The HTMLPage class

Design and implement a class called HTMLPage which inherits from FileParser. It should have the following functionality: opens an HTML file (of which the URL is known), reads and stores its links (transforming relative links into absolute links), allows external access to the stored links. This class is derived from FileParser because it uses FileParser's functionality in a specific manner, performing some specific task (relative links are transformed into absolute links) of which FileParser knows nothing about.

• A link in an HTML page is the value in the tag href="value" (or simply href=value). HTML is a case insensitive language, so you may also find HREF instead of href.
• A WWW link is absolute if it starts with http:// and a DNS name and is relative otherwise. Given a relative link (i.e. not starting with a slash '/' character, e.g. liberti/index.html) and an absolute link (e.g. http://www.lix.polytechnique.fr/users), the relative link is transformed into an absolute link by concatenating the two URLs (absolute and relative) with any missing slashes in between (e.g. http://www.lix.polytechnique.fr/users/liberti/index.html. On the other hand, if the relative link starts with a slash '/' (e.g. / liberti/index.html) then the transformation of the relative link to absolute occurs by concatenating the first part of the absolute link (up to and including the DNS name) and the relative one (e.g. http://www.lix.polytechnique.fr/~liberti/index.html).
• Remember that not all links found next to HREF tags are valid HTTP links, some may concern different protocols. You should make sure that the link introduced by HREF is either relative (in which case you should make it absolute as explained above) or specifically an http link.
• Test your class implementation using the following driver hpdriver.cxx:
  

  #include<iostream>
  #include "htmlpage.h"
  
  int main(int argc, char** argv) {
    using namespace std;
    if (argc < 3) {
      cerr << "missing 2 args on cmd line" << endl;
      return 1;
    }
    HTMLPage hp(argv[2], argv[1]);
    for(int i = 0; i < hp.getNumberOfLinks(); i++) {
      cout << hp.getLink(i) << endl;
    }
    return 0;
  }
  

  and check that the output of the command is

  http://mywebsite.com/mywebpage.html
  http://127.0.0.1/otherfile.html