URL

This documents research and notes around the URL specification.

Implementations

• http://trac.webkit.org/browser/trunk/Source/WebCore/platform/KURL.cpp
• http://trac.webkit.org/browser/trunk/Source/WebCore/platform/KURLWTFURL.cpp
• http://trac.webkit.org/browser/trunk/Source/WebCore/platform/KURLGoogle.cpp
• http://trac.webkit.org/browser/trunk/Source/WebCore/platform/network/DataURL.cpp (data URLs)

Tests

• https://github.com/cweb/iri-tests

Terminology

URL string

What you find in attribute values, property values, method parameters, etc.

parse a URL string url using base URL base

Turning a URL string into a URL by using a base URL.

URL

An in-memory representation of a URL with various properties as elaborated on by model below.

URL interface/object

JavaScript representation of a URL.

Model

URL (.href)
- invalid?
- scheme (.protocol)
- authority
  - username (proposed .username)
  - password (proposed .password)
  - ip/host (.hostname)
  - port (.port)
- path (.pathname)
- query (.search)
- fragment (.hash)

Parsing

parse (urlstr, optional baseURL)
 url = new URL
 tokenize(urlstr)

 SCHEME CHECK START
   if char is in ALPHA
     buffer += char
     -> SCHEME CHECK NEXT
   else
     unconsume char
     -> NO SCHEME

 SCHEME CHECK NEXT
   if char is in ALPHA / DIGIT / "+" / "-" / "."
     buffer += char
     -> continue
   elif char is ":"
     url.scheme = buffer.toASCIILowercase()
     buffer = ""
     -> SCHEME
   else:
     input.reset()
     -> NO SCHEME

 SCHEME
   if url.scheme is not hierarchical (data:)
     -> NON-HIERARCHICAL
   elif baseURL and url.scheme is baseURL.scheme (http:?test)
     -> RELATIVE
   else  (https://test.com/)
     -> AUTHORITY START

 NO SCHEME
   if not baseURL or baseURL.scheme is not hierarchical
     url.invalid = true
     return url
   else
     -> RELATIVE

 NON-HIERARCHICAL (could merge with PATH)
   if curChar is "#"
     FRAGMENT
   else
     ...

 RELATIVE
   if char is EOI (end-of-input)
     url = baseURL
     url.fragment = null
     exit

   elif char is "/" or char is "\"
     if next char "/" or next char is "\"
       url.scheme = baseURL.scheme
       -> AUTHORITY START
     else
       url.scheme = baseURL.scheme
       url.authority = baseURL.authority
       -> PATH

   elif char is "?"
       url.scheme = baseURL.scheme
       url.authority = baseURL.authority
       url.path = baseURL.path
       -> QUERY

   elif char is "#"
       url.scheme = baseURL.scheme
       url.authority = baseURL.authority
       url.path = baseURL.path
       url.query = baseURL.query
       -> FRAGMENT

   else
     url.scheme = baseURL.scheme
     url.authority = baseURL.authority
     prepend input by baseURL.path up to the last /
     -> PATH

 AUTHORITY START
   if char is "/" or char is "\"
     -> continue
   else
     -> AUTHORITY

 AUTHORITY
   ...

 PATH
   if char is "?"
     -> QUERY
   if char is "#"
     -> FRAGMENT
   else
     buffer += char

 QUERY
   if char is "#"
     -> FRAGMENT

 FRAGMENT
   ...