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, 8 insertions, 0 deletions

diff --git a/Source/SPConstants.h b/Source/SPConstants.h
index 69efe326..89f35361 100644
--- a/Source/SPConstants.h
+++ b/Source/SPConstants.h
@@ -183,6 +183,14 @@ typedef enum
 	SPBzip2Compression = 2
 } SPFileCompressionFormat;
 
+// Export file handle creation 
+typedef enum
+{
+	SPExportFileHandleCreated = 0,
+	SPExportFileHandleFailed  = 1,
+	SPExportFileHandleExists  = 2
+} SPExportFileHandleStatus;
+
 // Predefined localisable URLs
 #define SPLOCALIZEDURL_HOMEPAGE            NSLocalizedString(@"http://www.sequelpro.com/", @"Localized home page - do not localize if no translated webpage is available")
 #define SPLOCALIZEDURL_FAQ                 NSLocalizedString(@"http://www.sequelpro.com/docs/Frequently_Asked_Questions", @"Localized help page for Frequently Asked Questions - do not localize if no translated webpage is available")