Drop e-mail from mail.app into NSWindow object - objective-c

Question

I have an cocoa app where I would like to accept e-mails from mail.app dragged into the main window of the app. I have in my applicationDidFinishLaunching:
[_window registerForDraggedTypes:
[NSArray arrayWithObjects:
NSFilenamesPboardType,
(NSString *)kPasteboardTypeFileURLPromise, nil]]; //kUTTypeData
[_window setDelegate:(id) self];
This works fine, I can receive a document, in my performDragOperation: using
NSArray * files = [sender namesOfPromisedFilesDroppedAtDestination:url];
However, this only lets me drag the emails one-by-one. If I mark several emails, everything seems OK until I drop, then nothing happens. The performDragOperation is not even called.
I have tried to add kUTTypeData to the registerForDraggedTypes..., and then I get the performDragOperation... called, but then I cannot use the namesOfPromisedFilesDroppedAtDestination:url as it returns a nil pointer.
When I had the kUTTypeData included in the register... I included this in the performDragOperation to see what types in drag:
pboard = [sender draggingPasteboard];
NSLog(#"perform drag entered, %#", [pboard types]);
With the following result:
2013-07-25 15:09:50.771 BO2ICAL[1672:303] perform drag entered, (
"dyn.ah62d4rv4gu8y4zvanr41a3pwfz30n25wqz4ca5pfsr30c35feb4he2pssrxgn6vasbu1g7dfqm10c6xeeb4hw6df",
"MV Super-secret message transfer pasteboard type",
"dyn.ah62d4rv4gu8zg7puqz3c465fqr3gn7bakf41k55rqf4g86vasbu1g7dfqm10c6xeeb4hw6df",
"Super-secret Automator pasteboard type"
)
While the list for single e-mails are:
2013-07-25 15:14:30.096 BO2ICAL[1672:303] perform drag entered, (
"dyn.ah62d4rv4gu8y4zvanr41a3pwfz30n25wqz4ca5pfsr30c35feb4he2pssrxgn6vasbu1g7dfqm10c6xeeb4hw6df",
"MV Super-secret message transfer pasteboard type",
"dyn.ah62d4rv4gu8zg7puqz3c465fqr3gn7bakf41k55rqf4g86vasbu1g7dfqm10c6xeeb4hw6df",
"Super-secret Automator pasteboard type",
"dyn.ah62d4rv4gu8yc6durvwwa3xmrvw1gkdusm1044pxqyuha2pxsvw0e55bsmwca7d3sbwu",
"Apple files promise pasteboard type",
"public.url",
"CorePasteboardFlavorType 0x75726C20",
"dyn.ah62d4rv4gu8yc6durvwwaznwmuuha2pxsvw0e55bsmwca7d3sbwu",
"Apple URL pasteboard type",
"public.url-name",
"CorePasteboardFlavorType 0x75726C6E",
"com.apple.pasteboard.promised-file-content-type",
"com.apple.pasteboard.promised-file-url",
"dyn.ah62d4rv4gu8y6y4usm1044pxqzb085xyqz1hk64uqm10c6xenv61a3k",
NSPromiseContentsPboardType
)
Does anyone have any advice how to do this correctly in order to accept multiple e-mails?

Answer 1

I have found a solution to this. I found that the data provided in the mode "kUTTypeData" gave me enough data to grab the files directly from the mail.app mailbox.
In the mbox folder, there is a folder with a long sequence of numbers and dashes, there was no trace of this name anywhere in the mailbox hierarchy, but since this only contains this folder and an info.plist file, I used this function to grab that name: Update: implemented regexp check since the folder sometimes contains sub-mailboxes that can have a longer name...
-(NSString*)FindCodedFolderInMailbox:(NSString*)mailboxpath {
NSString *uuid_regexp = #"[A-F0-9]{8}-[A-F0-9]{4}-[A-F0-9]{4}-[A-F0-9]{4}-[A-F0-9]{12}";
NSPredicate *uuid_test = [NSPredicate predicateWithFormat:#"SELF MATCHES %#", uuid_regexp];
NSFileManager *fileManager = [NSFileManager defaultManager];
NSArray *fileList = [fileManager contentsOfDirectoryAtPath:mailboxpath error:nil];
for (NSString * file in fileList) {
if ([uuid_test evaluateWithObject: file]){
return file;
}
}
return nil;
}
Then the section where I find there is no "NSPromiseContentsPboardType", but instead a "Super-secret Automator pasteboard type", I wrote the following section (There is some NSLog entries I intend to remove, but here it is:
} else if ( [[pboard types] containsObject:#"Super-secret Automator pasteboard type"] ) {
NSFileManager *fileManager = [NSFileManager defaultManager];
// Create the URL for the destination folder and ensure it exists.
NSURL *applicationFilesDirectory = [self applicationFilesDirectory];
NSURL *url = [applicationFilesDirectory URLByAppendingPathComponent:#"documents"];
BOOL isDir;
if (!([fileManager fileExistsAtPath:[url path] isDirectory:&isDir] && isDir)) {
NSError * error = nil;
[ fileManager createDirectoryAtURL:url withIntermediateDirectories: YES attributes:nil error:&error];
if (error) {
[[NSApplication sharedApplication] presentError:error];
}
}
BOOL ok = false;
// locate the mailbox path....
NSString *mailboxpath = [pboard stringForType:#"MV Super-secret message transfer pasteboard type"];
NSLog(#"Mailboxpath: %#", mailboxpath);
NSString * codedFolder = [self FindCodedFolderInMailbox:mailboxpath];
if (codedFolder) {
NSString * codedpath = [NSString stringWithFormat:#"file://%#/%#/Data", mailboxpath, codedFolder];
NSURL * mb1 = [NSURL URLWithString:codedpath];
NSLog(#"Directory:%#", mb1);
NSArray *msgArray = [pboard propertyListForType:#"Super-secret Automator pasteboard type"];
if (msgArray) {
for (NSDictionary *msg in msgArray) {
// Locate the message....
NSNumber * msgID = [msg valueForKey:#"id"];
NSLog(#"Melding(%#):%#", msgID, msg);
NSString * filename = [NSString stringWithFormat:#"%#.emlx", msgID];
// second and first letter of id
NSString * idSec = [[msgID stringValue]substringWithRange:(NSRange){1, 1}];
NSString * idFirst = [[msgID stringValue]substringWithRange:(NSRange){0, 1}];
NSString * subpath = [NSString stringWithFormat:#"%#/%#/Messages/%#",idSec, idFirst, filename];
NSURL * thisFilePath = [mb1 URLByAppendingPathComponent:subpath];
if ([fileManager fileExistsAtPath:[thisFilePath path]]) {
NSURL *destpath = [url URLByAppendingPathComponent:filename];
NSError * error = nil;
[fileManager copyItemAtURL:thisFilePath toURL:destpath error:&error];
if (error) {
[[NSApplication sharedApplication]presentError:error];
} else {
[self ParseEmlMessageforPath:[destpath path] filename:filename];
}
}
}
}
}
And here we go.... :-)