Xcode 9.2, iOS 11.2, Objective-C
Looking at the header for NSData, and base64EncodedStringWithOptions: NSDataBase64EncodingOptions,
the options are these starting on line 50 of NSData.h:
typedef NS_OPTIONS(NSUInteger, NSDataBase64EncodingOptions) {
// Use zero or one of the following to control the maximum line length after which a line ending is inserted. No line endings are inserted by default.
NSDataBase64Encoding64CharacterLineLength = 1UL << 0,
NSDataBase64Encoding76CharacterLineLength = 1UL << 1,
// Use zero or more of the following to specify which kind of line ending is inserted. The default line ending is CR LF.
NSDataBase64EncodingEndLineWithCarriageReturn = 1UL << 4,
NSDataBase64EncodingEndLineWithLineFeed = 1UL << 5,
}
Questions
- What did the deprecated base64Encoding do with the line endings? How long were lines and what happened at a line ending?
The typedef for NSDataBase64EncodingOptions, 0 is given the text, NSDataBase64Encoding64CharacterLineLength, indicating that a line is 64 characters.
The documentation for this states that “NSDataBase64Encoding64CharacterLineLength Set the maximum line length to 64 characters, after which a line ending is inserted.”.
The comment on line 52 for NSDataBase64Encoding64CharacterLineLength states something different. // Use zero or one of the following to control the maximum line length after which a line ending is inserted. No line endings are inserted by default.
It states that a line ending is inserted and no line endings are inserted by default.
- Which is the default value, 0? nil? I’d expect that it is 0, but the documentation for 0 states that a line ending is inserted and that no line endings are inserted by default. If 0 is the default, how is this possible?
- What happens for NSDataBase64Encoding76CharacterLineLength?
Can someone please clarify what Apple’s confusing documentation doesn’t?
Thank you,
Alex Zavatone
