{"id":16521,"date":"2016-12-02T14:19:14","date_gmt":"2016-12-02T19:19:14","guid":{"rendered":"http:\/\/mjtsai.com\/blog\/?p=16521"},"modified":"2019-01-08T13:39:25","modified_gmt":"2019-01-08T18:39:25","slug":"file-reference-urls-dont-work-in-swift-3","status":"publish","type":"post","link":"https:\/\/mjtsai.com\/blog\/2016\/12\/02\/file-reference-urls-dont-work-in-swift-3\/","title":{"rendered":"File Reference URLs Don’t Work in Swift 3"},"content":{"rendered":"

SR-2728<\/a>:<\/p>\n

\n

In Swift 3.0 (i.e. Xcode 8.0 or Xcode 8.1 beta 1), a call to fileReferenceURL<\/code> does not<\/em> give a file reference URL anymore... this code<\/p>\n

import Foundation\nlet string = \"file:\/\/\/Users\/admin\"\nif let url = NSURL(string: string) {\n  if let ref = url.fileReferenceURL() {\n    print (\"ref = (ref)\")\n  }\n}\n<\/pre>\n
prints<\/p>\n
ref = file:\/\/\/Users\/admin\/<\/pre>\n
while it should have been printing<\/p>\n
ref = file:\/\/\/.file\/id=6571367.437879\/<\/pre>\n
as it did, correctly, in Swift 2.2 (and before) in Xcode 7.3.1 for example.<\/p>\n<\/blockquote>\n
Via Charles Srstka<\/a>:<\/p>\n
.fileReferenceURL<\/code> doesn’t exist on URL<\/code>. It does exist on NSURL<\/code>, but thanks to the bridging magic it returns a URL<\/code>, which the ObjC-Swift bridge turns into a normal file path URL.<\/p><\/blockquote>\n
Frédéric Blondiau has some<\/a> workarounds<\/a>, but these are distasteful to me because they rely on the internal details of both NSURLFileResourceIdentifierKey<\/code> and file reference URLs<\/a>.<\/p>\n
It seems like the proper short-term solution would be to write some Objective-C code to return an object that is not bridged to URL<\/code>. This could probably be the actual NSURL<\/code> typed as id<\/code>. Or, if you’re going to use an opaque token anyway, another option would be to store bookmark data. I assume that would be slower, though.<\/p>\n\n
Update (2018-09-08): Christian Tietze<\/a>:<\/p>\n
Swift 4.1 has a simpler mechanism to ensure you get a NSURL<\/code> instead of a URL<\/code> – the only type that supports file reference URLs as of September 2018, still.<\/p>\n
if let fileRefURL = (url as NSURL).fileReferenceURL() as NSURL? { \n    print(fileRefURL)\n}<\/pre>\n
Try that in the Swift 4.1 REPL to see that it works. Whew.<\/p>
I do understand that there may be reasons to remove fileReferenceURL<\/code> from URL<\/code> and leave it on NSURL<\/code>, but when you do<\/em> invoke it on NSURL<\/code>, I think it should at least return another NSURL<\/code> object that works as expected instead of bridging to Swift’s URL<\/code> struct that, for some reason, won’t work.<\/p><\/blockquote>\n\n
Update (2019-01-08): Jens Ayton<\/a>:<\/p>\n
\n
No, wait! It actually crashes when you bridge the file reference NSURL<\/code> to URL<\/code>.<\/p>\n<\/blockquote>","protected":false},"excerpt":{"rendered":"
SR-2728: In Swift 3.0 (i.e. Xcode 8.0 or Xcode 8.1 beta 1), a call to fileReferenceURL does not give a file reference URL anymore... this code import Foundation let string = \"file:\/\/\/Users\/admin\" if let url = NSURL(string: string) { if let ref = url.fileReferenceURL() { print (\"ref = (ref)\") } } prints ref = file:\/\/\/Users\/admin\/ […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"apple_news_api_created_at":"2018-09-08T19:23:54Z","apple_news_api_id":"f28140d3-230a-4751-a80f-a21ff706c76c","apple_news_api_modified_at":"2019-01-08T18:39:29Z","apple_news_api_revision":"AAAAAAAAAAAAAAAAAAAAAA==","apple_news_api_share_url":"https:\/\/apple.news\/A8oFA0yMKR1GoD6If9wbHbA","apple_news_coverimage":0,"apple_news_coverimage_caption":"","apple_news_is_hidden":false,"apple_news_is_paid":false,"apple_news_is_preview":false,"apple_news_is_sponsored":false,"apple_news_maturity_rating":"","apple_news_metadata":"\"\"","apple_news_pullquote":"","apple_news_pullquote_position":"","apple_news_slug":"","apple_news_sections":"\"\"","apple_news_suppress_video_url":false,"apple_news_use_image_component":false,"footnotes":""},"categories":[4],"tags":[131,69,31,1380,30,1381,54,71,901,489],"class_list":["post-16521","post","type-post","status-publish","format-standard","hentry","category-programming-category","tag-bug","tag-cocoa","tag-ios","tag-ios-10","tag-mac","tag-macos-10-12","tag-objective-c","tag-programming","tag-swift-programming-language","tag-url"],"apple_news_notices":[],"_links":{"self":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts\/16521","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/comments?post=16521"}],"version-history":[{"count":3,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts\/16521\/revisions"}],"predecessor-version":[{"id":23881,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts\/16521\/revisions\/23881"}],"wp:attachment":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/media?parent=16521"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/categories?post=16521"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/tags?post=16521"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}