Development/Tutorials/Programming Tutorial KDE 3/KHTML: Difference between revisions

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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. So, this tutorial choses the khtml approach.  
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. So, this tutorial choses the khtml approach.  
=First step=
=First step=
Our first khtml-program does plain nothing:
This program shows you the first tags of an html file:
<highlightSyntax language="cpp">
'''tags.cpp'''
#include <qstring.h>
#include <kapplication.h>
#include <kaboutdata.h>
#include <kmessagebox.h>
#include <kcmdlineargs.h>
#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();
}
</highlightSyntax>
It can be compiled like:
gcc -I/usr/lib/qt3/include -I/opt/kde3/include \
-L/opt/kde3/lib -lkdeui -lkhtml -o khtml khtml.cpp
 
=Showing tags=
The next program is more advanced, it shows you the first tags of an html file:
<highlightSyntax language="cpp">
<highlightSyntax language="cpp">
#include <kapplication.h>
#include <kapplication.h>
Line 58: Line 35:
}
}
</highlightSyntax>
</highlightSyntax>
Compile it like this:
gcc -I/usr/lib/qt3/include -I/opt/kde3/include \
-L/opt/kde3/lib -lkdeui -lkhtml -o tags tags.cpp




Revision as of 22:35, 10 November 2006

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. So, this tutorial choses the khtml approach.

First step

This program shows you the first tags of an html file: tags.cpp <highlightSyntax language="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::Document* doc=new DOM::Document();
       DOM::DOMString tag("*");
       DOM::DOMString uri("<html>test</html>");
       doc->loadXML(uri);
       kdDebug() << "Does this doc have child elements ? " << doc->hasChildNodes() << endl;
       kdDebug() << "First child node name: " << doc->firstChild().nodeName().string() << endl;
       kdDebug() << "First grandchild node name: " << doc->firstChild().firstChild().nodeName().string() << endl;
       kdDebug() << "Count of elements in your doc " << doc->getElementsByTagName(tag).length()<< 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) << endl;
       kdDebug() << doc->toString().string() << endl;

} </highlightSyntax> Compile it like this: 

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


Non-conform syntax

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 here: <highlightSyntax language="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;

} </highlightSyntax>

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