Various export enhancements and fixes, including:

- A new SPExportFile class, providing an abstract interface to the handling and creation of export files.
- Enables the centralisation of all file/file handle creation logic as well as better support for handling situations where files fail to be created, including files that already exist at the export location.
- New SPExportFileHandleStatus constants to support the reporting of file handle creation.
- Update SPExporter to use the new file class instead of directly using an instance of SPFileHandle.
- Add the necessary logic to deal with files that already exist on disk, by providing the user with 3 options: cancel the export, ignore the files in question or overwrite them. We might want to enhance this to make new files sequential in name to prevent overwriting. Fixes issue #742.
- New SPExportFileUtilities category, which centralises all the logic relating to writing export type headers as well as dealing with problems occurred during file/file handle creation.
- Improve feedback given on the export progress sheet during export initialisation.
- Tidy up and improve comments.

1 files changed, 212 insertions, 0 deletions

diff --git a/Source/SPExportFileUtilities.m b/Source/SPExportFileUtilities.m
new file mode 100644
index 00000000..4cb39455
--- /dev/null
+++ b/Source/SPExportFileUtilities.m
@@ -0,0 +1,212 @@
+//
+//  $Id$
+//
+//  SPExportFileUtilities.m
+//  sequel-pro
+//
+//  Created by Stuart Connolly (stuconnolly.com) on July 30, 2010
+//  Copyright (c) 2010 Stuart Connolly. All rights reserved.
+//
+//  This program is free software; you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation; either version 2 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+//  More info at <http://code.google.com/p/sequel-pro/>
+
+#import "SPExportFileUtilities.h"
+#import "SPExporter.h"
+#import "SPAlertSheets.h"
+
+@implementation SPExportController (SPExportFileUtilities)
+
+/**
+ * Writes the CSV file header to the supplied export file.
+ *
+ * @param file The export file to write the header to.
+ */
+- (void)writeCSVHeaderToExportFile:(SPExportFile *)file
+{
+	NSMutableString *lineEnding = [NSMutableString stringWithString:[exportCSVLinesTerminatedField stringValue]];
+	
+	// Escape tabs, line endings and carriage returns
+	[lineEnding replaceOccurrencesOfString:@"\\t" withString:@"\t"
+								   options:NSLiteralSearch
+									 range:NSMakeRange(0, [lineEnding length])];
+	
+	
+	[lineEnding replaceOccurrencesOfString:@"\\n" withString:@"\n"
+								   options:NSLiteralSearch
+									 range:NSMakeRange(0, [lineEnding length])];
+	
+	[lineEnding replaceOccurrencesOfString:@"\\r" withString:@"\r"
+								   options:NSLiteralSearch
+									 range:NSMakeRange(0, [lineEnding length])];
+	
+	// Write the file header and the first table name
+	[file writeData:[[NSMutableString stringWithFormat:@"%@: %@   %@: %@    %@: %@%@%@%@ %@%@%@",
+					  NSLocalizedString(@"Host", @"csv export host heading"),
+					  [tableDocumentInstance host], 
+					  NSLocalizedString(@"Database", @"csv export database heading"),
+					  [tableDocumentInstance database], 
+					  NSLocalizedString(@"Generation Time", @"csv export generation time heading"),
+					  [NSDate date], 
+					  lineEnding, 
+					  lineEnding,
+					  NSLocalizedString(@"Table", @"csv export table heading"),
+					  [[tables objectAtIndex:0] objectAtIndex:0],
+					  lineEnding, 
+					  lineEnding] dataUsingEncoding:[connection encoding]]];
+}
+
+/**
+ * Writes the XML file header to the supplied export file.
+ *
+ * @param file The export file to write the header to.
+ */
+- (void)writeXMLHeaderToExportFile:(SPExportFile *)file
+{
+	NSMutableString *header = [NSMutableString string];
+	
+	[header setString:@"<?xml version=\"1.0\"?>\n\n"];
+	[header appendString:@"<!--\n-\n"];
+	[header appendString:@"- Sequel Pro XML dump\n"];
+	[header appendString:[NSString stringWithFormat:@"- Version %@\n-\n", [[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleVersion"]]];
+	[header appendString:[NSString stringWithFormat:@"- %@\n- %@\n-\n", SPLOCALIZEDURL_HOMEPAGE, SPDevURL]];
+	[header appendString:[NSString stringWithFormat:@"- Host: %@ (MySQL %@)\n", [tableDocumentInstance host], [tableDocumentInstance mySQLVersion]]];
+	[header appendString:[NSString stringWithFormat:@"- Database: %@\n", [tableDocumentInstance database]]];
+	[header appendString:[NSString stringWithFormat:@"- Generation Time: %@\n", [NSDate date]]];
+	[header appendString:@"-\n-->\n\n"];
+	
+	if (exportSource == SPTableExport) {
+		[header appendString:[NSString stringWithFormat:@"<%@>\n\n", [[tableDocumentInstance database] HTMLEscapeString]]];
+	}
+	
+	[file writeData:[header dataUsingEncoding:NSUTF8StringEncoding]];	
+}
+
+/**
+ * Indicates that one or more errors occurred while attempting to create the export file handles. Asks the 
+ * user how to proceed.
+ *
+ * @param files An array of export files (SPExportFile) that failed to be created. 
+ */
+- (void)errorCreatingExportFileHandles:(NSArray *)files
+{
+	// Get the number of files that already exists as well as couldn't be created because of other reasons
+	NSUInteger i = 0;
+	
+	for (SPExportFile *file in files) 
+	{
+		SPExportFileHandleStatus status = [file exportFileHandleStatus];
+		
+		if (status == SPExportFileHandleExists) {
+			i++;
+		}
+		// For file handles that we failed to create for some unknown reason, ignore them and remove any 
+		// exporters that are associated with them.
+		else if (status == SPExportFileHandleFailed) {
+			
+			for (SPExporter *exporter in exporters)
+			{
+				if ([[exporter exportOutputFile] isEqualTo:file]) {
+					[exporters removeObject:exporter];
+				}
+			}
+		}
+	}
+	
+		
+	if (i > 0) {
+		
+		NSAlert *alert = [NSAlert alertWithMessageText:NSLocalizedString(@"Error creating export files", @"export file handle creation error message") 
+										 defaultButton:NSLocalizedString(@"Ignore", @"ignore button") 
+									   alternateButton:NSLocalizedString(@"Overwrite", @"overwrite button")
+										   otherButton:NSLocalizedString(@"Cancel", @"cancel button")
+							 informativeTextWithFormat:NSLocalizedString(@"One or more errors occurred while attempting to create the export files. Those that failed to be created for unknown reasons will be ignored.\n\nHow would you like to proceed with the files that already exist at the location you have chosen to export to?", @"export file handle creation error informative message")];
+		
+		[alert setAlertStyle:NSCriticalAlertStyle];
+				
+		// Close the progress sheet
+		[NSApp endSheet:exportProgressWindow returnCode:0];
+		[exportProgressWindow orderOut:self];
+		
+		[alert beginSheetModalForWindow:[tableDocumentInstance parentWindow] modalDelegate:self didEndSelector:@selector(alertDidEnd:returnCode:contextInfo:) contextInfo:files];
+	}
+}
+
+/**
+ * NSAlert didEnd method.
+ */
+- (void)alertDidEnd:(NSAlert *)alert returnCode:(NSInteger)returnCode contextInfo:(void *)contextInfo
+{
+	NSArray *files = (NSArray *)contextInfo;
+	
+	// Ignore the files that exist and remove the associated exporters
+	if (returnCode == NSAlertDefaultReturn) {
+		
+		for (SPExportFile *file in files)
+		{
+			for (SPExporter *exporter in exporters)
+			{
+				if ([[exporter exportOutputFile] isEqualTo:file]) {
+					[exporters removeObject:exporter]; 
+				}
+			}
+		}
+		
+		[files release];
+		
+		// If we're now left with no exporters, cancel the export operation
+		if ([exporters count] == 0) {
+			[exportFiles removeAllObjects];
+		}
+		else {
+			// Start the export after a short delay to give this sheet a chance to close
+			[self performSelector:@selector(startExport) withObject:nil afterDelay:0.1];
+		}
+	}
+	// Overwrite the files and continue
+	else if (returnCode == NSAlertAlternateReturn) {
+				
+		for (SPExportFile *file in files)
+		{
+			if ([file exportFileHandleStatus] == SPExportFileHandleExists) {
+				
+				[file createExportFileHandle:YES];
+			}
+		}
+		
+		[files release];
+		
+		// Start the export after a short delay to give this sheet a chance to close
+		[self performSelector:@selector(startExport) withObject:nil afterDelay:0.1];
+		
+	}
+	// Cancel the entire export operation
+	else if (returnCode == NSAlertOtherReturn) {
+		
+		// Loop the cached export files and remove those we've already created
+		for (SPExportFile *file in exportFiles)
+		{
+			[file delete];
+		}
+		
+		[files release];
+		
+		// Finally get rid of all the exporters and files
+		[exportFiles removeAllObjects];
+		[exporters removeAllObjects];
+	}
+}
+
+@end