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

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{{Review|Port to KF5}}
= 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 13:


== CMakeLists.txt ==
== CMakeLists.txt ==
<pre>
<syntaxhighlight lang="cmake">
PROJECT( tutorial )
PROJECT( tutorial )
FIND_PACKAGE(KDE4 REQUIRED)
FIND_PACKAGE(KDE4 REQUIRED)
Line 27: Line 31:


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


== hello.h ==
== hello.h ==
<pre>
<syntaxhighlight lang="cpp-qt">
#ifndef HELLO_H
#ifndef HELLO_H
#define HELLO_H
#define HELLO_H
Line 42: Line 46:
{
{
   public:
   public:
    hello( const QByteArray &pool, const QByteArray &app );
     void get( const KUrl &url );
     void get( const KUrl &url );
    hello( const QString &pool, const QString &app );
};
};


#endif
#endif
</pre>
</syntaxhighlight>


== hello.cpp ==
== hello.cpp ==
<pre>
<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 83: Line 87:
hello::hello( const QByteArray &pool, const QByteArray &app )
hello::hello( const QByteArray &pool, const QByteArray &app )
: SlaveBase( "hello", pool, app ) {}
: SlaveBase( "hello", pool, app ) {}
</pre>
</syntaxhighlight>


== 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 ==
g++ -shared -lkdeui -lkio -lkdecore -fPIC -I/usr/local/include hello.cpp -o kio_hello.so
Create a new Folder "build":
<syntaxhighlight lang="bash">
mkdir build
cd build
</syntaxhighlight>
Run cmake and make
<syntaxhighlight lang="bash">
cmake ..
make
</syntaxhighlight>
 
now you can install it (maybe you should use an experimental setup?)
<syntaxhighlight lang="bash">
make install
</syntaxhighlight>
 
If you want to do this by hand:
 
<syntaxhighlight lang="bash">
g++ -shared -lkdeui -lkio -lkdecore -fPIC -I$(qmake -query QT_INSTALL_HEADERS) hello.cpp -o kio_hello.so
</syntaxhighlight>


== Install the stuff ==
== Install the stuff ==
Now you can install it (maybe you should use an experimental setup?):
<syntaxhighlight lang="bash">
make install
</syntaxhighlight>
or if you want to install it to your system:
<syntaxhighlight lang="bash">
sudo make install
</syntaxhighlight>
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
  /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 ==
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 ==
<syntaxhighlight lang="bash">
kioclient 'cat' 'hello:///'
</syntaxhighlight>

Latest revision as of 12:43, 31 May 2019

Warning
This page needs a review and probably holds information that needs to be fixed.

Parts to be reviewed:

Port to KF5

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:///'