Add support for downloading files

We were re-using the `tw-save-wiki` message both for saving the current
wiki and downloading a new wiki. Now we’ll use the separate
`tw-download-file` message for downloading.

Fixes #236

core/modules/savers/andtidwiki.js

@@ -15,7 +15,11 @@ Handles saving changes via the AndTidWiki Android app
 var AndTidWiki = function(wiki) {
 };
 
-AndTidWiki.prototype.save = function(text,callback) {
+AndTidWiki.prototype.save = function(text,method,callback) {
+	// Bail out unless this is a save (rather than a download)
+	if(method !== "save") {
+		return false;
+	}
 	// Get the pathname of this document
 	var pathname = decodeURIComponent(document.location.toString());
 	// Strip the file://

core/modules/savers/download.js

@@ -18,7 +18,7 @@ Select the appropriate saver module and set it up
 var DownloadSaver = function(wiki) {
 };
 
-DownloadSaver.prototype.save = function(text) {
+DownloadSaver.prototype.save = function(text,method,callback) {
 	// Get the current filename
 	var filename = "tiddlywiki.html",
 		p = document.location.pathname.lastIndexOf("/");

core/modules/savers/manualdownload.js

@@ -21,7 +21,7 @@ Select the appropriate saver module and set it up
 var ManualDownloadSaver = function(wiki) {
 };
 
-ManualDownloadSaver.prototype.save = function(text) {
+ManualDownloadSaver.prototype.save = function(text,method,callback) {
 	$tw.modal.display(downloadInstructionsTitle,{
 		downloadLink: "data:text/html," + encodeURIComponent(text)
 	});

core/modules/savers/msdownload.js

@@ -18,7 +18,7 @@ Select the appropriate saver module and set it up
 var MsDownloadSaver = function(wiki) {
 };
 
-MsDownloadSaver.prototype.save = function(text) {
+MsDownloadSaver.prototype.save = function(text,method,callback) {
 	// Get the current filename
 	var filename = "tiddlywiki.html",
 		p = document.location.pathname.lastIndexOf("/");

core/modules/savers/tiddlyfox.js

@@ -15,7 +15,11 @@ Handles saving changes via the TiddlyFox file extension
 var TiddlyFoxSaver = function(wiki) {
 };
 
-TiddlyFoxSaver.prototype.save = function(text,callback) {
+TiddlyFoxSaver.prototype.save = function(text,method,callback) {
+	// Bail out unless this is a save (rather than a download)
+	if(method !== "save") {
+		return false;
+	}
 	var messageBox = document.getElementById("tiddlyfox-message-box");
 	if(messageBox) {
 		// Get the pathname of this document

core/modules/savers/twedit.js

@@ -15,7 +15,11 @@ Handles saving changes via the TWEdit iOS app
 var TWEditSaver = function(wiki) {
 };
 
-TWEditSaver.prototype.save = function(text,callback) {
+TWEditSaver.prototype.save = function(text,method,callback) {
+	// Bail out unless this is a save (rather than a download)
+	if(method !== "save") {
+		return false;
+	}
 	// Bail if we're not running under TWEdit
 	if(typeof DeviceInfo !== "object") {
 		return false;

core/modules/savers/upload.js

@@ -21,7 +21,11 @@ var UploadSaver = function(wiki) {
 	this.wiki = wiki;
 };
 
-UploadSaver.prototype.save = function(text,callback) {
+UploadSaver.prototype.save = function(text,method,callback) {
+	// Bail out unless this is a save (rather than a download)
+	if(method !== "save") {
+		return false;
+	}
 	// Get the various parameters we need
 	var backupDir = ".",
 		username = this.wiki.getTextReference("$:/UploadName"),