Development/Tutorials/KIO Slaves/Hello World: Difference between revisions

    From KDE TechBase
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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
    </syntaxhighlight>
    </syntaxhighlight>


    ''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 ==



    Revision as of 12:34, 20 November 2012

    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*"
    ./lib/kde4/kio_imap4.so
    ./share/kde4/services/imap4.protocol
    

    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.

    CMakeLists.txt

    PROJECT( tutorial )
    FIND_PACKAGE(KDE4 REQUIRED)
    INCLUDE_DIRECTORIES( ${KDE4_INCLUDES} . )
    
    set(kio_hello_PART_SRCS
       hello.cpp)
    
    kde4_add_plugin(kio_hello ${kio_hello_PART_SRCS})
    
    target_link_libraries(kio_hello ${KDE4_KIO_LIBS})
    
    install(TARGETS kio_hello  DESTINATION ${PLUGIN_INSTALL_DIR})
    
    
    ########### install files ###############
    
    install(FILES hello.protocol DESTINATION ${SERVICES_INSTALL_DIR})
    

    hello.h

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

    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] );
      slave.dispatchLoop();
      return 0;
    }
    
    void hello::get( const KUrl &url )
    {
      kDebug(7000) << "Entering function";
      mimeType( "text/plain" );
      QByteArray str( "Hello_world" );
      data( str );
      finished();
      kDebug(7000) << "Leaving function";
    }
    
    hello::hello( const QByteArray &pool, const QByteArray &app )
    : SlaveBase( "hello", pool, app ) {}
    

    hello.protocol

    [Protocol]
    DocPath=kioslave/kio_hello.html
    exec=kio_hello
    input=none
    output=filesystem
    protocol=hello
    reading=true
    

    Compile the stuff

    Create a new Folder "build":

    mkdir build
    cd build
    

    Run cmake and make

    cmake ..
    make
    

    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
    

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

    Test it

    In Konqueror

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

    On the command line

    kioclient 'cat' 'hello:///'