Get body text from message URL in Swift - swift

Question

This question follows on from the question:
Drag messages from Mail onto Dock using Swift
I have now received a drag and drop message from dragging a message from Mail to the dock. The only thing that the I get is the message title and the message URL as follows:
message:%3C2004768713.4671#mail.stackoverflow.com%3E
How do I get the body text from this URL?
Thanks
Andrew

Answer 1

You can use a simple regular expression for this.
The .* parameter is hungry and will try to match as much as possible of the url subject:message pair before the (hopefully) last # character in the string.
I have also included a small tool function (rangeFromNSRange()) to help convert an Objective-C NSRange struct into a proper Range<String.Index> Swift struct.
Paste the following in a Swift playground to see it working (and have fun!):
import Cocoa
func rangeFromNSRange(range: NSRange, string: String) -> Range<String.Index>
{
let startIndex = string.startIndex.advancedBy(range.location)
let endIndex = startIndex.advancedBy(range.length)
return Range(start: startIndex, end: endIndex)
}
func parseEmailURL(urlAsString url: String) -> (subject: String, message: String)?
{
let regexFormat = "^(.*):(.*)#"
if let regex = try? NSRegularExpression(pattern: regexFormat, options: NSRegularExpressionOptions.CaseInsensitive)
{
let matches = regex.matchesInString(url, options: NSMatchingOptions(rawValue: 0), range: NSMakeRange(0, url.characters.count))
if let match = matches.first
{
let subjectRange = rangeFromNSRange(match.rangeAtIndex(1), string: url)
let messageRange = rangeFromNSRange(match.rangeAtIndex(2), string: url)
let subject = url.substringWithRange(subjectRange)
let message = url.substringWithRange(messageRange)
return (subject, message)
}
}
return nil
}
parseEmailURL(urlAsString: "message:2004768713.4671#mail.stackoverflow.com")