Development/Tutorials/Programming Tutorial KDE 3/KHTML

    From KDE TechBase
    Revision as of 16:56, 9 December 2009 by Rakuco (talk | contribs) (Fix typo)

    For HTML parsing, you have the following possibilities:

    • QXML
    • QDOM
    • perl
    • khtml

    Obviously, QXML and QDOM need xml-compliant html pages, and the least html pages are xml-compliant. Perl is not the scope of this site. This tutorial chooses the khtml approach.

    First step

    As we remember from http://developernew.kde.org/Development/Tutorials/Programming_Tutorial_KDE_4/How_to_write_an_HTML_parser, biggest thing is to be able to parse non-XML-conform syntax. It works with the following program.

    tags.cpp

    1. include <kapplication.h>
    2. include <kaboutdata.h>
    3. include <kcmdlineargs.h>
    4. include <dom/html_document.h>

    int main (int argc, char *argv[]) {

           KAboutData aboutData( "test", "test",
           "1.0", "test", KAboutData::License_GPL,
           "(c) 2006" );
           KCmdLineArgs::init( argc, argv, &aboutData );
           KApplication khello;
    
           DOM::HTMLDocument doc;
           DOM::DOMString tag("*");
           DOM::DOMString uri("<html><body><a href=\"http://www.kde.org/\"></a><a href=\"/index.php\" nowrap>Log in</a><a href=\"http://www.gmx.de\"></a></body></html>");
    
           doc.loadXML(uri);
           kdDebug() << "Does this doc have child elements ? " << doc.hasChildNodes() << endl;
           for (int i=0; i<doc.getElementsByTagName(tag).length(); i++) kdDebug() << doc.getElementsByTagName(tag).item(i).nodeName().string() << endl;
           kdDebug() << "Size of your doc " << sizeof(doc.firstChild()) << endl;
           kdDebug() << doc.isHTMLDocument() << endl;
           kdDebug() << doc.toString().string() << endl;
    

    }


    Compile it like this:

    gcc -I/usr/lib/qt3/include -I/opt/kde3/include \
    -L/opt/kde3/lib -lkdeui -lkhtml -o tags tags.cpp
    

    Second

    1. include <kapplication.h>
    2. include <kaboutdata.h>
    3. include <kcmdlineargs.h>
    4. include <dom/html_document.h>
    5. include <dom/html_element.h>
    6. include <dom/dom_node.h>

    int main (int argc, char *argv[]) {

           KAboutData aboutData( "test", "test",
           "1.0", "test", KAboutData::License_GPL,
           "(c) 2006" );
           KCmdLineArgs::init( argc, argv, &aboutData );
           KApplication khello;
    
           DOM::HTMLDocument doc;
           DOM::DOMString tag("*");
           DOM::DOMString uri("<html><body><a href=\"http://www.kde.org/\">fat</a><a href=\"/index.php\" nowrap>Log in</a><a href=\"http://www.gmx.de\"></a></body></html>");
    
           doc.loadXML(uri);
           kdDebug() << "Here's a list of the document elements" << endl;
           for (int i=0; i<doc.getElementsByTagName(tag).length(); i++) kdDebug() << doc.getElementsByTagName(tag).item(i).nodeName().string() << endl;
          
           DOM::HTMLDocument doc2;
           DOM::DOMString uri2("<html><body>this is htmlfat</body></html>");
           doc2.loadXML(uri2);
           kdDebug() << "This is the in-memory html:" << endl;
           kdDebug() << doc.toString().string() << endl;
           doc.body().insertBefore(doc.body().firstChild().firstChild(),doc.body().firstChild());
           kdDebug() << "Moving around nodes" << endl;
           kdDebug() << doc.toString().string() << endl;
    

    }