Internal Refactoring: Move MySQL Help viewer into own xib with own controller

9 files changed, 876 insertions, 558 deletions

diff --git a/Source/SPCustomQuery.h b/Source/SPCustomQuery.h
index 24695ba2..f06b63dc 100644
--- a/Source/SPCustomQuery.h
+++ b/Source/SPCustomQuery.h
@@ -31,17 +31,6 @@
 
 #import "SPDatabaseContentViewDelegate.h"
 
-#import <WebKit/WebKit.h>
-
-#define SP_HELP_TOC_SEARCH_STRING @"contents"
-#define SP_HELP_SEARCH_IN_MYSQL   0
-#define SP_HELP_SEARCH_IN_PAGE    1
-#define SP_HELP_SEARCH_IN_WEB     2
-#define SP_HELP_GOBACK_BUTTON     0
-#define SP_HELP_SHOW_TOC_BUTTON   1
-#define SP_HELP_GOFORWARD_BUTTON  2
-#define SP_HELP_NOT_AVAILABLE     @"__no_help_available"
-
 #define SP_SAVE_ALL_FAVORTITE_MENUITEM_TAG       100001
 #define SP_SAVE_SELECTION_FAVORTITE_MENUITEM_TAG 100000
 #define SP_FAVORITE_HEADER_MENUITEM_TAG          200000
@@ -122,12 +111,6 @@
 #ifndef SP_CODA
 	IBOutlet NSMenuItem *previousHistoryMenuItem;
 	IBOutlet NSMenuItem *nextHistoryMenuItem;
-	IBOutlet NSWindow *helpWebViewWindow;
-	IBOutlet WebView *helpWebView;
-	IBOutlet NSSearchField *helpSearchField;
-	IBOutlet NSSearchFieldCell *helpSearchFieldCell;
-	IBOutlet NSSegmentedControl *helpNavigator;
-	IBOutlet NSSegmentedControl *helpTargetSelector;
 #endif
 
 	IBOutlet NSButton *queryInfoButton;
@@ -145,17 +128,10 @@
 	NSArray *currentQueryRanges;
 	BOOL currentQueryBeforeCaret;
 
-	NSString *mySQLversion;
 	NSTableColumn *sortColumn;
 
 	NSUInteger queryStartPosition;
 
-#ifndef SP_CODA
-	NSUInteger helpTarget;
-	WebHistory *helpHistory;
-	NSString *helpHTMLTemplate;
-#endif
-
 	SPDataStorage *resultData;
 	pthread_mutex_t resultDataLock;
 	NSArray *cqColumnDefinition;
@@ -213,17 +189,6 @@
 - (IBAction)chooseQueryHistory:(id)sender;
 - (IBAction)closeSheet:(id)sender;
 - (IBAction)gearMenuItemSelected:(id)sender;
-#ifndef SP_CODA
-- (IBAction)showHelpForCurrentWord:(id)sender;
-- (IBAction)showHelpForSearchString:(id)sender;
-- (IBAction)helpSegmentDispatcher:(id)sender;
-- (IBAction)helpTargetDispatcher:(id)sender;
-- (IBAction)helpSearchFindNextInPage:(id)sender;
-- (IBAction)helpSearchFindPreviousInPage:(id)sender;
-- (IBAction)helpSelectHelpTargetMySQL:(id)sender;
-- (IBAction)helpSelectHelpTargetPage:(id)sender;
-- (IBAction)helpSelectHelpTargetWeb:(id)sender;
-#endif
 - (IBAction)filterQueryFavorites:(id)sender;
 - (IBAction)filterQueryHistory:(id)sender;
 - (IBAction)saveQueryHistory:(id)sender;
@@ -268,11 +233,6 @@
 #ifndef SP_CODA
 // MySQL Help
 - (void)showAutoHelpForCurrentWord:(id)sender;
-- (NSString *)getHTMLformattedMySQLHelpFor:(NSString *)searchString calledByAutoHelp:(BOOL)autoHelp;
-- (void)showHelpFor:(NSString *)aString addToHistory:(BOOL)addToHistory calledByAutoHelp:(BOOL)autoHelp;
-- (void)helpTargetValidation;
-- (void)openMySQLonlineDocumentationWithString:(NSString *)searchString;
-- (NSWindow *)helpWebViewWindow;
 #endif
 - (void)setMySQLversion:(NSString *)theVersion;
 
diff --git a/Source/SPCustomQuery.m b/Source/SPCustomQuery.m
index e8c1d6ad..62ff3e18 100644
--- a/Source/SPCustomQuery.m
+++ b/Source/SPCustomQuery.m
@@ -61,6 +61,8 @@
 #import "SPBundleHTMLOutputController.h"
 #endif
 #import "SPFunctions.h"
+#import "SPHelpViewerClient.h"
+#import "SPHelpViewerController.h"
 
 #import <pthread.h>
 #import <SPMySQL/SPMySQL.h>
@@ -68,10 +70,10 @@
 @interface SPCustomQuery ()
 
 - (id)_resultDataItemAtRow:(NSInteger)row columnIndex:(NSUInteger)column preserveNULLs:(BOOL)preserveNULLs asPreview:(BOOL)asPreview;
-+ (NSString *)linkToHelpTopic:(NSString *)aTopic;
 - (void)documentWillClose:(NSNotification *)notification;
 - (void)queryFavoritesHaveBeenUpdated:(NSNotification *)notification;
 - (void)historyItemsHaveBeenUpdated:(NSNotification *)notification;
+- (void)helpWindowClosedByUser:(NSNotification *)notification;
 
 @end
 
@@ -2830,221 +2832,14 @@
 
 #endif
 
-#pragma mark -
-#pragma mark MySQL Help
-
 /**
- * Set the MySQL version as X.Y for Help window title and online search
+ * Set the MySQL version as X.Y
  */
 - (void)setMySQLversion:(NSString *)theVersion
 {
-	mySQLversion = [[theVersion substringToIndex:3] retain];
-	[textView setConnection:mySQLConnection withVersion:[[[mySQLversion componentsSeparatedByString:@"."] objectAtIndex:0] integerValue]];
-}
-
-#ifndef SP_CODA
-/**
- * Return the Help window.
- */
-- (NSWindow *)helpWebViewWindow
-{
-	return helpWebViewWindow;
+	[textView setConnection:mySQLConnection withVersion:[[[[theVersion substringToIndex:3] componentsSeparatedByString:@"."] objectAtIndex:0] integerValue]];
 }
 
-/**
- * Show the data for "HELP 'searchString'".
- */
-- (void)showHelpFor:(NSString *)searchString addToHistory:(BOOL)addToHistory calledByAutoHelp:(BOOL)autoHelp
-{
-
-	// If there's no search string, show nothing if called by autohelp, and the index otherwise
-	if (![searchString length]) {
-		if (autoHelp) return;
-		searchString = SP_HELP_TOC_SEARCH_STRING;
-	}
-
-	NSString *helpString = [self getHTMLformattedMySQLHelpFor:searchString calledByAutoHelp:autoHelp];
-
-	if(autoHelp && [helpString isEqualToString:SP_HELP_NOT_AVAILABLE]) {
-		[helpWebViewWindow orderOut:nil];
-		return;
-	}
-
-	// Order out resp. init the Help window if not visible
-	if(![helpWebViewWindow isVisible])
-	{
-		// set title of the Help window
-		[helpWebViewWindow setTitle:[NSString stringWithFormat:@"%@ (%@ %@)", NSLocalizedString(@"MySQL Help", @"mysql help"), NSLocalizedString(@"version", @"version"), mySQLversion]];
-
-		// init goback/forward buttons
-		if([[helpWebView backForwardList] backListCount] < 1)
-		{
-			[helpNavigator setEnabled:NO forSegment:SP_HELP_GOBACK_BUTTON];
-			[helpNavigator setEnabled:NO forSegment:SP_HELP_GOFORWARD_BUTTON];
-		} else {
-			[helpNavigator setEnabled:[[helpWebView backForwardList] backListCount] forSegment:SP_HELP_GOBACK_BUTTON];
-			[helpNavigator setEnabled:[[helpWebView backForwardList] forwardListCount] forSegment:SP_HELP_GOFORWARD_BUTTON];
-		}
-
-		// set default to search in MySQL help
-		helpTarget = SP_HELP_SEARCH_IN_MYSQL;
-		[helpTargetSelector setSelectedSegment:SP_HELP_SEARCH_IN_MYSQL];
-		[self helpTargetValidation];
-
-		// order out Help window if Help is available
-		if(![helpString isEqualToString:SP_HELP_NOT_AVAILABLE])
-			[helpWebViewWindow orderFront:helpWebView];
-	}
-
-	// close Help window if no Help available
-	if([helpString isEqualToString:SP_HELP_NOT_AVAILABLE])
-		[helpWebViewWindow close];
-
-	if(![helpString length]) return;
-
-	// add searchString to history list
-	if(addToHistory)
-	{
-		WebHistoryItem *aWebHistoryItem = [[WebHistoryItem alloc] initWithURLString:[NSString stringWithFormat:@"applewebdata://%@", searchString] title:searchString lastVisitedTimeInterval:[[NSDate date] timeIntervalSinceDate:[NSDate distantFuture]]];
-		[[helpWebView backForwardList] addItem:aWebHistoryItem];
-		[aWebHistoryItem release];
-	}
-
-	// validate goback/forward buttons
-	[helpNavigator setEnabled:[[helpWebView backForwardList] backListCount] forSegment:SP_HELP_GOBACK_BUTTON];
-	[helpNavigator setEnabled:[[helpWebView backForwardList] forwardListCount] forSegment:SP_HELP_GOFORWARD_BUTTON];
-
-	// load HTML formatted help into the webview
-	[[helpWebView mainFrame] loadHTMLString:helpString baseURL:nil];
-}
-
-/**
- * Show the data for "HELP 'search word'" according to helpTarget
- */
-- (IBAction)showHelpForSearchString:(id)sender
-{
-	NSString *searchString = [[helpSearchField stringValue] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
-	switch(helpTarget)
-	{
-		case SP_HELP_SEARCH_IN_PAGE:
-			if(![helpWebView searchFor:searchString direction:YES caseSensitive:NO wrap:YES])
-				if([searchString length]) NSBeep();
-			break;
-		case SP_HELP_SEARCH_IN_WEB:
-			if(![searchString length])
-				break;
-			[self openMySQLonlineDocumentationWithString:searchString];
-			break;
-		case SP_HELP_SEARCH_IN_MYSQL:
-			[self showHelpFor:searchString addToHistory:YES calledByAutoHelp:NO];
-			break;
-	}
-}
-
-/**
- * Show the Help for the selected text in the webview
- */
-- (IBAction)showHelpForWebViewSelection:(id)sender
-{
-	[self showHelpFor:[[helpWebView selectedDOMRange] text] addToHistory:YES calledByAutoHelp:NO];
-}
-
-/*
- * Show MySQL's online documentation for the selected text in the webview
- */
-- (IBAction)searchInDocForWebViewSelection:(id)sender
-{
-	NSString *searchString = [[[helpWebView selectedDOMRange] text] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
-	if(![searchString length])
-	{
-		NSBeep();
-		return;
-	}
-	[self openMySQLonlineDocumentationWithString:searchString];
-}
-
-
-/**
- * Show the data for "HELP 'currentWord'"
- */
-- (IBAction)showHelpForCurrentWord:(id)sender
-{
-	NSString *searchString = [[sender string] substringWithRange:[sender getRangeForCurrentWord]];
-	[self showHelpFor:searchString addToHistory:YES calledByAutoHelp:NO];
-}
-
-/**
- * Find Next/Previous in current page
- */
-- (IBAction)helpSearchFindNextInPage:(id)sender
-{
-	if(helpTarget == SP_HELP_SEARCH_IN_PAGE)
-		if(![helpWebView searchFor:[[helpSearchField stringValue] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] direction:YES caseSensitive:NO wrap:YES])
-			NSBeep();
-}
-
-- (IBAction)helpSearchFindPreviousInPage:(id)sender
-{
-	if(helpTarget == SP_HELP_SEARCH_IN_PAGE)
-		if(![helpWebView searchFor:[[helpSearchField stringValue] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] direction:NO caseSensitive:NO wrap:YES])
-			NSBeep();
-}
-
-/**
- * Navigation for back/TOC/forward
- */
-- (IBAction)helpSegmentDispatcher:(id)sender
-{
-	switch([helpNavigator selectedSegment])
-	{
-		case SP_HELP_GOBACK_BUTTON:
-			[helpWebView goBack];
-			break;
-		case SP_HELP_SHOW_TOC_BUTTON:
-			[self showHelpFor:SP_HELP_TOC_SEARCH_STRING addToHistory:YES calledByAutoHelp:NO];
-			break;
-		case SP_HELP_GOFORWARD_BUTTON:
-			[helpWebView goForward];
-			break;
-	}
-	
-	// validate goback and goforward buttons according history
-	[helpNavigator setEnabled:[[helpWebView backForwardList] backListCount] forSegment:SP_HELP_GOBACK_BUTTON];
-	[helpNavigator setEnabled:[[helpWebView backForwardList] forwardListCount] forSegment:SP_HELP_GOFORWARD_BUTTON];
-
-}
-
-/**
- * Set helpTarget according user choice via mouse and keyboard short-cuts.
- */
-- (IBAction)helpSelectHelpTargetMySQL:(id)sender
-{
-	helpTarget = SP_HELP_SEARCH_IN_MYSQL;
-	[helpTargetSelector setSelectedSegment:SP_HELP_SEARCH_IN_MYSQL];
-	[self helpTargetValidation];
-}
-
-- (IBAction)helpSelectHelpTargetPage:(id)sender
-{
-	helpTarget = SP_HELP_SEARCH_IN_PAGE;
-	[helpTargetSelector setSelectedSegment:SP_HELP_SEARCH_IN_PAGE];
-	[self helpTargetValidation];
-}
-
-- (IBAction)helpSelectHelpTargetWeb:(id)sender
-{
-	helpTarget = SP_HELP_SEARCH_IN_WEB;
-	[helpTargetSelector setSelectedSegment:SP_HELP_SEARCH_IN_WEB];
-	[self helpTargetValidation];
-}
-
-- (IBAction)helpTargetDispatcher:(id)sender
-{
-	helpTarget = [helpTargetSelector selectedSegment];
-	[self helpTargetValidation];
-}
-#endif
-
 - (IBAction)showCompletionList:(id)sender
 {
 	NSRange insertRange = NSMakeRange([textView selectedRange].location, 0);
@@ -3068,294 +2863,22 @@
 - (void)showAutoHelpForCurrentWord:(id)sender
 {
 	NSString *searchString = [[sender string] substringWithRange:[sender getRangeForCurrentWord]];
-	[self showHelpFor:searchString addToHistory:YES calledByAutoHelp:YES];
-}
-
-/**
- * Control the help search field behaviour.
- */
-- (void)helpTargetValidation
-{
-	switch(helpTarget)
-	{
-		case SP_HELP_SEARCH_IN_PAGE:
-		case SP_HELP_SEARCH_IN_WEB:
-		[helpSearchFieldCell setSendsWholeSearchString:YES];
-		break;
-		case SP_HELP_SEARCH_IN_MYSQL:
-		[helpSearchFieldCell setSendsWholeSearchString:NO];
-		break;
-	}
-}
-
-- (void)openMySQLonlineDocumentationWithString:(NSString *)searchString
-{
-	NSString *version = nil;
-	if([[mySQLversion stringByReplacingOccurrencesOfString:@"." withString:@""] integerValue] < 42)
-		version = @"4.1";
-	else
-		version = [NSString stringWithString:mySQLversion];
-
-	[[NSWorkspace sharedWorkspace] openURL:[NSURL URLWithString:
-		[[NSString stringWithFormat:
-			SPMySQLSearchURL,
-			version,
-			NSLocalizedString(@"en", @"MySQL search language code - eg in http://search.mysql.com/search?q=select&site=refman-50&lr=lang_en"),
-			searchString]
-		stringByAddingPercentEscapesUsingEncoding:NSASCIIStringEncoding]]];
-}
-
-/**
- * Return the help string HTML formatted from executing "HELP 'searchString'".
- * If more than one help topic was found return a link list.
- */
-- (NSString *)getHTMLformattedMySQLHelpFor:(NSString *)searchString calledByAutoHelp:(BOOL)autoHelp
-{
-
-	if(![searchString length]) return @"";
-
-	// Don't escape % when being used as a wildcard, but escape it when it's being used by itself.
-	if ([searchString isEqualToString:@"%"]) searchString = @"\\%";
-
-	NSRange         aRange;
-	SPMySQLResult   *theResult = nil;
-	NSDictionary    *tableDetails;
-	NSMutableString *theHelp = [NSMutableString string];
-
-	[theHelp setString:@""];
-
-	// search via: HELP 'searchString'
-	theResult = [mySQLConnection queryString:[NSString stringWithFormat:@"HELP '%@'", [searchString stringByReplacingOccurrencesOfString:@"'" withString:@"\\'"]]];
-	if ([mySQLConnection queryErrored])
-	{
-		// if an error or HELP is not supported fall back to online search but
-		// don't open it if autoHelp is enabled
-		if(!autoHelp)
-			[self openMySQLonlineDocumentationWithString:searchString];
-
-		[helpWebViewWindow close];
-		return SP_HELP_NOT_AVAILABLE;
-	}
-
-	// nothing found?
-	if(![theResult numberOfRows]) {
-
-		// try to search via: HELP 'searchString%'
-		theResult = [mySQLConnection queryString:[NSString stringWithFormat:@"HELP '%@%%'", [searchString stringByReplacingOccurrencesOfString:@"'" withString:@"\\'"]]];
-
-		// really nothing found?
-		if(![theResult numberOfRows])
-			return [NSString stringWithFormat:@"<em style='color: gray'>%@</em>", NSLocalizedString(@"No results found.", @"Mysql Help Viewer : Search : No results")];
-	}
-
-	// Ensure rows are returned as strings to prevent data problems with older 4.1 servers
-	[theResult setReturnDataAsStrings:YES];
-
-	tableDetails = [[NSDictionary alloc] initWithDictionary:[theResult getRowAsDictionary]];
-
-	if ([tableDetails objectForKey:@"description"]) { // one single help topic found
-		if ([tableDetails objectForKey:@"name"]) {
-			[theHelp appendString:@"<h2 class='header'>"];
-			[theHelp appendString:[[[tableDetails objectForKey:@"name"] copy] autorelease]];
-			[theHelp appendString:@"</h2>"];
-
-		}
-		if ([tableDetails objectForKey:@"description"]) {
-			NSMutableString *desc = [NSMutableString string];
-			NSError *err1 = NULL;
-			NSString *aUrl;
-
-			[desc setString:[[[tableDetails objectForKey:@"description"] copy] autorelease]];
-
-			//[desc replaceOccurrencesOfString:[searchString uppercaseString] withString:[NSString stringWithFormat:@"<span class='searchstring'>%@</span>", [searchString uppercaseString]] options:NSLiteralSearch range:NSMakeRange(0,[desc length])];
-
-			// detect and generate http links
-			aRange = NSMakeRange(0,0);
-			NSInteger safeCnt = 0; // safety counter - not more than 200 loops allowed
-			while(1){
-				aRange = [desc rangeOfRegex:@"\\s((https?|ftp|file)://.*?html)" options:RKLNoOptions inRange:NSMakeRange(NSMaxRange(aRange), [desc length]-aRange.location-aRange.length) capture:1 error:&err1];
-				if(aRange.location != NSNotFound) {
-					aUrl = [desc substringWithRange:aRange];
-					[desc replaceCharactersInRange:aRange withString:[NSString stringWithFormat:@"<a href='%@'>%@</a>", aUrl, aUrl]];
-				}
-				else
-					break;
-				safeCnt++;
-				if(safeCnt > 200)
-					break;
-			}
-
-			// Detect and generate cross-links.  First, handle the old-style [HELP ...] text.
-			[desc replaceOccurrencesOfRegex:@"(\\[HELP ([^\\]]*?)\\]" withString:[SPCustomQuery linkToHelpTopic:@"$1"]];
-
-			// Handle "see [...]" and "in [...]"-style 5.x links.
-			//look-behind won't work here because of the \s+
-			[desc replaceOccurrencesOfRegex:@"(See|see|In|in|and)\\s+\\[(?:HELP\\s+)?([^\\]]*?)\\]" withString:[NSString stringWithFormat:@"$1 %@",[SPCustomQuery linkToHelpTopic:@"$2"]]];
-
-			[theHelp appendFormat:@"<pre class='description'>%@</pre>", desc];
-		}
-		// are examples available?
-		if([tableDetails objectForKey:@"example"]){
-			NSString *examples = [[[tableDetails objectForKey:@"example"] copy] autorelease];
-			if([examples length])
-				[theHelp appendFormat:@"<br><i><b>%1$@</b></i><br><pre class='example'>%2$@</pre>",NSLocalizedString(@"Example:",@"Mysql Help Viewer : Help Topic: Example section title"), examples];
-
-		}
-	} else { // list all found topics
-
-		// check if HELP 'contents' is called
-		if(![searchString isEqualToString:SP_HELP_TOC_SEARCH_STRING])
-			[theHelp appendFormat:@"<br><i>%@</i><br>", [NSString stringWithFormat:NSLocalizedString(@"Help topics for “%@”", @"MySQL Help Viewer : Results list : Page title"), searchString]];
-		else
-			[theHelp appendFormat:@"<br><b>%@:</b><br>", NSLocalizedString(@"MySQL Help – Categories", @"mysql help categories")];
-
-		// iterate through all found rows and print them as HTML ul/li list
-		[theHelp appendString:@"<ul>"];
-		[theResult setDefaultRowReturnType:SPMySQLResultRowAsArray];
-		for (NSArray *eachRow in theResult) {
-			NSString *topic = [eachRow objectAtIndex:[eachRow count]-2];
-			[theHelp appendFormat:@"<li>%@</li>",[SPCustomQuery linkToHelpTopic:topic]];
-		}
-		[theHelp appendString:@"</ul>"];
-	}
-
-	[tableDetails release];
-
-	return [NSString stringWithFormat:helpHTMLTemplate, theHelp];
-}
-
-+ (NSString *)linkToHelpTopic:(NSString *)aTopic 
-{
-	NSString *linkTitle = [NSString stringWithFormat:NSLocalizedString(@"Show MySQL help for “%@”", @"MySQL Help Viewer : Results list : Link tooltip"),aTopic];
-	return [NSString stringWithFormat:@"<a title='%2$@' href='%1$@' class='internallink'>%1$@</a>", aTopic, linkTitle];
-}
-
-#pragma mark -
-#pragma mark WebView delegate methods
-
-/**
- * Link detector: If user clicked at an http link open it in the default browser,
- * otherwise search for it in the MySQL help. Additionally handle back/forward events from
- * keyboard and context menu.
- */
-- (void)webView:(WebView *)webView decidePolicyForNavigationAction:(NSDictionary *)actionInformation request:(NSURLRequest *)request frame:(WebFrame *)frame decisionListener:(id<WebPolicyDecisionListener>)listener
-{
-	NSInteger navigationType = [[actionInformation objectForKey:WebActionNavigationTypeKey] integerValue];
-
-	if([[[request URL] scheme] isEqualToString:@"applewebdata"] && navigationType == WebNavigationTypeLinkClicked){
-		[self showHelpFor:[[[request URL] path] lastPathComponent] addToHistory:YES calledByAutoHelp:NO];
-		[listener ignore];
-	} else {
-		if (navigationType == WebNavigationTypeOther) {
-			// catch reload event
-			// if([[[actionInformation objectForKey:WebActionOriginalURLKey] absoluteString] isEqualToString:@"about:blank"])
-			// 	[listener use];
-			// else
-			[listener use];
-		} else if (navigationType == WebNavigationTypeLinkClicked) {
-			// show http in browser
-			[[NSWorkspace sharedWorkspace] openURL:[actionInformation objectForKey:WebActionOriginalURLKey]];
-			[listener ignore];
-		} else if (navigationType == WebNavigationTypeBackForward) {
-			// catch back/forward events from contextual menu
-			[self showHelpFor:[[[[actionInformation objectForKey:WebActionOriginalURLKey] absoluteString] lastPathComponent] stringByReplacingPercentEscapesUsingEncoding:NSASCIIStringEncoding] addToHistory:NO calledByAutoHelp:NO];
-			[listener ignore];
-		} else if (navigationType == WebNavigationTypeReload) {
-			// just in case
-			[listener ignore];
-		} else {
-			// Ignore WebNavigationTypeFormSubmitted, WebNavigationTypeFormResubmitted.
-			[listener ignore];
-		}
-	}
-}
-
-/**
- * Manage contextual menu in helpWebView
- * Ignore "Reload", "Open Link", "Open Link in new Window", "Download link" etc.
- */
-- (NSArray *)webView:(WebView *)sender contextMenuItemsForElement:(NSDictionary *)element defaultMenuItems:(NSArray *)defaultMenuItems
-{
-
-	NSMutableArray *webViewMenuItems = [[defaultMenuItems mutableCopy] autorelease];
-
-	if (webViewMenuItems)
-	{
-		// Remove all needless default menu items
-		NSEnumerator *itemEnumerator = [defaultMenuItems objectEnumerator];
-		NSMenuItem *menuItem = nil;
-		
-		while ((menuItem = [itemEnumerator nextObject]))
-		{
-			NSInteger tag = [menuItem tag];
-			
-			switch (tag)
-			{
-				case 2000: // WebMenuItemTagOpenLink
-				case WebMenuItemTagOpenLinkInNewWindow:
-				case WebMenuItemTagDownloadLinkToDisk:
-				case WebMenuItemTagOpenImageInNewWindow:
-				case WebMenuItemTagDownloadImageToDisk:
-				case WebMenuItemTagCopyImageToClipboard:
-				case WebMenuItemTagOpenFrameInNewWindow:
-				case WebMenuItemTagStop:
-				case WebMenuItemTagReload:
-				case WebMenuItemTagCut:
-				case WebMenuItemTagPaste:
-				case WebMenuItemTagSpellingGuess:
-				case WebMenuItemTagNoGuessesFound:
-				case WebMenuItemTagIgnoreSpelling:
-				case WebMenuItemTagLearnSpelling:
-				case WebMenuItemTagOther:
-				case WebMenuItemTagOpenWithDefaultApplication:
-				[webViewMenuItems removeObjectIdenticalTo: menuItem];
-				break;
-			}
-		}
-	}
-
-	// Add two menu items for a selection if no link is given
-	if(webViewMenuItems
-		&& [[element objectForKey:@"WebElementIsSelected"] boolValue]
-		&& ![[element objectForKey:@"WebElementLinkIsLive"] boolValue])
-	{
-
-		NSMenuItem *searchInMySQL;
-		NSMenuItem *searchInMySQLonline;
-
-		[webViewMenuItems insertObject:[NSMenuItem separatorItem] atIndex:0];
-
-		searchInMySQLonline = [[NSMenuItem alloc] initWithTitle:NSLocalizedString(@"Search in MySQL Documentation", @"Search in MySQL Documentation") action:@selector(searchInDocForWebViewSelection:) keyEquivalent:@""];
-		[searchInMySQLonline setEnabled:YES];
-		[searchInMySQLonline setTarget:self];
-		[webViewMenuItems insertObject:searchInMySQLonline atIndex:0];
-		[searchInMySQLonline release];
-
-		searchInMySQL = [[NSMenuItem alloc] initWithTitle:NSLocalizedString(@"Search in MySQL Help", @"Search in MySQL Help") action:@selector(showHelpForWebViewSelection:) keyEquivalent:@""];
-		[searchInMySQL setEnabled:YES];
-		[searchInMySQL setTarget:self];
-		[webViewMenuItems insertObject:searchInMySQL atIndex:0];
-		[searchInMySQL release];
-
-	}
-
-	return webViewMenuItems;
+	[[tableDocumentInstance helpViewerClient] showHelpFor:searchString addToHistory:YES calledByAutoHelp:YES];
 }
 
 /**
  * Detect when the help window is closed (manually) and disable autohelp to ensure it
  * isn't reopened on keypresses.
  */
-- (BOOL)windowShouldClose:(id)sender
+- (void)helpWindowClosedByUser:(NSNotification *)notification
 {
-	if (sender == helpWebViewWindow) {
-		[prefs setBool:NO forKey:SPCustomQueryUpdateAutoHelp];
-		[prefs synchronize];
-		[autohelpMenuItem setState:NSOffState];
-		[textView setAutohelp:NO];
-	}
+	if ([notification object] != [tableDocumentInstance helpViewerClient]) return;
 
-	return YES;
+	//TODO: this doesn't belong in the document context, since multiple open documents can become out of sync through this
+	[prefs setBool:NO forKey:SPCustomQueryUpdateAutoHelp];
+	[prefs synchronize];
+	[autohelpMenuItem setState:NSOffState];
+	[textView setAutohelp:NO];
 }
 
 #endif
@@ -3749,26 +3272,6 @@
 		selectionIndexToRestore = nil;
 		selectionViewportToRestore = NSZeroRect;
 
-#ifndef SP_CODA
-		// init helpHTMLTemplate
-		NSError *error;
-
-		helpHTMLTemplate = [[NSString alloc]
-							initWithContentsOfFile:[[NSBundle mainBundle] pathForResource:SPHTMLHelpTemplate ofType:@"html"]
-							encoding:NSUTF8StringEncoding
-							error:&error];
-
-		// an error occurred while reading
-		if (helpHTMLTemplate == nil) {
-			NSLog(@"%@", [NSString stringWithFormat:@"Error reading “%@.html”!<br>%@", SPHTMLHelpTemplate, [error localizedFailureReason]]);
-			NSBeep();
-		}
-
-		// init search history
-		[helpWebView setMaintainsBackForwardList:YES];
-		[[helpWebView backForwardList] setCapacity:20];
-#endif
-
 		// init tableView's data source
 		resultData = [[SPDataStorage alloc] init];
 		editedRow = -1;
@@ -4003,6 +3506,10 @@
 	                                         selector:@selector(historyItemsHaveBeenUpdated:)
 	                                             name:SPHistoryItemsHaveBeenUpdatedNotification
 	                                           object:nil];
+	[[NSNotificationCenter defaultCenter] addObserver:self
+	                                         selector:@selector(helpWindowClosedByUser:)
+	                                             name:SPUserClosedHelpViewerNotification
+	                                           object:[tableDocumentInstance helpViewerClient]];
 
 #ifndef SP_CODA
 	[prefs addObserver:self forKeyPath:SPGlobalResultTableFont options:NSKeyValueObservingOptionNew context:NULL];
@@ -4088,10 +3595,6 @@
 
 	if(fieldEditor) SPClear(fieldEditor);
 
-#ifndef SP_CODA
-	if (helpHTMLTemplate)        SPClear(helpHTMLTemplate);
-#endif
-	if (mySQLversion)            SPClear(mySQLversion);
 	if (sortField)               SPClear(sortField);
 	if (cqColumnDefinition)      SPClear(cqColumnDefinition);
 	if (selectionIndexToRestore) SPClear(selectionIndexToRestore);
diff --git a/Source/SPDatabaseDocument.h b/Source/SPDatabaseDocument.h
index 20fb34d1..ceaca039 100644
--- a/Source/SPDatabaseDocument.h
+++ b/Source/SPDatabaseDocument.h
@@ -60,6 +60,7 @@
 @class SPExtendedTableInfo;
 @class SPTableTriggers;
 @class SPTableRelations;
+@class SPHelpViewerClient;
 
 #import "SPDatabaseContentViewDelegate.h"
 #import "SPConnectionControllerDelegateProtocol.h"
@@ -92,6 +93,7 @@
 	IBOutlet id spHistoryControllerInstance;
 	IBOutlet id exportControllerInstance;
 #endif
+	IBOutlet SPHelpViewerClient *helpViewerClientInstance;
 
 	IBOutlet id statusTableAccessoryView;
 	IBOutlet id statusTableView;
@@ -325,6 +327,8 @@
 @property (readonly) SPDatabaseStructure *databaseStructureRetrieval;
 @property (readonly) int64_t instanceId;
 
+- (SPHelpViewerClient *)helpViewerClient;
+
 #ifndef SP_CODA /* method decls */
 - (BOOL)isUntitled;
 #endif
diff --git a/Source/SPDatabaseDocument.m b/Source/SPDatabaseDocument.m
index 4bdd0aad..4909282c 100644
--- a/Source/SPDatabaseDocument.m
+++ b/Source/SPDatabaseDocument.m
@@ -48,7 +48,6 @@
 #import "SPSQLParser.h"
 #import "SPTableData.h"
 #import "SPDatabaseData.h"
-#import "SPDatabaseStructure.h"
 #import "SPExtendedTableInfo.h"
 #import "SPHistoryController.h"
 #import "SPPreferenceController.h"
@@ -85,6 +84,8 @@
 #import "ICUTemplateMatcher.h"
 #import "SPFavoritesOutlineView.h"
 #import "SPSSHTunnel.h"
+#import "SPHelpViewerClient.h"
+#import "SPHelpViewerController.h"
 
 #import <SPMySQL/SPMySQL.h>
 
@@ -511,6 +512,8 @@ static int64_t SPDatabaseDocumentInstanceCounter = 0;
 	// Set the custom query editor's MySQL version
 	[customQueryInstance setMySQLversion:mySQLVersion];
 
+	[helpViewerClientInstance setConnection:mySQLConnection];
+
 #ifndef SP_CODA
 	[self updateWindowTitle:self];
 	
@@ -2661,6 +2664,11 @@ static int64_t SPDatabaseDocumentInstanceCounter = 0;
 	}
 }
 
+- (SPHelpViewerClient *)helpViewerClient
+{
+	return helpViewerClientInstance;
+}
+
 /**
  * Is current document Untitled?
  */
@@ -3602,8 +3610,8 @@ static int64_t SPDatabaseDocumentInstanceCounter = 0;
  */
 - (IBAction)showMySQLHelp:(id)sender
 {
-	[customQueryInstance showHelpFor:SP_HELP_TOC_SEARCH_STRING addToHistory:YES calledByAutoHelp:NO];
-	[[customQueryInstance helpWebViewWindow] makeKeyWindow];
+	[helpViewerClientInstance showHelpFor:SPHelpViewerSearchTOC addToHistory:YES calledByAutoHelp:NO];
+	[[helpViewerClientInstance helpWebViewWindow] makeKeyWindow];
 }
 #endif
 
diff --git a/Source/SPHelpViewerClient.h b/Source/SPHelpViewerClient.h
new file mode 100644
index 00000000..b169e99f
--- /dev/null
+++ b/Source/SPHelpViewerClient.h
@@ -0,0 +1,66 @@
+//
+//  SPHelpViewerClient.h
+//  sequel-pro
+//
+//  Created by Max Lohrmann on 25.05.18.
+//  Copyright (c) 2018 Max Lohrmann. All rights reserved.
+//  Parts relocated from existing files. Previous copyright applies.
+//
+//  Permission is hereby granted, free of charge, to any person
+//  obtaining a copy of this software and associated documentation
+//  files (the "Software"), to deal in the Software without
+//  restriction, including without limitation the rights to use,
+//  copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the
+//  Software is furnished to do so, subject to the following
+//  conditions:
+//
+//  The above copyright notice and this permission notice shall be
+//  included in all copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+//  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+//  OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+//  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+//  HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+//  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+//  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+//  OTHER DEALINGS IN THE SOFTWARE.
+//
+//  More info at <https://github.com/sequelpro/sequelpro>
+
+@class SPHelpViewerController;
+@class SPMySQLConnection;
+@class MGTemplateEngine;
+
+/**
+ * This is the client side of the Help Viewer window, i.e. this class
+ * can be instantiated from within an xib file as a custom object.
+ *
+ * It also contains the logic to look up the help in the mysql database
+ * using the mySQLConnection (which does not belong into the Help Viewer's
+ * window controller).
+ *
+ * Notifications posted:
+ *  * SPUserClosedHelpViewerNotification
+ *      When the user triggered closing the help viewer window
+ */
+@interface SPHelpViewerClient : NSObject
+{
+	SPHelpViewerController *controller;
+
+	NSString *helpHTMLTemplate;
+	SPMySQLConnection *mySQLConnection;
+
+	MGTemplateEngine *engine;
+}
+
+- (void)setConnection:(SPMySQLConnection *)theConnection;
+
+- (NSWindow *)helpWebViewWindow;
+
+- (void)showHelpFor:(NSString *)aString addToHistory:(BOOL)addToHistory calledByAutoHelp:(BOOL)autoHelp;
+
+// this is not bound in Interface Builder, but used by the SPTextView context menu
+- (IBAction)showHelpForCurrentWord:(id)sender;
+@end
diff --git a/Source/SPHelpViewerClient.m b/Source/SPHelpViewerClient.m
new file mode 100644
index 00000000..54d8633d
--- /dev/null
+++ b/Source/SPHelpViewerClient.m
@@ -0,0 +1,262 @@
+//
+//  SPHelpViewerClient.m
+//  sequel-pro
+//
+//  Created by Max Lohrmann on 25.05.18.
+//  Copyright (c) 2018 Max Lohrmann. All rights reserved.
+//  Parts relocated from existing files. Previous copyright applies.
+//
+//  Permission is hereby granted, free of charge, to any person
+//  obtaining a copy of this software and associated documentation
+//  files (the "Software"), to deal in the Software without
+//  restriction, including without limitation the rights to use,
+//  copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the
+//  Software is furnished to do so, subject to the following
+//  conditions:
+//
+//  The above copyright notice and this permission notice shall be
+//  included in all copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+//  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+//  OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+//  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+//  HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+//  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+//  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+//  OTHER DEALINGS IN THE SOFTWARE.
+//
+//  More info at <https://github.com/sequelpro/sequelpro>
+
+#import "SPHelpViewerClient.h"
+#import "SPHelpViewerController.h"
+#import <SPMySQL/SPMySQL.h>
+#import "RegexKitLite.h"
+#import "MGTemplateEngine.h"
+#import "ICUTemplateMatcher.h"
+
+@interface SPHelpViewerClient () <SPHelpViewerDataSource>
+
++ (NSString *)linkToHelpTopic:(NSString *)aTopic;
+
+- (void)helpViewerClosed:(NSNotification *)notification;
+
+@end
+
+@implementation SPHelpViewerClient
+
+- (instancetype)init
+{
+	if (self = [super init]) {
+		controller = [[SPHelpViewerController alloc] init];
+		[controller setDataSource:self];
+		[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(helpViewerClosed:) name:SPUserClosedHelpViewerNotification object:controller];
+
+		// init helpHTMLTemplate
+		NSError *error;
+
+		helpHTMLTemplate = [[NSString alloc] initWithContentsOfFile:[[NSBundle mainBundle] pathForResource:SPHTMLHelpTemplate ofType:@"html"]
+		                                                   encoding:NSUTF8StringEncoding
+		                                                      error:&error];
+
+		// Set up template engine with your chosen matcher
+		engine = [[MGTemplateEngine alloc] init];
+		[engine setMatcher:[ICUTemplateMatcher matcherWithTemplateEngine:engine]];
+
+		// an error occurred while reading
+		if (helpHTMLTemplate == nil) {
+			helpHTMLTemplate = [@"<html><body>{{body}}</body></html>" copy]; //fallback
+			NSLog(@"%@", [NSString stringWithFormat:@"Error reading “%@.html”!<br>%@", SPHTMLHelpTemplate, [error localizedFailureReason]]);
+			NSBeep();
+		}
+	}
+	return self;
+}
+
+- (void)dealloc
+{
+	[[NSNotificationCenter defaultCenter] removeObserver:self];
+	[controller setDataSource:nil]; // we are the (unretained) datasource, but the controller may outlive us (if retained by other objects)
+	[controller close]; // hide the window if it is still visible (can't update anymore without delegate anyway)
+	
+	mySQLConnection = nil;
+	SPClear(controller);
+	SPClear(helpHTMLTemplate);
+	SPClear(engine);
+	[super dealloc];
+}
+
+- (void)helpViewerClosed:(NSNotification *)notification
+{
+	//we'll just proxy that notification because outsiders can't/shouldn't access the controller
+	[[NSNotificationCenter defaultCenter] postNotificationName:SPUserClosedHelpViewerNotification object:self];
+}
+
+- (void)openOnlineHelpForTopic:(NSString *)searchString
+{
+	NSString *version = nil;
+	if(![mySQLConnection serverVersionIsGreaterThanOrEqualTo:4 minorVersion:1 releaseVersion:0])
+		version = @"4.1";
+	else
+		version = [NSString stringWithFormat:@"%u.%u",(unsigned int)[mySQLConnection serverMajorVersion], (unsigned int)[mySQLConnection serverMinorVersion]];
+
+	NSString *url = [[NSString stringWithFormat:
+		SPMySQLSearchURL,
+		version,
+		NSLocalizedString(@"en", @"MySQL search language code - eg in http://search.mysql.com/search?q=select&site=refman-50&lr=lang_en"),
+		searchString]
+		stringByAddingPercentEscapesUsingEncoding:NSASCIIStringEncoding];
+
+	if([url length]) [[NSWorkspace sharedWorkspace] openURL:[NSURL URLWithString:url]];
+}
+
+- (NSString *)HTMLHelpContentsForSearchString:(NSString *)searchString autoHelp:(BOOL)autoHelp
+{
+	if(![searchString length]) return @"";
+
+	NSMutableString *theTitle = [NSMutableString stringWithFormat:NSLocalizedString(@"Version %@", @"Mysql Help Viewer : window title : mysql server version"),[mySQLConnection serverVersionString]];
+	NSMutableString *theHelp = [NSMutableString string];
+
+	// Don't escape % when being used as a wildcard, but escape it when it's being used by itself.
+	if ([searchString isEqualToString:@"%"]) searchString = @"\\%";
+
+	// search via: HELP 'searchString'
+	SPMySQLResult *theResult = [mySQLConnection queryString:[NSString stringWithFormat:@"HELP %@", [searchString tickQuotedString]]];
+	if ([mySQLConnection queryErrored]) {
+		[theTitle setString:NSLocalizedString(@"Error", @"Mysql Help Viewer : window title : query error")];
+		NSString *errMsg = [NSString stringWithFormat:@"ERROR %lu (%@): %@", (unsigned long)[mySQLConnection lastErrorID], [mySQLConnection lastSqlstate], [mySQLConnection lastErrorMessage]];
+		[theHelp appendFormat:@"<b>%@:</b><br><p class='error'>%@</p>", NSLocalizedString(@"MySQL Help Query Failed", @"Mysql Help Viewer : title of error message"), errMsg];
+		goto generate_help;
+	}
+
+	// nothing found?
+	if(![theResult numberOfRows]) {
+		// try to search via: HELP 'searchString%'
+		theResult = [mySQLConnection queryString:[NSString stringWithFormat:@"HELP %@", [[searchString stringByAppendingString:@"%"] tickQuotedString]]];
+
+		// really nothing found?
+		if(![theResult numberOfRows]) {
+			[theTitle appendFormat:@": %@", NSLocalizedString(@"No Results", @"Mysql Help Viewer : window title : nothing found")];
+			[theHelp appendFormat:@"<em class='nothing'>%@</em>", NSLocalizedString(@"No results found.", @"Mysql Help Viewer : Search : No results")];
+			goto generate_help;
+		}
+	}
+
+	// Ensure rows are returned as strings to prevent data problems with older 4.1 servers
+	[theResult setReturnDataAsStrings:YES];
+
+	NSDictionary *tableDetails = [[NSDictionary alloc] initWithDictionary:[theResult getRowAsDictionary]];
+
+	if ([tableDetails objectForKey:@"description"]) { // one single help topic found
+		if ([tableDetails objectForKey:@"name"]) {
+			[theTitle appendFormat:@": %@", [tableDetails objectForKey:@"name"]];
+			[theHelp appendString:@"<h2 class='header'>"];
+			[theHelp appendString:[tableDetails objectForKey:@"name"]];
+			[theHelp appendString:@"</h2>"];
+		}
+		if ([tableDetails objectForKey:@"description"]) {
+			NSMutableString *desc = [NSMutableString string];
+			NSError *err1 = NULL;
+			NSString *aUrl;
+
+			[desc setString:[tableDetails objectForKey:@"description"]];
+
+			//[desc replaceOccurrencesOfString:[searchString uppercaseString] withString:[NSString stringWithFormat:@"<span class='searchstring'>%@</span>", [searchString uppercaseString]] options:NSLiteralSearch range:NSMakeRange(0,[desc length])];
+
+			// detect and generate http links
+			NSRange aRange = NSMakeRange(0,0);
+			NSInteger safeCnt = 0; // safety counter - not more than 200 loops allowed
+			while(1) {
+				aRange = [desc rangeOfRegex:@"\\s((https?|ftp|file)://.*?html)" options:RKLNoOptions inRange:NSMakeRange(NSMaxRange(aRange), [desc length]-aRange.location-aRange.length) capture:1 error:&err1];
+				if(aRange.location != NSNotFound) {
+					aUrl = [desc substringWithRange:aRange];
+					[desc replaceCharactersInRange:aRange withString:[NSString stringWithFormat:@"<a href='%@'>%@</a>", aUrl, aUrl]];
+				}
+				else {
+					break;
+				}
+				safeCnt++;
+				if(safeCnt > 200) break;
+			}
+
+			// Detect and generate cross-links.  First, handle the old-style [HELP ...] text.
+			[desc replaceOccurrencesOfRegex:@"(\\[HELP ([^\\]]*?)\\]" withString:[[self class] linkToHelpTopic:@"$1"]];
+
+			// Handle "see [...]" and "in [...]"-style 5.x links.
+			//look-behind won't work here because of the \s+
+			[desc replaceOccurrencesOfRegex:@"(See|see|In|in|and)\\s+\\[(?:HELP\\s+)?([^\\]]*?)\\]" withString:[NSString stringWithFormat:@"$1 %@",[[self class] linkToHelpTopic:@"$2"]]];
+
+			[theHelp appendFormat:@"<pre class='description'>%@</pre>", desc];
+		}
+		// are examples available?
+		if([tableDetails objectForKey:@"example"]){
+			NSString *examples = [[[tableDetails objectForKey:@"example"] copy] autorelease];
+			if([examples length]) [theHelp appendFormat:@"<br><i><b>%1$@</b></i><br><pre class='example'>%2$@</pre>",NSLocalizedString(@"Example:",@"Mysql Help Viewer : Help Topic: Example section title"), examples];
+		}
+	}
+	else { // list all found topics
+		// check if HELP 'contents' is called
+		if(![searchString isEqualToString:SPHelpViewerSearchTOC]) {
+			[theTitle appendString:@": "];
+			[theTitle appendFormat:NSLocalizedString(@"Multiple Results for “%@”", @"Mysql Help Viewer : window title : multiple topics found"), searchString];
+			[theHelp appendFormat:@"<br><i>%@</i><br>", [NSString stringWithFormat:NSLocalizedString(@"Help topics for “%@”", @"MySQL Help Viewer : Results list : Page title"), searchString]];
+		}
+		else {
+			[theTitle appendFormat:@": %@", NSLocalizedString(@"Table of Contents", @"Mysql Help Viewer : window title : TOC")];
+			[theHelp appendFormat:@"<br><b>%@:</b><br>", NSLocalizedString(@"MySQL Help – Categories", @"mysql help categories")];
+		}
+
+		// iterate through all found rows and print them as HTML ul/li list
+		[theHelp appendString:@"<ul>"];
+		[theResult setDefaultRowReturnType:SPMySQLResultRowAsArray];
+		for (NSArray *eachRow in theResult) {
+			NSString *topic = [eachRow objectAtIndex:[eachRow count]-2];
+			[theHelp appendFormat:@"<li>%@</li>",[[self class] linkToHelpTopic:topic]];
+		}
+		[theHelp appendString:@"</ul>"];
+	}
+
+	[tableDetails release];
+
+generate_help:
+	return [engine processTemplate:helpHTMLTemplate withVariables:@{
+		@"title": theTitle,
+		@"body": theHelp,
+	}];
+}
+
++ (NSString *)linkToHelpTopic:(NSString *)aTopic
+{
+	NSString *linkTitle = [NSString stringWithFormat:NSLocalizedString(@"Show MySQL help for “%@”", @"MySQL Help Viewer : Results list : Link tooltip"),aTopic];
+	return [NSString stringWithFormat:@"<a title='%2$@' href='%1$@' class='internallink'>%1$@</a>", aTopic, linkTitle];
+}
+
+- (void)setConnection:(SPMySQLConnection *)theConnection
+{
+	mySQLConnection = theConnection;
+}
+
+/**
+ * Return the Help window.
+ */
+- (NSWindow *)helpWebViewWindow
+{
+	return [controller window];
+}
+
+- (void)showHelpFor:(NSString *)aString addToHistory:(BOOL)addToHistory calledByAutoHelp:(BOOL)autoHelp
+{
+	[controller showHelpFor:aString addToHistory:addToHistory calledByAutoHelp:autoHelp];
+}
+
+/**
+ * Show the data for "HELP 'currentWord'"
+ */
+- (IBAction)showHelpForCurrentWord:(id)sender
+{
+	NSString *searchString = [[sender string] substringWithRange:[sender getRangeForCurrentWord]];
+	[controller showHelpFor:searchString addToHistory:YES calledByAutoHelp:NO];
+}
+
+@end
diff --git a/Source/SPHelpViewerController.h b/Source/SPHelpViewerController.h
new file mode 100644
index 00000000..c4de0d54
--- /dev/null
+++ b/Source/SPHelpViewerController.h
@@ -0,0 +1,99 @@
+//
+//  SPHelpViewerController.h
+//  sequel-pro
+//
+//  Created by Max Lohrmann on 21.05.18.
+//  Copyright (c) 2018 Max Lohrmann. All rights reserved.
+//  Parts relocated from existing files. Previous copyright applies.
+//
+//  Permission is hereby granted, free of charge, to any person
+//  obtaining a copy of this software and associated documentation
+//  files (the "Software"), to deal in the Software without
+//  restriction, including without limitation the rights to use,
+//  copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the
+//  Software is furnished to do so, subject to the following
+//  conditions:
+//
+//  The above copyright notice and this permission notice shall be
+//  included in all copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+//  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+//  OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+//  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+//  HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+//  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+//  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+//  OTHER DEALINGS IN THE SOFTWARE.
+//
+//  More info at <https://github.com/sequelpro/sequelpro>
+
+@class WebView;
+
+//private
+typedef NS_ENUM(NSUInteger, HelpTarget) {
+	HelpTargetMySQL = 0,
+	HelpTargetPage = 1,
+	HelpTargetWeb = 2,
+};
+
+NSString * const SPHelpViewerSearchTOC;
+
+/**
+ * This notification is posted by the SPHelpViewerController when the user
+ * triggered closing the help viewer window (or by -performClose:).
+ * The window is not guaranteed to be off screen already, when the notification is sent.
+ *
+ * It will NOT be sent when the window was closed or hidden by code (including app termination).
+ */
+NSString * const SPUserClosedHelpViewerNotification;
+
+@protocol SPHelpViewerDataSource <NSObject>
+
+@required
+/**
+ * When called with a search string this method should open the user's default browser
+ * with an URL to the MySQL online manual for the page that explains the search string.
+ */
+- (void)openOnlineHelpForTopic:(NSString *)searchString;
+
+/**
+ * This method is called by the SPHelpViewerController when it wants to receive the HTML
+ * page to display in response to a search string.
+ *
+ * The implementation has to handle the magic search string SPHelpViewerSearchTOC to
+ * return a table of contents document.
+ */
+- (NSString *)HTMLHelpContentsForSearchString:(NSString *)searchString autoHelp:(BOOL)autoHelp;
+
+@end
+
+/**
+ * This is the window controller class for the MySQL Help Viewer panel.
+ *
+ * See SPHelpViewerClient for the class that provides data for this controller and which
+ * can be instantiated from within an XIB.
+ *
+ * - Do NOT instantiate this class from within an XIB.
+ * - None of the methods in this class are thread-safe - always use the UI thread!
+ */
+@interface SPHelpViewerController : NSWindowController
+{
+	IBOutlet WebView *helpWebView;
+
+	IBOutlet NSSearchField *helpSearchField;
+	IBOutlet NSSearchFieldCell *helpSearchFieldCell;
+	IBOutlet NSSegmentedControl *helpNavigator;
+	IBOutlet NSSegmentedControl *helpTargetSelector;
+
+	HelpTarget helpTarget;
+
+	id<SPHelpViewerDataSource> dataSource;
+}
+
+@property (assign, nonatomic) id <SPHelpViewerDataSource> dataSource;
+
+- (void)showHelpFor:(NSString *)aString addToHistory:(BOOL)addToHistory calledByAutoHelp:(BOOL)autoHelp;
+
+@end
diff --git a/Source/SPHelpViewerController.m b/Source/SPHelpViewerController.m
new file mode 100644
index 00000000..a2c13000
--- /dev/null
+++ b/Source/SPHelpViewerController.m
@@ -0,0 +1,415 @@
+//
+//  SPHelpViewerController.m
+//  sequel-pro
+//
+//  Created by Max Lohrmann on 21.05.18.
+//  Copyright (c) 2018 Max Lohrmann. All rights reserved.
+//  Parts relocated from existing files. Previous copyright applies.
+//
+//  Permission is hereby granted, free of charge, to any person
+//  obtaining a copy of this software and associated documentation
+//  files (the "Software"), to deal in the Software without
+//  restriction, including without limitation the rights to use,
+//  copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the
+//  Software is furnished to do so, subject to the following
+//  conditions:
+//
+//  The above copyright notice and this permission notice shall be
+//  included in all copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+//  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+//  OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+//  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+//  HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+//  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+//  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+//  OTHER DEALINGS IN THE SOFTWARE.
+//
+//  More info at <https://github.com/sequelpro/sequelpro>
+
+#import "SPHelpViewerController.h"
+
+#import <WebKit/WebKit.h>
+
+NSString * const SPHelpViewerSearchTOC = @"contents";
+
+NSString * const SPUserClosedHelpViewerNotification = @"SPUserClosedHelpViewer";
+
+typedef NS_ENUM(NSInteger, HelpNavButton) {
+	HelpNavButtonGoBack = 0,
+	HelpNavButtonShowTOC = 1,
+	HelpNavButtonGoForward = 2,
+};
+
+static void *HelpViewerControllerKVOContext = &HelpViewerControllerKVOContext;
+
+@interface SPHelpViewerController () <WebPolicyDelegate, WebUIDelegate, NSWindowDelegate>
+- (IBAction)showHelpForSearchString:(id)sender;
+- (IBAction)helpSegmentDispatcher:(id)sender;
+- (IBAction)helpSearchFindNextInPage:(id)sender;
+- (IBAction)helpSearchFindPreviousInPage:(id)sender;
+- (IBAction)helpTargetDispatcher:(id)sender;
+- (IBAction)helpSelectHelpTargetMySQL:(id)sender;
+- (IBAction)helpSelectHelpTargetPage:(id)sender;
+- (IBAction)helpSelectHelpTargetWeb:(id)sender;
+
+- (IBAction)showHelpForWebViewSelection:(id)sender;
+- (IBAction)searchInDocForWebViewSelection:(id)sender;
+- (void)helpTargetValidation;
+- (void)updateWindowTitle;
+@end
+
+#pragma mark -
+
+@implementation SPHelpViewerController
+
+@synthesize dataSource = dataSource;
+
+- (instancetype)init
+{
+	if ((self = [super initWithWindowNibName:@"HelpViewer"])) {
+		//force window to be loaded for simplicity
+		[self window];
+	}
+	return self;
+}
+
+- (void)dealloc
+{
+	[helpWebView removeObserver:self forKeyPath:@"mainFrameTitle"]; //TODO: update to ...context: variant after 10.6
+	[super dealloc];
+}
+
+- (void)windowDidLoad
+{
+	// init search history
+	[helpWebView setMaintainsBackForwardList:YES];
+	[[helpWebView backForwardList] setCapacity:20];
+
+	[self updateWindowTitle];
+
+	[helpWebView addObserver:self forKeyPath:@"mainFrameTitle" options:0 context:HelpViewerControllerKVOContext];
+}
+
+- (void)observeValueForKeyPath:(nullable NSString *)keyPath ofObject:(nullable id)object change:(nullable NSDictionary<NSKeyValueChangeKey, id> *)change context:(nullable void *)context
+{
+	if(context == HelpViewerControllerKVOContext) {
+		if([@"mainFrameTitle" isEqualToString:keyPath] && object == helpWebView) {
+			[self updateWindowTitle];
+		}
+	}
+	else {
+		[super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
+	}
+}
+
+- (void)updateWindowTitle
+{
+	NSString *title = NSLocalizedString(@"MySQL Help", @"mysql help");
+
+	NSString *webTitle = [helpWebView mainFrameTitle];
+	if([webTitle length]) title = [title stringByAppendingFormat:@" (%@)", webTitle];
+
+	[[self window] setTitle:title];
+}
+
+#pragma mark -
+#pragma mark MySQL Help
+
+/**
+ * Show the data for "HELP 'searchString'".
+ */
+- (void)showHelpFor:(NSString *)searchString addToHistory:(BOOL)addToHistory calledByAutoHelp:(BOOL)autoHelp
+{
+	// If there's no search string, ignore if called by autohelp, show the index otherwise
+	if (![searchString length]) {
+		if (autoHelp) return;
+		searchString = SPHelpViewerSearchTOC;
+	}
+
+	NSString *helpString = [dataSource HTMLHelpContentsForSearchString:searchString autoHelp:autoHelp];
+
+	// init the Help window if not visible
+	if(![[self window] isVisible]) {
+		// init goback/forward buttons
+		if([[helpWebView backForwardList] backListCount] < 1) {
+			[helpNavigator setEnabled:NO forSegment:HelpNavButtonGoBack];
+			[helpNavigator setEnabled:NO forSegment:HelpNavButtonGoForward];
+		}
+		else {
+			[helpNavigator setEnabled:([[helpWebView backForwardList] backListCount] != 0) forSegment:HelpNavButtonGoBack];
+			[helpNavigator setEnabled:([[helpWebView backForwardList] forwardListCount] != 0) forSegment:HelpNavButtonGoForward];
+		}
+
+		// set default to search in MySQL help
+		helpTarget = HelpTargetMySQL;
+		[helpTargetSelector setSelectedSegment:HelpTargetMySQL];
+		[self helpTargetValidation];
+
+		// show Help window
+		[[self window] orderFront:helpWebView];
+	}
+
+	if(![helpString length]) return;
+
+	// add searchString to history list
+	if(addToHistory) {
+		WebHistoryItem *aWebHistoryItem = [[WebHistoryItem alloc] initWithURLString:[NSString stringWithFormat:@"applewebdata://%@", searchString] title:searchString lastVisitedTimeInterval:[[NSDate date] timeIntervalSinceDate:[NSDate distantFuture]]];
+		[[helpWebView backForwardList] addItem:aWebHistoryItem];
+		[aWebHistoryItem release];
+	}
+
+	// validate goback/forward buttons
+	[helpNavigator setEnabled:([[helpWebView backForwardList] backListCount] != 0) forSegment:HelpNavButtonGoBack];
+	[helpNavigator setEnabled:([[helpWebView backForwardList] forwardListCount] != 0) forSegment:HelpNavButtonGoForward];
+
+	// load HTML formatted help into the webview
+	[[helpWebView mainFrame] loadHTMLString:helpString baseURL:nil];
+}
+
+/**
+ * Show the data for "HELP 'search word'" according to helpTarget
+ */
+- (IBAction)showHelpForSearchString:(id)sender
+{
+	NSString *searchString = [[helpSearchField stringValue] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+	switch(helpTarget) {
+		case HelpTargetPage:
+			if(![helpWebView searchFor:searchString direction:YES caseSensitive:NO wrap:YES]) {
+				if([searchString length]) NSBeep();
+			}
+			break;
+		case HelpTargetWeb:
+			if(![searchString length]) break;
+			[dataSource openOnlineHelpForTopic:searchString];
+			break;
+		case HelpTargetMySQL:
+			[self showHelpFor:searchString addToHistory:YES calledByAutoHelp:NO];
+			break;
+	}
+}
+
+/**
+ * Show the Help for the selected text in the webview
+ */
+- (IBAction)showHelpForWebViewSelection:(id)sender
+{
+	[self showHelpFor:[[helpWebView selectedDOMRange] text] addToHistory:YES calledByAutoHelp:NO];
+}
+
+/**
+ * Show MySQL's online documentation for the selected text in the webview
+ */
+- (IBAction)searchInDocForWebViewSelection:(id)sender
+{
+	NSString *searchString = [[[helpWebView selectedDOMRange] text] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+	if(![searchString length]) {
+		NSBeep();
+		return;
+	}
+	[dataSource openOnlineHelpForTopic:searchString];
+}
+
+/**
+ * Find Next/Previous in current page
+ */
+- (IBAction)helpSearchFindNextInPage:(id)sender
+{
+	if(helpTarget == HelpTargetPage) {
+		if(![helpWebView searchFor:[[helpSearchField stringValue] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] direction:YES caseSensitive:NO wrap:YES]) NSBeep();
+	}
+}
+
+- (IBAction)helpSearchFindPreviousInPage:(id)sender
+{
+	if(helpTarget == HelpTargetPage) {
+		if(![helpWebView searchFor:[[helpSearchField stringValue] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] direction:NO caseSensitive:NO wrap:YES]) NSBeep();
+	}
+}
+
+/**
+ * Navigation for back/TOC/forward
+ */
+- (IBAction)helpSegmentDispatcher:(id)sender
+{
+	switch((HelpNavButton)[helpNavigator selectedSegment]) {
+		case HelpNavButtonGoBack:
+			[helpWebView goBack];
+			break;
+		case HelpNavButtonShowTOC:
+			[self showHelpFor:SPHelpViewerSearchTOC addToHistory:YES calledByAutoHelp:NO];
+			break;
+		case HelpNavButtonGoForward:
+			[helpWebView goForward];
+			break;
+	}
+
+	// validate goback and goforward buttons according history
+	[helpNavigator setEnabled:([[helpWebView backForwardList] backListCount] != 0) forSegment:HelpNavButtonGoBack];
+	[helpNavigator setEnabled:([[helpWebView backForwardList] forwardListCount] != 0) forSegment:HelpNavButtonGoForward];
+}
+
+/**
+ * Set helpTarget according user choice via mouse and keyboard short-cuts.
+ */
+- (IBAction)helpSelectHelpTargetMySQL:(id)sender
+{
+	helpTarget = HelpTargetMySQL;
+	[helpTargetSelector setSelectedSegment:HelpTargetMySQL];
+	[self helpTargetValidation];
+}
+
+- (IBAction)helpSelectHelpTargetPage:(id)sender
+{
+	helpTarget = HelpTargetPage;
+	[helpTargetSelector setSelectedSegment:HelpTargetPage];
+	[self helpTargetValidation];
+}
+
+- (IBAction)helpSelectHelpTargetWeb:(id)sender
+{
+	helpTarget = HelpTargetWeb;
+	[helpTargetSelector setSelectedSegment:HelpTargetWeb];
+	[self helpTargetValidation];
+}
+
+- (IBAction)helpTargetDispatcher:(id)sender
+{
+	helpTarget = (HelpTarget)[helpTargetSelector selectedSegment];
+	[self helpTargetValidation];
+}
+
+/**
+ * Control the help search field behaviour.
+ */
+- (void)helpTargetValidation
+{
+	switch(helpTarget) {
+		case HelpTargetPage:
+		case HelpTargetWeb:
+			[helpSearchFieldCell setSendsWholeSearchString:YES];
+			break;
+		case HelpTargetMySQL:
+			[helpSearchFieldCell setSendsWholeSearchString:NO];
+			break;
+	}
+}
+
+- (BOOL)windowShouldClose:(NSWindow *)sender
+{
+	// -windowShouldClose: is the only method that will ONLY be invoked when the user closes the window (or by -performClose:)
+	[[NSNotificationCenter defaultCenter] postNotificationName:SPUserClosedHelpViewerNotification object:self];
+	return YES;
+}
+
+#pragma mark -
+#pragma mark WebView delegate methods
+
+/**
+ * Link detector: If user clicked at an http link open it in the default browser,
+ * otherwise search for it in the MySQL help. Additionally handle back/forward events from
+ * keyboard and context menu.
+ */
+- (void)webView:(WebView *)webView decidePolicyForNavigationAction:(NSDictionary *)actionInformation request:(NSURLRequest *)request frame:(WebFrame *)frame decisionListener:(id<WebPolicyDecisionListener>)listener
+{
+	NSInteger navigationType = [[actionInformation objectForKey:WebActionNavigationTypeKey] integerValue];
+
+	if([[[request URL] scheme] isEqualToString:@"applewebdata"] && navigationType == WebNavigationTypeLinkClicked) {
+		[self showHelpFor:[[[request URL] path] lastPathComponent] addToHistory:YES calledByAutoHelp:NO];
+		[listener ignore];
+	}
+	else {
+		if (navigationType == WebNavigationTypeOther) {
+			// catch reload event
+			// if([[[actionInformation objectForKey:WebActionOriginalURLKey] absoluteString] isEqualToString:@"about:blank"])
+			// 	[listener use];
+			// else
+			[listener use];
+		}
+		else if (navigationType == WebNavigationTypeLinkClicked) {
+			// show http in browser
+			[[NSWorkspace sharedWorkspace] openURL:[actionInformation objectForKey:WebActionOriginalURLKey]];
+			[listener ignore];
+		}
+		else if (navigationType == WebNavigationTypeBackForward) {
+			// catch back/forward events from contextual menu
+			[self showHelpFor:[[[[actionInformation objectForKey:WebActionOriginalURLKey] absoluteString] lastPathComponent] stringByReplacingPercentEscapesUsingEncoding:NSASCIIStringEncoding] addToHistory:NO calledByAutoHelp:NO];
+			[listener ignore];
+		}
+		else {
+			// Ignore WebNavigationTypeFormSubmitted, WebNavigationTypeFormResubmitted, WebNavigationTypeReload.
+			[listener ignore];
+		}
+	}
+}
+
+/**
+ * Manage contextual menu in helpWebView
+ * Ignore "Reload", "Open Link", "Open Link in new Window", "Download link" etc.
+ */
+- (NSArray *)webView:(WebView *)sender contextMenuItemsForElement:(NSDictionary *)element defaultMenuItems:(NSArray *)defaultMenuItems
+{
+	NSMutableArray *webViewMenuItems = [[defaultMenuItems mutableCopy] autorelease];
+
+	if (webViewMenuItems) {
+		// Remove all needless default menu items
+		NSEnumerator *itemEnumerator = [defaultMenuItems objectEnumerator];
+		NSMenuItem *menuItem = nil;
+
+		while ((menuItem = [itemEnumerator nextObject])) {
+			NSInteger tag = [menuItem tag];
+
+			switch (tag) {
+				case 2000: // WebMenuItemTagOpenLink
+				case WebMenuItemTagOpenLinkInNewWindow:
+				case WebMenuItemTagDownloadLinkToDisk:
+				case WebMenuItemTagOpenImageInNewWindow:
+				case WebMenuItemTagDownloadImageToDisk:
+				case WebMenuItemTagCopyImageToClipboard:
+				case WebMenuItemTagOpenFrameInNewWindow:
+				case WebMenuItemTagStop:
+				case WebMenuItemTagReload:
+				case WebMenuItemTagCut:
+				case WebMenuItemTagPaste:
+				case WebMenuItemTagSpellingGuess:
+				case WebMenuItemTagNoGuessesFound:
+				case WebMenuItemTagIgnoreSpelling:
+				case WebMenuItemTagLearnSpelling:
+				case WebMenuItemTagOther:
+				case WebMenuItemTagOpenWithDefaultApplication:
+					[webViewMenuItems removeObjectIdenticalTo: menuItem];
+					break;
+			}
+		}
+	}
+
+	// Add two menu items for a selection if no link is given
+	if(webViewMenuItems
+	    && [[element objectForKey:@"WebElementIsSelected"] boolValue]
+	    && ![[element objectForKey:@"WebElementLinkIsLive"] boolValue])
+	{
+
+		NSMenuItem *searchInMySQL;
+		NSMenuItem *searchInMySQLonline;
+
+		[webViewMenuItems insertObject:[NSMenuItem separatorItem] atIndex:0];
+
+		searchInMySQLonline = [[NSMenuItem alloc] initWithTitle:NSLocalizedString(@"Search in MySQL Documentation", @"Search in MySQL Documentation") action:@selector(searchInDocForWebViewSelection:) keyEquivalent:@""];
+		[searchInMySQLonline setEnabled:YES];
+		[searchInMySQLonline setTarget:self];
+		[webViewMenuItems insertObject:searchInMySQLonline atIndex:0];
+		[searchInMySQLonline release];
+
+		searchInMySQL = [[NSMenuItem alloc] initWithTitle:NSLocalizedString(@"Search in MySQL Help", @"Search in MySQL Help") action:@selector(showHelpForWebViewSelection:) keyEquivalent:@""];
+		[searchInMySQL setEnabled:YES];
+		[searchInMySQL setTarget:self];
+		[webViewMenuItems insertObject:searchInMySQL atIndex:0];
+		[searchInMySQL release];
+	}
+
+	return webViewMenuItems;
+}
+
+@end
diff --git a/Source/SPTextView.m b/Source/SPTextView.m
index de1ddc04..6b98217c 100644
--- a/Source/SPTextView.m
+++ b/Source/SPTextView.m
@@ -50,6 +50,7 @@
 #import "SPCopyTable.h"
 #import "SPEditorTokens.h"
 #import "SPSyntaxParser.h"
+#import "SPHelpViewerClient.h"
 
 #import <SPMySQL/SPMySQL.h>
 
@@ -1107,7 +1108,7 @@ retry:
  */
 - (IBAction) showMySQLHelpForCurrentWord:(id)sender
 {
-	[customQueryInstance showHelpForCurrentWord:self];
+	[[tableDocumentInstance helpViewerClient] showHelpForCurrentWord:self];
 }
 #endif