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

    From KDE TechBase
    m (Text replace - "</code>" to "</syntaxhighlight>")
    (Use proper syntax highlighting and remove trailing whitespaces.)
    Line 1: Line 1:
    = Understanding =
    = 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:
    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*"
    <syntaxhighlight lang="text">
    ./lib/kde4/kio_imap4.so
    tweedleburg:/usr/local # find -iname "*imap4*"
    ./share/kde4/services/imap4.protocol
    ./lib/kde4/kio_imap4.so
    ./share/kde4/services/imap4.protocol
    </syntaxhighlight>


    = The files =
    = The files =
    Line 9: Line 11:


    == CMakeLists.txt ==
    == CMakeLists.txt ==
    <pre>
    <syntaxhighlight lang="cmake">
    PROJECT( tutorial )
    PROJECT( tutorial )
    FIND_PACKAGE(KDE4 REQUIRED)
    FIND_PACKAGE(KDE4 REQUIRED)
    Line 27: Line 29:


    install(FILES hello.protocol DESTINATION ${SERVICES_INSTALL_DIR})
    install(FILES hello.protocol DESTINATION ${SERVICES_INSTALL_DIR})
    </pre>
    </syntaxhighlight>


    == hello.h ==
    == hello.h ==
    Line 52: Line 54:
    <syntaxhighlight lang="cpp-qt">
    <syntaxhighlight lang="cpp-qt">
    #include "hello.h"
    #include "hello.h"
    #include <kdebug.h>  
    #include <kdebug.h>
    #include <kcomponentdata.h>
    #include <kcomponentdata.h>




    extern "C" int KDE_EXPORT kdemain( int argc, char **argv )
    extern "C" int KDE_EXPORT kdemain( int argc, char **argv )
    {                                  
    {
       kDebug(7000) << "Entering function";
       kDebug(7000) << "Entering function";
       KComponentData instance( "kio_hello" );
       KComponentData instance( "kio_hello" );


       if (argc != 4)  
       if (argc != 4)
       {
       {
         fprintf( stderr, "Usage: kio_hello protocol domain-socket1 domain-socket2\n");
         fprintf( stderr, "Usage: kio_hello protocol domain-socket1 domain-socket2\n");
    Line 86: Line 88:


    == hello.protocol ==  
    == hello.protocol ==  
    [Protocol]
    <syntaxhighlight lang="text">
    DocPath=kioslave/kio_hello.html  
    [Protocol]
    exec=kio_hello
    DocPath=kioslave/kio_hello.html
    input=none
    exec=kio_hello
    output=filesystem
    input=none
    protocol=hello
    output=filesystem
    reading=true
    protocol=hello
    reading=true
    </syntaxhighlight>


    == Compile the stuff ==
    == Compile the stuff ==
    Create a new Folder "build":
    Create a new Folder "build":
    <syntaxhighlight lang="text">
    <syntaxhighlight lang="bash">
    mkdir build
    mkdir build
    cd build
    cd build
    </syntaxhighlight>
    </syntaxhighlight>
    Run cmake and make
    Run cmake and make
    <syntaxhighlight lang="text">
    <syntaxhighlight lang="bash">
    cmake ..
    cmake ..
    make
    make
    Line 107: Line 111:


    now you can install it (maybe you should use an experimental setup?)
    now you can install it (maybe you should use an experimental setup?)
    <syntaxhighlight lang="text">
    <syntaxhighlight lang="bash">
    make install
    make install
    </syntaxhighlight>
    </syntaxhighlight>
    Line 113: Line 117:
    If you should want to do this by hand:
    If you should want to do this by hand:


    g++ -shared -lkdeui -lkio -lkdecore -fPIC -I/usr/local/include hello.cpp -o kio_hello.so
    <syntaxhighlight lang="bash">
    g++ -shared -lkdeui -lkio -lkdecore -fPIC -I/usr/local/include hello.cpp -o kio_hello.so
    </syntaxhighlight>


    ''this does not complile if the qt headers are not in /usr/local/include''
    ''this does not complile if the qt headers are not in /usr/local/include''
    Line 120: Line 126:
    == Install the stuff ==
    == Install the stuff ==


    now you can install it (maybe you should use an experimental setup?)
    Now you can install it (maybe you should use an experimental setup?):
    <syntaxhighlight lang="text">
    <syntaxhighlight lang="bash">
    make install
    make install
    </syntaxhighlight>
    </syntaxhighlight>


    or if you want to install it to your system:
    or if you want to install it to your system:
    <syntaxhighlight lang="text">
    <syntaxhighlight lang="bash">
    sudo make install
    sudo make install
    </syntaxhighlight>
    </syntaxhighlight>


    Of course you can also do this by hand
    Of course you can also do this by hand.


    Find out where your protocols are lying:
    Find out where your protocols are lying:
    kde4-config --path services
    <syntaxhighlight lang="bash">
    /usr/share/kde4/services/
    kde4-config --path services
      /usr/share/kde4/services/


    kde4-config --path module
    kde4-config --path module
    /usr/lib64/kde4/
      /usr/lib64/kde4/


    cp kio_hello.so /usr/local/lib/kde4/
    cp kio_hello.so /usr/local/lib/kde4/
    cp kio_hello.so /usr/lib64/kde4/
    cp kio_hello.so /usr/lib64/kde4/
    cp kio_hello.protocol /usr/share/kde4/services/
    cp kio_hello.protocol /usr/share/kde4/services/
    </syntaxhighlight>


    = Test it =
    = Test it =
    == in Konqueror ==
    == In Konqueror ==
    Start kinfocenter, choose hello as protocol. If this is possible, start konqueror, type hello:/// into the URL bar.
    Start kinfocenter, choose hello as protocol. If this is possible, start konqueror, type hello:/// into the URL bar.
    == on the command line ==
    == On the command line ==
    <syntaxhighlight lang="bash">
    kioclient 'cat' 'hello:///'
    kioclient 'cat' 'hello:///'
    </syntaxhighlight>

    Revision as of 12:52, 8 July 2011

    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 should want to do this by hand:

    g++ -shared -lkdeui -lkio -lkdecore -fPIC -I/usr/local/include 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

    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:///'