opening files with different extensions with Cocoa

Question

I have an NSDocument based app that already handles *.txt files. I can drag and drop those files in the dock and my app will launch correctly.

Now I want to be able to open *.text files too. So I have added:

<key>CFBundleTypeExtensions</key>
    <array>
        <string>.txt</string>
        <string>.text</string>
    </array>

to my *plist

However I can't open *.text files by drag&dropping them in the dock. (I can do MyApp> File>Open> myFile.text ) I can open *.txt as usual, and drag and drop them in the dock.

I have tried implementing these NSApp delegate methods but now I get an error and I can't open any kind of file.

- (BOOL)application:(NSApplication *)theApplication openFile:(NSString *)filename{
    NSURL *url = [NSURL URLWithString:filename];
    NSError *error = nil;
    [[NSDocumentController sharedDocumentController] openDocumentWithContentsOfURL:url display:YES error:&error];
    if (error) {
        NSLog(@"error: %@", [error localizedDescription]);
        error = nil;
        return NO;
    }
    return YES;
}

- (void)application:(NSApplication *)sender openFiles:(NSArray *)filenames{
    for (NSString *filename in filenames) {
        [self application:sender openFile:filename];
    }
}

Error:

typeForContentsOfURL:error: must be overridden for your application to support non-'file:' URLs.

I am not subclassing NSDocumentController, so do I really need to? or is there a better/easier way of doing this?

Thanks in advance

Rob Keniger Rob Keniger · Accepted Answer · 2011-06-06T07:37:59

The file extensions in the Info.plist file should not contain a period character (.). What happens if you do this?:

<key>CFBundleTypeExtensions</key>
    <array>
        <string>txt</string>
        <string>text</string>
    </array>

opening files with different extensions with Cocoa

1 Answers