FileSaver.js

/* FileSaver.js
 * A saveAs() FileSaver implementation.
 * 1.2.2
 *
 * By Eli Grey, http://eligrey.com
 * License: MIT
 *   See https://github.com/eligrey/FileSaver.js/blob/master/LICENSE.md
 */

/*global self */
/*jslint bitwise: true, indent: 4, laxbreak: true, laxcomma: true, smarttabs: true, plusplus: true */

/*! @source http://purl.eligrey.com/github/FileSaver.js/blob/master/FileSaver.js */

var saveAs = saveAs || (function(view) {
  "use strict";
  // IE <10 is explicitly unsupported
  if (typeof navigator !== "undefined" && /MSIE [1-9]\./.test(navigator.userAgent)) {
    return;
  }
  var
  doc = view.document
  // only get URL when necessary in case Blob.js hasn't overridden it yet
  , get_URL = function() {
    return 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 = new MouseEvent("click");
    node.dispatchEvent(event);
  }
  , is_safari = /Version\/[\d\.]+.*Safari/.test(navigator.userAgent)
  , 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
  // the Blob API is fundamentally broken as there is no "downloadfinished" event to subscribe to
  , arbitrary_revoke_timeout = 1000 * 40 // in ms
  , revoke = function(file) {
    var revoker = function() {
      if (typeof file === "string") { // file is an object URL
	get_URL().revokeObjectURL(file);
      } else { // file is a File
	file.remove();
      }
    };
    /* // Take note W3C:
       var
       uri = typeof file === "string" ? file : file.toURL()
       , revoker = function(evt) {
       // idealy DownloadFinishedEvent.data would be the URL requested
       if (evt.data === uri) {
       if (typeof file === "string") { // file is an object URL
       get_URL().revokeObjectURL(file);
       } else { // file is a File
       file.remove();
       }
       }
       }
       ;
       view.addEventListener("downloadfinished", revoker);
    */
    setTimeout(revoker, arbitrary_revoke_timeout);
  }
  , 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);
	}
      }
    }
  }
  , auto_bom = function(blob) {
    // prepend BOM for UTF-8 XML and text/* types (including HTML)
    // note: your browser will automatically convert UTF-16 U+FEFF to EF BB BF
    if (/^\s*(?:text\/\S*|application\/xml|\S*\/\S*\+xml)\s*;.*charset\s*=\s*utf-8/i.test(blob.type)) {
      return new Blob([String.fromCharCode(0xFEFF), blob], {type: blob.type});
    }
    return blob;
  }
  , FileSaver = function(blob, name, no_auto_bom) {
    if (!no_auto_bom) {
      blob = auto_bom(blob);
    }
    // First try a.download, then web filesystem, then object URLs
    var
    filesaver = this
    , type = blob.type
    , blob_changed = false
    , object_url
    , target_view
    , dispatch_all = function() {
      dispatch(filesaver, "writestart progress write writeend".split(" "));
    }
    // on any filesys errors revert to saving with object URLs
    , fs_error = function() {
      if (target_view && is_safari && typeof FileReader !== "undefined") {
	// Safari doesn't allow downloading of blob urls
	var reader = new FileReader();
	reader.onloadend = function() {
	  var base64Data = reader.result;
	  target_view.location.href = "data:attachment/file" + base64Data.slice(base64Data.search(/[,;]/));
	  filesaver.readyState = filesaver.DONE;
	  dispatch_all();
	};
	reader.readAsDataURL(blob);
	filesaver.readyState = filesaver.INIT;
	return;
      }
      // don't create more object URLs than needed
      if (blob_changed || !object_url) {
	object_url = get_URL().createObjectURL(blob);
      }
      if (target_view) {
	target_view.location.href = object_url;
      } else {
	var new_tab = view.open(object_url, "_blank");
	if (new_tab === undefined && is_safari) {
	  // Apple does not allow window.open, see https://developer.apple.com/library/safari/documentation/Tools/Conceptual/SafariExtensionGuide/WorkingwithWindowsandTabs/WorkingwithWindowsandTabs.html
	  view.location.href = object_url;
	}
      }
      filesaver.readyState = filesaver.DONE;
      dispatch_all();
      revoke(object_url);
    }
    , 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_URL().createObjectURL(blob);
      setTimeout(function() {
	save_link.href = object_url;
	save_link.download = name;
	click(save_link);
	dispatch_all();
	revoke(object_url);
	filesaver.readyState = filesaver.DONE;
      });
      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
    // Update: Google errantly closed 91158, I submitted it again:
    // https://code.google.com/p/chromium/issues/detail?id=389642
    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();
		filesaver.readyState = filesaver.DONE;
		dispatch(filesaver, "writeend", event);
		revoke(file);
	      };
	      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, no_auto_bom) {
    return new FileSaver(blob, name, no_auto_bom);
  }
  ;
  // IE 10+ (native saveAs)
  if (typeof navigator !== "undefined" && navigator.msSaveOrOpenBlob) {
    return function(blob, name, no_auto_bom) {
      if (!no_auto_bom) {
	blob = auto_bom(blob);
      }
      return navigator.msSaveOrOpenBlob(blob, name || "download");
    };
  }

  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;

  return saveAs;
}(
  typeof self !== "undefined" && self
    || typeof window !== "undefined" && 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) {
  module.exports.saveAs = saveAs;
} else if ((typeof define !== "undefined" && define !== null) && (define.amd !== null)) {
  define([], function() {
    return saveAs;
  });
}