diff --git a/chrome/content/zotero/preferences/preferences.js b/chrome/content/zotero/preferences/preferences.js
index bcfaf81759..56968d3ef6 100644
--- a/chrome/content/zotero/preferences/preferences.js
+++ b/chrome/content/zotero/preferences/preferences.js
@@ -130,255 +130,6 @@ function init()
 }
 
 
-function chooseBaseAttachmentPath() {
-	// Get existing base directory
-	var oldBasePath = Zotero.Prefs.get('baseAttachmentPath');
-	if (oldBasePath) {
-		var oldBasePathFile = Components.classes["@mozilla.org/file/local;1"]
-			.createInstance(Components.interfaces.nsILocalFile);
-		try {
-			oldBasePathFile.persistentDescriptor = oldBasePath;
-		}
-		catch (e) {
-			Zotero.debug(e, 1);
-			Components.utils.reportError(e);
-			oldBasePathFile = null;
-		}
-	}
-	
-	//Prompt user to choose new base path
-	var nsIFilePicker = Components.interfaces.nsIFilePicker;
-	var fp = Components.classes["@mozilla.org/filepicker;1"]
-				.createInstance(nsIFilePicker);
-	if (oldBasePathFile) {
-		fp.displayDirectory = oldBasePathFile;
-	}
-	fp.init(window, Zotero.getString('attachmentBasePath.selectDir'), nsIFilePicker.modeGetFolder);
-	fp.appendFilters(nsIFilePicker.filterAll);
-	if (fp.show() != nsIFilePicker.returnOK) {
-		return false;
-	}
-	var newBasePathFile = fp.file;
-	
-	if (oldBasePathFile && oldBasePathFile.equals(newBasePathFile)) {
-		Zotero.debug("Base directory hasn't changed");
-		return false;
-	}
-	
-	// Find all current attachments with relative attachment paths
-	var sql = "SELECT itemID FROM itemAttachments WHERE linkMode=? AND path LIKE '"
-		+ Zotero.Attachments.BASE_PATH_PLACEHOLDER  + "%'";
-	var params = [Zotero.Attachments.LINK_MODE_LINKED_FILE];
-	var oldRelativeAttachmentIDs = Zotero.DB.columnQuery(sql, params) || [];
-	
-	//Find all attachments on the new base path
-	var sql = "SELECT itemID FROM itemAttachments WHERE linkMode=?";
-	var params = [Zotero.Attachments.LINK_MODE_LINKED_FILE];
-	var allAttachments = Zotero.DB.columnQuery(sql,params);
-	var newAttachmentPaths = {};
-	var numNewAttachments = 0;
-	var numOldAttachments = 0;
-	var attachmentFile = Components.classes["@mozilla.org/file/local;1"]
-		.createInstance(Components.interfaces.nsILocalFile);
-	for (let i=0; i<allAttachments.length; i++) {
-		let attachmentID = allAttachments[i];
-		
-		try {
-			let attachment = Zotero.Items.get(attachmentID);
-			attachmentFile.persistentDescriptor = attachment.attachmentPath;
-		}
-		catch (e) {
-			// Don't deal with bad attachment paths. Just skip them.
-			continue;
-		}
-		
-		// If a file with the same relative path exists within the new base directory,
-		// don't touch the attachment, since it will continue to work
-		let isExistingRelativeAttachment = oldRelativeAttachmentIDs.indexOf(attachmentID) != -1;
-		if (isExistingRelativeAttachment && oldBasePathFile) {
-			let relFile = attachmentFile.clone();
-			let relPath = attachmentFile.getRelativeDescriptor(oldBasePathFile);
-			relFile.setRelativeDescriptor(newBasePathFile, relPath);
-			if (relFile.exists()) {
-				numNewAttachments++;
-				continue;
-			}
-		}
-		
-		// Files within the new base directory need to be updated to use
-		// relative paths (or, if the new base directory is an ancestor or
-		// descendant of the old one, new relative paths)
-		if (Zotero.File.directoryContains(newBasePathFile, attachmentFile)) {
-			newAttachmentPaths[attachmentID] = isExistingRelativeAttachment
-				? attachmentFile.persistentDescriptor : null;
-			numNewAttachments++;
-		}
-		// Existing relative attachments not within the new base directory
-		// will be converted to absolute paths
-		else if (isExistingRelativeAttachment && oldBasePathFile) {
-			newAttachmentPaths[attachmentID] = attachmentFile.persistentDescriptor;
-			numOldAttachments++;
-		}
-	}
-	
-	//Confirm change of the base path
-	var ps = Components.classes["@mozilla.org/embedcomp/prompt-service;1"]
-		.getService(Components.interfaces.nsIPromptService);
-	
-	var chooseStrPrefix = 'attachmentBasePath.chooseNewPath.';
-	var clearStrPrefix = 'attachmentBasePath.clearBasePath.';
-	var title = Zotero.getString(chooseStrPrefix + 'title');
-	var msg1 = Zotero.getString(chooseStrPrefix + 'message') + "\n\n", msg2 = msg3 = "";
-	switch (numNewAttachments) {
-		case 0:
-			break;
-		
-		case 1:
-			msg2 += Zotero.getString(chooseStrPrefix + 'existingAttachments.singular') + " ";
-			break;
-		
-		default:
-			msg2 += Zotero.getString(chooseStrPrefix + 'existingAttachments.plural', numNewAttachments) + " ";
-	}
-	
-	switch (numOldAttachments) {
-		case 0:
-			break;
-		
-		case 1:
-			msg3 += Zotero.getString(clearStrPrefix + 'existingAttachments.singular');
-			break;
-		
-		default:
-			msg3 += Zotero.getString(clearStrPrefix + 'existingAttachments.plural', numOldAttachments);
-	}
-	
-	
-	var buttonFlags = (ps.BUTTON_POS_0) * (ps.BUTTON_TITLE_IS_STRING)
-		+ (ps.BUTTON_POS_1) * (ps.BUTTON_TITLE_CANCEL);
-	var index = ps.confirmEx(
-		null,
-		title,
-		(msg1 + msg2 + msg3).trim(),
-		buttonFlags,
-		Zotero.getString(chooseStrPrefix + 'button'),
-		null,
-		null,
-		null,
-		{}
-	);
-	
-	if (index == 1) {
-		return false;
-	}
-	
-	// Set new data directory
-	Zotero.debug("Setting new base directory");
-	Zotero.Prefs.set('baseAttachmentPath', newBasePathFile.persistentDescriptor);
-	Zotero.Prefs.set('saveRelativeAttachmentPath', true);
-	// Resave all attachments on base path (so that their paths become relative)
-	// and all other relative attachments (so that their paths become absolute)
-	for (let id in newAttachmentPaths) {
-		let attachment = Zotero.Items.get(id);
-		if (newAttachmentPaths[id]) {
-			attachment.attachmentPath = newAttachmentPaths[id];
-			attachment.save();
-		}
-		else {
-			attachment.updateAttachmentPath();
-		}
-	}
-	return newBasePathFile.persistentDescriptor;
-}
-
-function getBaseAttachmentPath(asFile) {
-	var desc = Zotero.Prefs.get('baseAttachmentPath');
-	if (desc == '') {
-		return asFile ? null : '';
-	}
-	
-	var file = Components.classes["@mozilla.org/file/local;1"]
-		.createInstance(Components.interfaces.nsILocalFile);
-	try {
-		file.persistentDescriptor = desc;
-	}
-	catch (e) {
-		return asFile ? null : '';
-	}
-	return asFile ? file : file.path;
-}
-
-function clearBaseAttachmentPath() {
-	// Find all current attachments with relative paths
-	var sql = "SELECT itemID FROM itemAttachments WHERE linkMode=? AND path LIKE '"
-		+ Zotero.Attachments.BASE_PATH_PLACEHOLDER  + "%'";
-	var params = [Zotero.Attachments.LINK_MODE_LINKED_FILE];
-	var relativeAttachmentIDs = Zotero.DB.columnQuery(sql, params) || [];
-	
-	// Prompt for confirmation
-	var ps = Components.classes["@mozilla.org/embedcomp/prompt-service;1"]
-		.getService(Components.interfaces.nsIPromptService);
-	
-	var strPrefix = 'attachmentBasePath.clearBasePath.';
-	var title = Zotero.getString(strPrefix + 'title');
-	var msg = Zotero.getString(strPrefix + 'message');
-	switch (relativeAttachmentIDs.length) {
-		case 0:
-			break;
-		
-		case 1:
-			msg += "\n\n" + Zotero.getString(strPrefix + 'existingAttachments.singular');
-			break;
-		
-		default:
-			msg += "\n\n" + Zotero.getString(strPrefix + 'existingAttachments.plural',
-				relativeAttachmentIDs.length);
-	}
-	
-	var buttonFlags = (ps.BUTTON_POS_0) * (ps.BUTTON_TITLE_IS_STRING)
-		+ (ps.BUTTON_POS_1) * (ps.BUTTON_TITLE_CANCEL);
-	var index = ps.confirmEx(
-		window,
-		title,
-		msg,
-		buttonFlags,
-		Zotero.getString(strPrefix + 'button'),
-		null,
-		null,
-		null,
-		{}
-	);
-	
-	if (index == 1) {
-		return false;
-	}
-	
-	// Disable relative path saving and then resave all relative
-	// attachments so that their absolute paths are stored
-	Zotero.debug('Clearing base directory');
-	Zotero.Prefs.set('saveRelativeAttachmentPath', false);
-	for (var i=0; i<relativeAttachmentIDs.length; i++) {
-		Zotero.Items.get(relativeAttachmentIDs[i]).updateAttachmentPath();
-	}
-	Zotero.Prefs.set('baseAttachmentPath', '');
-}
-
-
-function updateBaseAttachmentPathUI() {
-	var filefield = document.getElementById('baseAttachmentPath');
-	var file = getBaseAttachmentPath(true);
-	filefield.file = file;
-	if (file) {
-		filefield.label = file.path;
-	}
-	else {
-		filefield.label = '';
-	}
-	
-	document.getElementById('resetBasePath').disabled = !Zotero.Prefs.get('baseAttachmentPath');
-}
-
-
 function onDataDirLoad() {
 	var path = document.getElementById('dataDirPath');
 	var useDataDir = Zotero.Prefs.get('useDataDir');
@@ -2266,4 +2017,257 @@ function openInViewer(uri, newTab) {
 			var win = ww.openWindow(null, uri, null, features + ",width=775,height=575", null);
 		}
 	}
+}
+
+
+Zotero_Preferences.Attachment_Base_Directory = {
+	choosePath: function () {
+		// Get existing base directory
+		var oldBasePath = Zotero.Prefs.get('baseAttachmentPath');
+		if (oldBasePath) {
+			var oldBasePathFile = Components.classes["@mozilla.org/file/local;1"]
+				.createInstance(Components.interfaces.nsILocalFile);
+			try {
+				oldBasePathFile.persistentDescriptor = oldBasePath;
+			}
+			catch (e) {
+				Zotero.debug(e, 1);
+				Components.utils.reportError(e);
+				oldBasePathFile = null;
+			}
+		}
+		
+		//Prompt user to choose new base path
+		var nsIFilePicker = Components.interfaces.nsIFilePicker;
+		var fp = Components.classes["@mozilla.org/filepicker;1"]
+					.createInstance(nsIFilePicker);
+		if (oldBasePathFile) {
+			fp.displayDirectory = oldBasePathFile;
+		}
+		fp.init(window, Zotero.getString('attachmentBasePath.selectDir'), nsIFilePicker.modeGetFolder);
+		fp.appendFilters(nsIFilePicker.filterAll);
+		if (fp.show() != nsIFilePicker.returnOK) {
+			return false;
+		}
+		var newBasePathFile = fp.file;
+		
+		if (oldBasePathFile && oldBasePathFile.equals(newBasePathFile)) {
+			Zotero.debug("Base directory hasn't changed");
+			return false;
+		}
+		
+		// Find all current attachments with relative attachment paths
+		var sql = "SELECT itemID FROM itemAttachments WHERE linkMode=? AND path LIKE '"
+			+ Zotero.Attachments.BASE_PATH_PLACEHOLDER  + "%'";
+		var params = [Zotero.Attachments.LINK_MODE_LINKED_FILE];
+		var oldRelativeAttachmentIDs = Zotero.DB.columnQuery(sql, params) || [];
+		
+		//Find all attachments on the new base path
+		var sql = "SELECT itemID FROM itemAttachments WHERE linkMode=?";
+		var params = [Zotero.Attachments.LINK_MODE_LINKED_FILE];
+		var allAttachments = Zotero.DB.columnQuery(sql,params);
+		var newAttachmentPaths = {};
+		var numNewAttachments = 0;
+		var numOldAttachments = 0;
+		var attachmentFile = Components.classes["@mozilla.org/file/local;1"]
+			.createInstance(Components.interfaces.nsILocalFile);
+		for (let i=0; i<allAttachments.length; i++) {
+			let attachmentID = allAttachments[i];
+			
+			try {
+				let attachment = Zotero.Items.get(attachmentID);
+				attachmentFile.persistentDescriptor = attachment.attachmentPath;
+			}
+			catch (e) {
+				// Don't deal with bad attachment paths. Just skip them.
+				continue;
+			}
+			
+			// If a file with the same relative path exists within the new base directory,
+			// don't touch the attachment, since it will continue to work
+			let isExistingRelativeAttachment = oldRelativeAttachmentIDs.indexOf(attachmentID) != -1;
+			if (isExistingRelativeAttachment && oldBasePathFile) {
+				let relFile = attachmentFile.clone();
+				let relPath = attachmentFile.getRelativeDescriptor(oldBasePathFile);
+				relFile.setRelativeDescriptor(newBasePathFile, relPath);
+				if (relFile.exists()) {
+					numNewAttachments++;
+					continue;
+				}
+			}
+			
+			// Files within the new base directory need to be updated to use
+			// relative paths (or, if the new base directory is an ancestor or
+			// descendant of the old one, new relative paths)
+			if (Zotero.File.directoryContains(newBasePathFile, attachmentFile)) {
+				newAttachmentPaths[attachmentID] = isExistingRelativeAttachment
+					? attachmentFile.persistentDescriptor : null;
+				numNewAttachments++;
+			}
+			// Existing relative attachments not within the new base directory
+			// will be converted to absolute paths
+			else if (isExistingRelativeAttachment && oldBasePathFile) {
+				newAttachmentPaths[attachmentID] = attachmentFile.persistentDescriptor;
+				numOldAttachments++;
+			}
+		}
+		
+		//Confirm change of the base path
+		var ps = Components.classes["@mozilla.org/embedcomp/prompt-service;1"]
+			.getService(Components.interfaces.nsIPromptService);
+		
+		var chooseStrPrefix = 'attachmentBasePath.chooseNewPath.';
+		var clearStrPrefix = 'attachmentBasePath.clearBasePath.';
+		var title = Zotero.getString(chooseStrPrefix + 'title');
+		var msg1 = Zotero.getString(chooseStrPrefix + 'message') + "\n\n", msg2 = msg3 = "";
+		switch (numNewAttachments) {
+			case 0:
+				break;
+			
+			case 1:
+				msg2 += Zotero.getString(chooseStrPrefix + 'existingAttachments.singular') + " ";
+				break;
+			
+			default:
+				msg2 += Zotero.getString(chooseStrPrefix + 'existingAttachments.plural', numNewAttachments) + " ";
+		}
+		
+		switch (numOldAttachments) {
+			case 0:
+				break;
+			
+			case 1:
+				msg3 += Zotero.getString(clearStrPrefix + 'existingAttachments.singular');
+				break;
+			
+			default:
+				msg3 += Zotero.getString(clearStrPrefix + 'existingAttachments.plural', numOldAttachments);
+		}
+		
+		
+		var buttonFlags = (ps.BUTTON_POS_0) * (ps.BUTTON_TITLE_IS_STRING)
+			+ (ps.BUTTON_POS_1) * (ps.BUTTON_TITLE_CANCEL);
+		var index = ps.confirmEx(
+			null,
+			title,
+			(msg1 + msg2 + msg3).trim(),
+			buttonFlags,
+			Zotero.getString(chooseStrPrefix + 'button'),
+			null,
+			null,
+			null,
+			{}
+		);
+		
+		if (index == 1) {
+			return false;
+		}
+		
+		// Set new data directory
+		Zotero.debug("Setting new base directory");
+		Zotero.Prefs.set('baseAttachmentPath', newBasePathFile.persistentDescriptor);
+		Zotero.Prefs.set('saveRelativeAttachmentPath', true);
+		// Resave all attachments on base path (so that their paths become relative)
+		// and all other relative attachments (so that their paths become absolute)
+		for (let id in newAttachmentPaths) {
+			let attachment = Zotero.Items.get(id);
+			if (newAttachmentPaths[id]) {
+				attachment.attachmentPath = newAttachmentPaths[id];
+				attachment.save();
+			}
+			else {
+				attachment.updateAttachmentPath();
+			}
+		}
+		return newBasePathFile.persistentDescriptor;
+	},
+	
+	
+	getPath: function (asFile) {
+		var desc = Zotero.Prefs.get('baseAttachmentPath');
+		if (desc == '') {
+			return asFile ? null : '';
+		}
+		
+		var file = Components.classes["@mozilla.org/file/local;1"]
+			.createInstance(Components.interfaces.nsILocalFile);
+		try {
+			file.persistentDescriptor = desc;
+		}
+		catch (e) {
+			return asFile ? null : '';
+		}
+		return asFile ? file : file.path;
+	},
+	
+	
+	clearPath: function () {
+		// Find all current attachments with relative paths
+		var sql = "SELECT itemID FROM itemAttachments WHERE linkMode=? AND path LIKE '"
+			+ Zotero.Attachments.BASE_PATH_PLACEHOLDER  + "%'";
+		var params = [Zotero.Attachments.LINK_MODE_LINKED_FILE];
+		var relativeAttachmentIDs = Zotero.DB.columnQuery(sql, params) || [];
+		
+		// Prompt for confirmation
+		var ps = Components.classes["@mozilla.org/embedcomp/prompt-service;1"]
+			.getService(Components.interfaces.nsIPromptService);
+		
+		var strPrefix = 'attachmentBasePath.clearBasePath.';
+		var title = Zotero.getString(strPrefix + 'title');
+		var msg = Zotero.getString(strPrefix + 'message');
+		switch (relativeAttachmentIDs.length) {
+			case 0:
+				break;
+			
+			case 1:
+				msg += "\n\n" + Zotero.getString(strPrefix + 'existingAttachments.singular');
+				break;
+			
+			default:
+				msg += "\n\n" + Zotero.getString(strPrefix + 'existingAttachments.plural',
+					relativeAttachmentIDs.length);
+		}
+		
+		var buttonFlags = (ps.BUTTON_POS_0) * (ps.BUTTON_TITLE_IS_STRING)
+			+ (ps.BUTTON_POS_1) * (ps.BUTTON_TITLE_CANCEL);
+		var index = ps.confirmEx(
+			window,
+			title,
+			msg,
+			buttonFlags,
+			Zotero.getString(strPrefix + 'button'),
+			null,
+			null,
+			null,
+			{}
+		);
+		
+		if (index == 1) {
+			return false;
+		}
+		
+		// Disable relative path saving and then resave all relative
+		// attachments so that their absolute paths are stored
+		Zotero.debug('Clearing base directory');
+		Zotero.Prefs.set('saveRelativeAttachmentPath', false);
+		for (var i=0; i<relativeAttachmentIDs.length; i++) {
+			Zotero.Items.get(relativeAttachmentIDs[i]).updateAttachmentPath();
+		}
+		Zotero.Prefs.set('baseAttachmentPath', '');
+	},
+	
+	
+	updateUI: function () {
+		var filefield = document.getElementById('baseAttachmentPath');
+		var file = this.getPath(true);
+		filefield.file = file;
+		if (file) {
+			filefield.label = file.path;
+		}
+		else {
+			filefield.label = '';
+		}
+		
+		document.getElementById('resetBasePath').disabled = !Zotero.Prefs.get('baseAttachmentPath');
+	}
 }
\ No newline at end of file
diff --git a/chrome/content/zotero/preferences/preferences.xul b/chrome/content/zotero/preferences/preferences.xul
index cdac77516a..33c2f42053 100644
--- a/chrome/content/zotero/preferences/preferences.xul
+++ b/chrome/content/zotero/preferences/preferences.xul
@@ -813,19 +813,19 @@ To add a new preference:
 							<label value="&zotero.preferences.attachmentBaseDir.basePath;"/>
 							<filefield id="baseAttachmentPath"
 								preference="pref-baseAttachmentPath"
-								onsyncfrompreference="updateBaseAttachmentPathUI()"
+								onsyncfrompreference="Zotero_Preferences.Attachment_Base_Directory.updateUI()"
 								preference-editable="true"
 								readonly="true"
 								flex="1"
 								tabindex="-1"/>
 							<button label="&zotero.preferences.attachmentBaseDir.selectBasePath;"
-								oncommand="chooseBaseAttachmentPath()"/>
+								oncommand="Zotero_Preferences.Attachment_Base_Directory.choosePath()"/>
 						</hbox>
 						
 						<hbox>
 							<button id="resetBasePath"
 								label="&zotero.preferences.attachmentBaseDir.resetBasePath;"
-								oncommand="clearBaseAttachmentPath()"/>
+								oncommand="Zotero_Preferences.Attachment_Base_Directory.clearPath()"/>
 						</hbox>
 						
 					</groupbox>