A simple C++ URL class

The Url object API

Url is a C++ URL handling class with a very simple API. It's use is straigthforward.

• Construct an Url object

  Url u1;
  Url u2("http://www.example.com/");
  Url u3(u2);

• Assigning an url to an Url object

  u1=u2;
  u2="http://www.example.com/";

• Getting the url as a string

  std::string url_str=url.str();

• Clearing an Url object

  u1.clear();

• Getting the different fields of an Url object

  std::string scheme_str=u1.scheme();
  std::string user_info_str=u1.user_info();
  std::string host_str=u1.host();
  std::uint8_t ip_version=u1.ip_version();
  // 0=name, 4=IPv4, 6=IPv6,-1=undefined
  std::string port_str=u1.port();
  std::string path_str=u1.path();
  Url::Query query=u1.query();
  std::string fragment_str=u1.fragment();

• Setting the different fields of an Url object

  u1.clear().scheme("http").host("www.example.com").path("/");
  u1.add_query("q","some search key").add_query("fast");
  assert(u1.str()=="http://www.example.com/?q=some+search+key&fast");

• Accessing the key and values in the query

  u1.clear().add_query("a","b").add_query("c","d");
  assert(u1.query(0).val()=="b");
  assert(u1.query(1).key()=="c");
  assert(u1.str()=="?a=b&c=d");
  u1.set_query(0).val("B");
  u1.set_query(1).key("C");
  assert(u1.str()=="?a=B&C=d");

• Output of an Url object

  u1.str("http://www.example.com/?q=some+search+key&fast");
  std::stringstream str;
  str << u1;
  assert(str.str()=="Url:{url(http://www.example.com/?q=some+search+key&fast) "
         "scheme(http) host(www.example.com) IPv(0) path(/) "
         "query(<key(q) val(some search key)> <key(fast) val()>)}");

Implementation detail

The Url object uses lazy URL parsing and building. When a URL as string is assigned to the object, it is not immediatly parsed. It can then be assigned or moved to another Url object efficiently. The URL is parsed only when needed, which is before one of the fields is accessed or set, or when the object is output.

The URL is built only when the str() method is called or when the Url object is output.