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

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= 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 47: Line 49:
  
 
#endif
 
#endif
</code>
+
</syntaxhighlight>
  
 
== hello.cpp ==
 
== hello.cpp ==
 
<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 83: Line 85:
 
hello::hello( const QByteArray &pool, const QByteArray &app )
 
hello::hello( const QByteArray &pool, const QByteArray &app )
 
: SlaveBase( "hello", pool, app ) {}
 
: SlaveBase( "hello", pool, app ) {}
</code>
+
</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 ==
 
Create a new Folder "build":
 
Create a new Folder "build":
<code>
+
<syntaxhighlight lang="bash">
 
mkdir build
 
mkdir build
 
cd build
 
cd build
</code>
+
</syntaxhighlight>
 
Run cmake and make
 
Run cmake and make
<code>
+
<syntaxhighlight lang="bash">
 
cmake ..
 
cmake ..
 
make
 
make
</code>
+
</syntaxhighlight>
  
 
now you can install it (maybe you should use an experimental setup?)
 
now you can install it (maybe you should use an experimental setup?)
<code>
+
<syntaxhighlight lang="bash">
 
make install
 
make install
</code>
+
</syntaxhighlight>
  
 
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?):
<code>
+
<syntaxhighlight lang="bash">
 
make install
 
make install
</code>
+
</syntaxhighlight>
  
 
or if you want to install it to your system:
 
or if you want to install it to your system:
<code>
+
<syntaxhighlight lang="bash">
 
sudo make install
 
sudo make install
</code>
+
</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 13:52, 8 July 2011

Contents

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:///'

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