filesaver.js 6.6 KB

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  1. /* FileSaver.js
  2. * A saveAs() FileSaver implementation.
  3. * 2012-12-11
  4. *
  5. * By Eli Grey, http://eligrey.com
  6. * License: X11/MIT
  7. * See LICENSE.md
  8. */
  9. /*global self */
  10. /*jslint bitwise: true, regexp: true, confusion: true, es5: true, vars: true, white: true,
  11. plusplus: true */
  12. /*! @source http://purl.eligrey.com/github/FileSaver.js/blob/master/FileSaver.js */
  13. var saveAs = saveAs
  14. || (navigator.msSaveOrOpenBlob && navigator.msSaveOrOpenBlob.bind(navigator))
  15. || (function(view) {
  16. "use strict";
  17. var
  18. doc = view.document
  19. // only get URL when necessary in case BlobBuilder.js hasn't overridden it yet
  20. , get_URL = function() {
  21. return view.URL || view.webkitURL || view;
  22. }
  23. , URL = view.URL || view.webkitURL || view
  24. , save_link = doc.createElementNS("http://www.w3.org/1999/xhtml", "a")
  25. , can_use_save_link = "download" in save_link
  26. , click = function(node) {
  27. var event = doc.createEvent("MouseEvents");
  28. event.initMouseEvent(
  29. "click", true, false, view, 0, 0, 0, 0, 0
  30. , false, false, false, false, 0, null
  31. );
  32. return node.dispatchEvent(event); // false if event was cancelled
  33. }
  34. , webkit_req_fs = view.webkitRequestFileSystem
  35. , req_fs = view.requestFileSystem || webkit_req_fs || view.mozRequestFileSystem
  36. , throw_outside = function (ex) {
  37. (view.setImmediate || view.setTimeout)(function() {
  38. throw ex;
  39. }, 0);
  40. }
  41. , force_saveable_type = "application/octet-stream"
  42. , fs_min_size = 0
  43. , deletion_queue = []
  44. , process_deletion_queue = function() {
  45. var i = deletion_queue.length;
  46. while (i--) {
  47. var file = deletion_queue[i];
  48. if (typeof file === "string") { // file is an object URL
  49. URL.revokeObjectURL(file);
  50. } else { // file is a File
  51. file.remove();
  52. }
  53. }
  54. deletion_queue.length = 0; // clear queue
  55. }
  56. , dispatch = function(filesaver, event_types, event) {
  57. event_types = [].concat(event_types);
  58. var i = event_types.length;
  59. while (i--) {
  60. var listener = filesaver["on" + event_types[i]];
  61. if (typeof listener === "function") {
  62. try {
  63. listener.call(filesaver, event || filesaver);
  64. } catch (ex) {
  65. throw_outside(ex);
  66. }
  67. }
  68. }
  69. }
  70. , FileSaver = function(blob, name) {
  71. // First try a.download, then web filesystem, then object URLs
  72. var
  73. filesaver = this
  74. , type = blob.type
  75. , blob_changed = false
  76. , object_url
  77. , target_view
  78. , get_object_url = function() {
  79. var object_url = get_URL().createObjectURL(blob);
  80. deletion_queue.push(object_url);
  81. return object_url;
  82. }
  83. , dispatch_all = function() {
  84. dispatch(filesaver, "writestart progress write writeend".split(" "));
  85. }
  86. // on any filesys errors revert to saving with object URLs
  87. , fs_error = function() {
  88. // don't create more object URLs than needed
  89. if (blob_changed || !object_url) {
  90. object_url = get_object_url(blob);
  91. }
  92. target_view.location.href = object_url;
  93. filesaver.readyState = filesaver.DONE;
  94. dispatch_all();
  95. }
  96. , abortable = function(func) {
  97. return function() {
  98. if (filesaver.readyState !== filesaver.DONE) {
  99. return func.apply(this, arguments);
  100. }
  101. };
  102. }
  103. , create_if_not_found = {create: true, exclusive: false}
  104. , slice
  105. ;
  106. filesaver.readyState = filesaver.INIT;
  107. if (!name) {
  108. name = "download";
  109. }
  110. if (can_use_save_link) {
  111. object_url = get_object_url(blob);
  112. save_link.href = object_url;
  113. save_link.download = name;
  114. if (click(save_link)) {
  115. filesaver.readyState = filesaver.DONE;
  116. dispatch_all();
  117. return;
  118. }
  119. }
  120. // Object and web filesystem URLs have a problem saving in Google Chrome when
  121. // viewed in a tab, so I force save with application/octet-stream
  122. // http://code.google.com/p/chromium/issues/detail?id=91158
  123. if (view.chrome && type && type !== force_saveable_type) {
  124. slice = blob.slice || blob.webkitSlice;
  125. blob = slice.call(blob, 0, blob.size, force_saveable_type);
  126. blob_changed = true;
  127. }
  128. // Since I can't be sure that the guessed media type will trigger a download
  129. // in WebKit, I append .download to the filename.
  130. // https://bugs.webkit.org/show_bug.cgi?id=65440
  131. if (webkit_req_fs && name !== "download") {
  132. name += ".download";
  133. }
  134. if (type === force_saveable_type || webkit_req_fs) {
  135. target_view = view;
  136. } else {
  137. target_view = view.open();
  138. }
  139. if (!req_fs) {
  140. fs_error();
  141. return;
  142. }
  143. fs_min_size += blob.size;
  144. req_fs(view.TEMPORARY, fs_min_size, abortable(function(fs) {
  145. fs.root.getDirectory("saved", create_if_not_found, abortable(function(dir) {
  146. var save = function() {
  147. dir.getFile(name, create_if_not_found, abortable(function(file) {
  148. file.createWriter(abortable(function(writer) {
  149. writer.onwriteend = function(event) {
  150. target_view.location.href = file.toURL();
  151. deletion_queue.push(file);
  152. filesaver.readyState = filesaver.DONE;
  153. dispatch(filesaver, "writeend", event);
  154. };
  155. writer.onerror = function() {
  156. var error = writer.error;
  157. if (error.code !== error.ABORT_ERR) {
  158. fs_error();
  159. }
  160. };
  161. "writestart progress write abort".split(" ").forEach(function(event) {
  162. writer["on" + event] = filesaver["on" + event];
  163. });
  164. writer.write(blob);
  165. filesaver.abort = function() {
  166. writer.abort();
  167. filesaver.readyState = filesaver.DONE;
  168. };
  169. filesaver.readyState = filesaver.WRITING;
  170. }), fs_error);
  171. }), fs_error);
  172. };
  173. dir.getFile(name, {create: false}, abortable(function(file) {
  174. // delete file if it already exists
  175. file.remove();
  176. save();
  177. }), abortable(function(ex) {
  178. if (ex.code === ex.NOT_FOUND_ERR) {
  179. save();
  180. } else {
  181. fs_error();
  182. }
  183. }));
  184. }), fs_error);
  185. }), fs_error);
  186. }
  187. , FS_proto = FileSaver.prototype
  188. , saveAs = function(blob, name) {
  189. return new FileSaver(blob, name);
  190. }
  191. ;
  192. FS_proto.abort = function() {
  193. var filesaver = this;
  194. filesaver.readyState = filesaver.DONE;
  195. dispatch(filesaver, "abort");
  196. };
  197. FS_proto.readyState = FS_proto.INIT = 0;
  198. FS_proto.WRITING = 1;
  199. FS_proto.DONE = 2;
  200. FS_proto.error =
  201. FS_proto.onwritestart =
  202. FS_proto.onprogress =
  203. FS_proto.onwrite =
  204. FS_proto.onabort =
  205. FS_proto.onerror =
  206. FS_proto.onwriteend =
  207. null;
  208. view.addEventListener("unload", process_deletion_queue, false);
  209. return saveAs;
  210. }(self));