Closes #833, Displays a warning dialog if API key present but library empty

chrome/content/zotero/xpcom/data/library.js

@@ -567,6 +567,15 @@ Zotero.Library.prototype.updateSearches = Zotero.Promise.coroutine(function* ()
 	this._hasSearches = !!(yield Zotero.DB.valueQueryAsync(sql, this.libraryID));
 });
 
+Zotero.Library.prototype.hasItems = Zotero.Promise.coroutine(function* () {
+	if (!this.id) {
+		throw new Error("Library is not saved yet");
+	}
+	let sql = 'SELECT COUNT(*)>0 FROM items WHERE libraryID=?';
+
+	return Zotero.DB.valueQueryAsync(sql, this.libraryID);
+});
+
 Zotero.Library.prototype.hasItem = function (item) {
 	if (!(item instanceof Zotero.Item)) {
 		throw new Error("item must be a Zotero.Item");

chrome/content/zotero/xpcom/sync/syncRunner.js

@@ -136,14 +136,20 @@ Zotero.Sync.Runner_Module = function (options = {}) {
 		
 		try {
 			let client = this.getAPIClient({ apiKey });
-			
 			let keyInfo = yield this.checkAccess(client, options);
-			if (!keyInfo) {
+			
+			let emptyLibraryContinue = yield this.checkEmptyLibrary(keyInfo);
+			if (!emptyLibraryContinue) {
 				this.end();
-				Zotero.debug("Syncing cancelled");
+				Zotero.debug("Syncing cancelled because user library is empty");
 				return false;
 			}
 
+			if (!Zotero.Users.getCurrentUserID()) {
+				Zotero.Users.setCurrentUserID(keyInfo.userID);
+				Zotero.Users.setCurrentUsername(keyInfo.username);
+			}
+
 			let engineOptions = {
 				apiClient: client,
 				caller: this.caller,
@@ -233,6 +239,45 @@ Zotero.Sync.Runner_Module = function (options = {}) {
 	});
 
 
+	// Prompt if library empty and there is no userID stored
+	this.checkEmptyLibrary = Zotero.Promise.coroutine(function* (keyInfo) {
+		let library = Zotero.Libraries.userLibrary;
+		let userID = Zotero.Users.getCurrentUserID();
+
+		if (!userID) {
+			let hasItems = yield library.hasItems();
+			if (!hasItems) {
+				let ps = Services.prompt;
+				let index = ps.confirmEx(
+					null,
+					Zotero.getString('general.warning'),
+					Zotero.getString('sync.warning.emptyLibrary', [keyInfo.username, Zotero.clientName]) + "\n\n"
+						+ Zotero.getString('sync.warning.existingDataElsewhere', Zotero.clientName),
+					(ps.BUTTON_POS_0 * ps.BUTTON_TITLE_IS_STRING) 
+						+ (ps.BUTTON_POS_1 * ps.BUTTON_TITLE_CANCEL)
+						+ (ps.BUTTON_POS_2 * ps.BUTTON_TITLE_IS_STRING),
+					Zotero.getString('sync.sync'),
+					null, 
+					Zotero.getString('dataDir.changeDataDirectory'), 
+					null, {}
+				);
+				if (index == 1) {
+					return false;
+				}
+				else if (index == 2) {
+					var win = Services.wm.getMostRecentWindow("navigator:browser");
+					win.openDialog("chrome://zotero/content/preferences/preferences.xul", null, null, {
+						pane: 'zotero-prefpane-advanced',
+						tabIndex: 1
+					});
+					return false;
+				}
+			}
+		}
+		return true;
+	});
+	
+	
 	this.checkLibraries = Zotero.Promise.coroutine(function* (client, options, keyInfo, libraries = []) {
 		var access = keyInfo.access;
 		

chrome/locale/en-US/zotero/zotero.properties

@@ -112,6 +112,7 @@ dataDir.notFound						= The Zotero data directory could not be found.
 dataDir.previousDir					= Previous directory:
 dataDir.useProfileDir				= Use %S profile directory
 dataDir.selectDir					= Select a Zotero data directory
+dataDir.changeDataDirectory 		= Change Data Directory…
 dataDir.unsafeLocation.selected.dropbox = Choosing a data directory within Dropbox may corrupt your database.
 dataDir.unsafeLocation.selected.useAnyway = Use this directory anyway?
 dataDir.unsafeLocation.existing.dropbox = Your Zotero data directory is within Dropbox, which may lead to data corruption.
@@ -828,6 +829,8 @@ sync.localDataWillBeCombined		= If you continue, local Zotero data will be combi
 sync.localGroupsWillBeRemoved1		= Local groups, including any with changed items, will also be removed from this computer.
 sync.avoidCombiningData				= To avoid combining data, revert to the '%S' account or use the Reset options in the Sync pane of the Zotero preferences.
 sync.unlinkWarning					= Are you sure you want to unlink this account?\n\n%S will no longer sync your data, but your data will remain locally.
+sync.warning.emptyLibrary			= You are about to sync the ‘%1$S’ account to an empty %2$S database. This could happen if you removed your previous %2$S database or if the location of your data directory changed.
+sync.warning.existingDataElsewhere  = If your %S data exists elsewhere on your computer, you should move it to your current data directory or change your data directory location to point to the existing data.
 
 sync.conflict.autoChange.alert			= One or more locally deleted Zotero %S have been modified remotely since the last sync.
 sync.conflict.autoChange.log			= A Zotero %S has changed both locally and remotely since the last sync:

test/tests/libraryTest.js

@@ -256,6 +256,39 @@ describe("Zotero.Library", function() {
 			assert.isFalse(library.hasSearches());
 		})
 	});
+	describe("#hasItems()", function() {
+		it("should throw if called before saving a library", function* () {
+			let library = new Zotero.Library();
+			try {
+				yield library.hasItems();
+				assert.isFalse(true, "Library#hasItems did not throw an error");
+			} catch (e) {
+				assert.ok(e);
+			}
+		});
+		it("should stay up to date as items are added and removed", function* () {
+			let library = yield createGroup({ editable: true });
+			let libraryID = library.libraryID;
+			var hasItems = yield library.hasItems();
+			assert.isFalse(hasItems);
+
+			let i1 = yield createDataObject('item', { libraryID });
+			hasItems = yield library.hasItems();
+			assert.isTrue(hasItems);
+
+			let i2 = yield createDataObject('item', { libraryID });
+			hasItems = yield library.hasItems();
+			assert.isTrue(hasItems);
+
+			yield i1.eraseTx();
+			hasItems = yield library.hasItems();
+			assert.isTrue(hasItems);
+
+			yield i2.eraseTx();
+			hasItems = yield library.hasItems();
+			assert.isFalse(hasItems);
+		});
+	});
 	describe("#updateLastSyncTime()", function() {
 		it("should set sync time to current time", function* () {
 			let group = yield createGroup();