Difference between revisions of "Development/Tutorials/KIO Slaves/Hello World"

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(Use proper syntax highlighting and remove trailing whitespaces.)
(Compile the stuff: fix typo & use generic way to find Qt include dir)
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If you should want to do this by hand:
If you want to do this by hand:
<syntaxhighlight lang="bash">
<syntaxhighlight lang="bash">
g++ -shared -lkdeui -lkio -lkdecore -fPIC -I/usr/local/include hello.cpp -o kio_hello.so
g++ -shared -lkdeui -lkio -lkdecore -fPIC -I$(qmake -query QT_INSTALL_HEADERS) hello.cpp -o kio_hello.so
''this does not complile if the qt headers are not in /usr/local/include''
''On my system I could fix it by changing -I/usr/local/include to -I/usr/include/qt4''
== Install the stuff ==
== Install the stuff ==

Latest revision as of 13:34, 20 November 2012


[edit] Understanding

A kioslave allows you to represent any kind of storage in a way you want. As an example, the kio_http kioslave loads data from the network over the http (protocol) and shows it rendered as html. Technically, a kioslave is a shared object plus its description. E.g. the imap4 kioslave consist of the following files:

tweedleburg:/usr/local # find -iname "*imap4*"

[edit] The files

We want to write a "hello world" kioslave here. This can be seen as a learning exercise and as a template for future programming projects.

[edit] CMakeLists.txt

PROJECT( tutorial )
kde4_add_plugin(kio_hello ${kio_hello_PART_SRCS})
target_link_libraries(kio_hello ${KDE4_KIO_LIBS})
########### install files ###############

[edit] hello.h

#ifndef HELLO_H
#define HELLO_H
#include <kio/slavebase.h>
  This class implements a hello-world kioslave
class hello : public KIO::SlaveBase
    hello( const QByteArray &pool, const QByteArray &app );
    void get( const KUrl &url );

[edit] hello.cpp

#include "hello.h"
#include <kdebug.h>
#include <kcomponentdata.h>
extern "C" int KDE_EXPORT kdemain( int argc, char **argv )
  kDebug(7000) << "Entering function";
  KComponentData instance( "kio_hello" );
  if (argc != 4)
    fprintf( stderr, "Usage: kio_hello protocol domain-socket1 domain-socket2\n");
    exit( -1 );
  hello slave( argv[2], argv[3] );
  return 0;
void hello::get( const KUrl &url )
  kDebug(7000) << "Entering function";
  mimeType( "text/plain" );
  QByteArray str( "Hello_world" );
  data( str );
  kDebug(7000) << "Leaving function";
hello::hello( const QByteArray &pool, const QByteArray &app )
: SlaveBase( "hello", pool, app ) {}

[edit] hello.protocol


[edit] Compile the stuff

Create a new Folder "build":

mkdir build
cd build

Run cmake and make

cmake ..

now you can install it (maybe you should use an experimental setup?)

make install

If you want to do this by hand:

g++ -shared -lkdeui -lkio -lkdecore -fPIC -I$(qmake -query QT_INSTALL_HEADERS) hello.cpp -o kio_hello.so

[edit] Install the stuff

Now you can install it (maybe you should use an experimental setup?):

make install

or if you want to install it to your system:

sudo make install

Of course you can also do this by hand.

Find out where your protocols are lying:

kde4-config --path services
kde4-config --path module
cp kio_hello.so /usr/local/lib/kde4/
cp kio_hello.so /usr/lib64/kde4/
cp kio_hello.protocol /usr/share/kde4/services/

[edit] Test it

[edit] In Konqueror

Start kinfocenter, choose hello as protocol. If this is possible, start konqueror, type hello:/// into the URL bar.

[edit] On the command line

kioclient 'cat' 'hello:///'

This page was last modified on 20 November 2012, at 13:34. This page has been accessed 11,324 times. Content is available under Creative Commons License SA 3.0 as well as the GNU Free Documentation License 1.2.
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