Issue compiling hello world on Wt - wt

Question

I try to compile a hello world like application using Wt but have problems to link
I use Qt creator and mingw32 as compiler
what am I doing wrong ? Any help will be appreciated
The process "C:/MinGW32/bin/mingw32-make.exe" exited normally.
Configuration unchanged, skipping qmake step.
Starting: "C:/MinGW32/bin/mingw32-make.exe" -w
mingw32-make: Entering directory `C:/Wt/HelloWt-build-desktop'
C:/MinGW32/bin/mingw32-make -f Makefile.Debug
mingw32-make[1]: Entering directory `C:/Wt/HelloWt-build-desktop'
g++ -c -DNDEBUG -g -frtti -fexceptions -mthreads -Wall -DUNICODE -DQT_LARGEFILE_SUPPORT -D__MINGW32__ -D_WIN32 -DQT_DLL -DQT_NETWORK_LIB -DQT_CORE_LIB -DQT_THREAD_SUPPORT -I'../../Qt/2010.05/qt/include/QtCore' -I'../../Qt/2010.05/qt/include/QtNetwork' -I'../../Qt/2010.05/qt/include' -I'../../Wt2/Include' -I'../../boost/include/boost-1_45' -I'../../Qt/2010.05/qt/include/ActiveQt' -I'debug' -I'../../WtTest/HelloWt' -I'.' -I'../../Qt/2010.05/qt/mkspecs/win32-g++' -o debug/main.o ../../WtTest/HelloWt/main.cpp
g++ -enable-stdcall-fixup -Wl,-enable-auto-import -Wl,-enable-runtime-pseudo-reloc -Wl,-subsystem,console -mthreads -Wl -o debug/HelloWt.exe debug/main.o -L'c:/Qt/2010.05/qt/lib' C:\Wt2\lib\libwt.a C:\Wt2\lib\libwthttp.a C:\QtSDK\mingw\lib\libws2_32.a C:\QtSDK\mingw\lib\libwsock32.a C:\boost\lib\libboost_thread-mgw45-mt-d-1_45.a C:\boost\lib\libboost_regex-mgw45-mt-d-1_45.a C:\boost\lib\libboost_date_time-mgw45-mt-d-1_45.a C:\boost\lib\libboost_signals-mgw45-mt-d-1_45.a C:\boost\lib\libboost_system-mgw45-mt-d-1_45.a C:\boost\lib\libboost_program_options-mgw45-mt-d-1_45.a C:\boost\lib\libboost_filesystem-mgw45-mt-d-1_45.a -lQtNetworkd4 -lQtCored4
mingw32-make[1]: Leaving directory `C:/Wt/HelloWt-build-desktop'
mingw32-make: Leaving directory `C:/Wt/HelloWt-build-desktop'
C:\Wt2\lib\libwthttp.a(WServer.obj): In function `WServer':
C:/wt-3.1.9/src/http/WServer.C:142: undefined reference to `Wt::WAbstractServer::instance_'
C:/wt-3.1.9/src/http/WServer.C:140: undefined reference to `Wt::WAbstractServer::~WAbstractServer()'
C:\Wt2\lib\libwthttp.a(WServer.obj): In function `~HTTPStream':
C:/wt-3.1.9/src/http/HTTPStream.h:16: undefined reference to `Wt::WebStream::~WebStream()'
C:\Wt2\lib\libwthttp.a(WServer.obj): In function `~WServer':
C:/wt-3.1.9/src/http/WServer.C:145: undefined reference to `Wt::WAbstractServer::~WAbstractServer()'
C:\Wt2\lib\libwthttp.a(WServer.obj): In function `~HTTPStream':
C:/wt-3.1.9/src/http/HTTPStream.h:16: undefined reference to `Wt::WebStream::~WebStream()'
C:\Wt2\lib\libwthttp.a(WServer.obj): In function `~WServer':
C:/wt-3.1.9/src/http/WServer.C:145: undefined reference to `Wt::WAbstractServer::~WAbstractServer()'
C:\Wt2\lib\libwthttp.a(HTTPStream.obj): In function `HTTPStream':
C:/wt-3.1.9/src/http/HTTPStream.C:17: undefined reference to `Wt::WebStream::WebStream(bool)'
C:\Wt2\lib\libwthttp.a(HTTPStream.obj): In function `~HTTPStream':
C:/wt-3.1.9/src/http/HTTPStream.h:16: undefined reference to `Wt::WebStream::~WebStream()'
C:/wt-3.1.9/src/http/HTTPStream.h:16: undefined reference to `Wt::WebStream::~WebStream()'
collect2: ld returned 1 exit status
mingw32-make[1]: *** [debug/HelloWt.exe] Error 1
mingw32-make: *** [debug] Error 2
The process "C:/MinGW32/bin/mingw32-make.exe" exited with code %2.
Error while building project HelloWt (target: Desktop)
When executing build step 'Make'
Here is the source
#include <Wt/WApplication>
#include <Wt/WBreak>
#include <Wt/WContainerWidget>
#include <Wt/WLineEdit>
#include <Wt/WPushButton>
#include <Wt/WText>
#include <boost/version.hpp>
using namespace Wt;
/*
* A simple hello world application class which demonstrates how to react
* to events, read input, and give feed-back.
*/
class HelloApplication : public WApplication
{
public:
HelloApplication(const WEnvironment& env);
private:
WLineEdit *nameEdit_;
WText *greeting_;
void greet();
};
/*
* The env argument contains information about the new session, and
* the initial request. It must be passed to the WApplication
* constructor so it is typically also an argument for your custom
* application constructor.
*/
HelloApplication::HelloApplication(const WEnvironment& env)
: WApplication(env)
{
setTitle("Hello world"); // application title
root()->addWidget(new WText("Your name, please ? ")); // show some text
nameEdit_ = new WLineEdit(root()); // allow text input
nameEdit_->setFocus(); // give focus
WPushButton *b = new WPushButton("Greet me.", root()); // create a button
b->setMargin(5, Left); // add 5 pixels margin
root()->addWidget(new WBreak()); // insert a line break
greeting_ = new WText(root()); // empty text
/*
* Connect signals with slots
*
* - simple Wt-way
*/
b->clicked().connect(this, &HelloApplication::greet);
/*
* - using an arbitrary function object (binding values with boost::bind())
*/
nameEdit_->enterPressed().connect
(boost::bind(&HelloApplication::greet, this));
}
void HelloApplication::greet()
{
/*
* Update the text, using text input into the nameEdit_ field.
*/
greeting_->setText("Hello there, " + nameEdit_->text());
}
WApplication *createApplication(const WEnvironment& env)
{
/*
* You could read information from the environment to decide whether
* the user has permission to start a new application
*/
return new HelloApplication(env);
}
int main(int argc, char **argv)
{
/*
* Your main method may set up some shared resources, but should then
* start the server application (FastCGI or httpd) that starts listening
* for requests, and handles all of the application life cycles.
*
* The last argument to WRun specifies the function that will instantiate
* new application objects. That function is executed when a new user surfs
* to the Wt application, and after the library has negotiated browser
* support. The function should return a newly instantiated application
* object.
*/
return WRun(argc, argv, &createApplication);
}

Answer 1

You may need to reverse the order of libwt.a and libwthttp.a on your command line. The order of arguments sometimes matters to the GNU linker.

Answer 2

You are trying to link you application with QtCore, QtNetwork and ActiveQt libraries, and not with Wt libraries.
As far as I can see you are unsing qmake and then make.
If you do, check you project configuration file, and compare with Hello World example of Wt used with qmake:
QT -= core
QT -= gui
TARGET = CppHelloWtQtCreatorUbuntu
LIBS += -L/usr/lib -lwt -lwthttp
QMAKE_CXXFLAGS += -DNDEBUG
CONFIG += console
CONFIG -= app_bundle
TEMPLATE = app
SOURCES += main.cpp \
wittyapplication.cpp
HEADERS += \
wittyapplication.h
As you can see here, all linking with Qt libraries are removed and added wt and wthttp (to have binary witch is a standalone webserver) libs.
Also make shure you have Wt header files accesible via INCLUDE enviroment variable and Wt libraries are acessibe via PATH enviroment variable.