A qt-interest mail archive search

This example does a search on the qt-interest mailinglist archives. It uses QHttp to issue the search command and to fetch the results. The GUI parts were done using Qt Designer.

The implementation of the HTTP requests (archivedialog.ui.h):

/****************************************************************************
** $Id$
**
** Copyright (C) 1992-2003 Trolltech AS.  All rights reserved.
**
** This file is part of an example program for Qt.  This example
** program may be used, distributed and modified without limitation.
**
*****************************************************************************/

/****************************************************************************
** ui.h extension file, included from the uic-generated form implementation.
**
** If you wish to add, delete or rename functions or slots use
** Qt Designer which will update this file, preserving your code. Create an
** init() function in place of a constructor, and a destroy() function in
** place of a destructor.
*****************************************************************************/

void ArchiveDialog::init()
{
    connect(&articleSearcher, SIGNAL(done(bool)), this, SLOT(searchDone(bool)));
    connect(&articleFetcher, SIGNAL(done(bool)), this, SLOT(fetchDone(bool)));
    connect(myListView, SIGNAL(selectionChanged(QListViewItem*)), this, SLOT(fetch(QListViewItem*)));
    connect(myLineEdit, SIGNAL(returnPressed()), this, SLOT(search()));
    connect(myListView, SIGNAL(returnPressed(QListViewItem*)), this, SLOT(fetch(QListViewItem*)));
    connect(myPushButton, SIGNAL(clicked()), this, SLOT(close()));
}

void ArchiveDialog::fetch( QListViewItem *it )
{
    QUrl u(it->text(1));
    articleFetcher.setHost(u.host());
    articleFetcher.get(it->text(1));
}

void ArchiveDialog::fetchDone( bool error )
{
    if (error) {
        QMessageBox::critical(this, "Error fetching",
                              "An error occurred when fetching this document: "
                              + articleFetcher.errorString(),
                              QMessageBox::Ok, QMessageBox::NoButton);
    } else {
        myTextBrowser->setText(articleFetcher.readAll());
    }
}

void ArchiveDialog::search()
{
    if (articleSearcher.state() == QHttp::HostLookup
        || articleSearcher.state() == QHttp::Connecting
        || articleSearcher.state() == QHttp::Sending
        || articleSearcher.state() == QHttp::Reading) {
        articleSearcher.abort();
    }

    if (myLineEdit->text() == "") {
        QMessageBox::critical(this, "Empty query",
                              "Please type a search string.",
                              QMessageBox::Ok, QMessageBox::NoButton);
    } else {
        QApplication::setOverrideCursor(QCursor(Qt::WaitCursor));

        articleSearcher.setHost("www.trolltech.com");

        QHttpRequestHeader header("POST", "/search.html");
        header.setValue("Host", "www.trolltech.com");
        header.setContentType("application/x-www-form-urlencoded");

        QString encodedTopic = myLineEdit->text();
        QUrl::encode(encodedTopic);
        QString searchString = "qt-interest=on&search=" + encodedTopic;

        articleSearcher.request(header, searchString.utf8());
    }

}

void ArchiveDialog::searchDone( bool error )
{
    if (error) {
        QMessageBox::critical(this, "Error searching",
                              "An error occurred when searching: "
                              + articleSearcher.errorString(),
                              QMessageBox::Ok, QMessageBox::NoButton);
    } else {
        QString result(articleSearcher.readAll());

        QRegExp rx("<a href=\"(http://lists\\.trolltech\\.com/qt-interest/.*)\">(.*)</a>");
        rx.setMinimal(TRUE);
        int pos = 0;
        while (pos >= 0) {
            pos = rx.search(result, pos);
            if (pos > -1) {
                pos += rx.matchedLength();
                new QListViewItem(myListView, rx.cap(2), rx.cap(1));
            }
        }
    }

    QApplication::restoreOverrideCursor();
}

Main (main.cpp):

/****************************************************************************
** $Id$
**
** Copyright (C) 1992-2003 Trolltech AS.  All rights reserved.
**
** This file is part of an example program for Qt.  This example
** program may be used, distributed and modified without limitation.
**
*****************************************************************************/

#include "archivedialog.h"
#include <qapplication.h>

int main(int argc, char **argv)
{
    QApplication a( argc, argv );
    ArchiveDialog ad;
    ad.show();

    QObject::connect( &a, SIGNAL(lastWindowClosed()),
                      &a, SLOT(quit()) );

    return a.exec();
}

See also Network Examples.