201							save();
202						} else {
203							fs_error();
204						}
205					}));
206				}), fs_error);
207			}), fs_error);
208		}
209		, FS_proto = FileSaver.prototype
210		, saveAs = function(blob, name) {
211			return new FileSaver(blob, name);
212		}
213	;
214	FS_proto.abort = function() {
215		var filesaver = this;
216		filesaver.readyState = filesaver.DONE;
217		dispatch(filesaver, "abort");
218	};
219	FS_proto.readyState = FS_proto.INIT = 0;
220	FS_proto.WRITING = 1;
221	FS_proto.DONE = 2;
222
223	FS_proto.error =
224	FS_proto.onwritestart =
225	FS_proto.onprogress =
226	FS_proto.onwrite =
227	FS_proto.onabort =
228	FS_proto.onerror =
229	FS_proto.onwriteend =
230		null;
231
232	view.addEventListener("unload", process_deletion_queue, false);
233	saveAs.unload = function() {
234		process_deletion_queue();
235		view.removeEventListener("unload", process_deletion_queue, false);
236	};
237	return saveAs;
238}(
239	   typeof self !== "undefined" && self
240	|| typeof window !== "undefined" && window
241	|| this.content
242));
243// `self` is undefined in Firefox for Android content script context
244// while `this` is nsIContentFrameMessageManager
245// with an attribute `content` that corresponds to the window
246
247if (typeof module !== "undefined") module.exports = saveAs;