Overview

This artcile will help the developer to write an Qt program which performs the action of HTTP Get and Post. These two terms are very important when an web based application needs to be developed.

This is a very basic article this can be extended to suite the developers need.

Prerequisite

Install Qt for Symbian:Installing Qt on Symbian

					
					Note: 
					
							This code snippet is developed using carbide C++ v2.4.
						
							One can use Qt creator for developing this sort of application please go through this artcile for more details.

capability required

NetworkServices

UI design (.ui file)

The below screenshot shows the ui design file.

Header File

#ifndef MAINWINDOW_H #define MAINWINDOW_H   #include  #include  #include  #include  #include  
  namespace Ui { class MainWindow; }   class MainWindow : public QMainWindow { Q_OBJECT public: MainWindow(QWidget *parent = 0); ~MainWindow();   protected: void changeEvent(QEvent *e);   private slots: void finished(QNetworkReply *reply); void DoHttpGet(); void activateGetWidgets(); void HideWidgets(); void clearWidgets(); void activatePostWidgets();   private: Ui::MainWindow *ui;  
    QNetworkAccessManager *nam; };   #endif // MAINWINDOW_H
				

Source File

#include "mainwindow.h" #include "ui_mainwindow.h"  
MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent),
    ui(new Ui::MainWindow) { ui->setupUi(this);  
    nam = new QNetworkAccessManager(this); HideWidgets(); connect(ui->getButton,SIGNAL(clicked()),this,SLOT(activateGetWidgets())); connect(ui->submitButton,SIGNAL(clicked()),this,SLOT(DoHttpGet())); connect(ui->resetButton,SIGNAL(clicked()),this,SLOT(clearWidgets())); connect(nam,SIGNAL(finished(QNetworkReply*)),this,SLOT(finished(QNetworkReply*))); connect(ui->postButton,SIGNAL(clicked()),this,SLOT(activatePostWidgets())); }  
MainWindow::~MainWindow() { delete ui; }   void MainWindow::changeEvent(QEvent *e) { QMainWindow::changeEvent(e); switch (e->type()) { case QEvent::LanguageChange: ui->retranslateUi(this); break; default: break; } }   void MainWindow::activateGetWidgets() { ui->urlLabel->setHidden(false); ui->urlLine->setHidden(false); ui->submitButton->setHidden(false); ui->textBrowser->setHidden(false); ui->responseTitleLabel->setHidden(false); ui->getButton->setHidden(true); ui->postButton->setHidden(true);   }   void MainWindow::activatePostWidgets() { ui->dataLabel->setHidden(false); ui->dataLine->setHidden(false); activateGetWidgets();   }  
 
  void MainWindow::finished(QNetworkReply *reply) { if(reply->error() == QNetworkReply::NoError) { ui->textBrowser->setText(reply->readAll());   } else { ui->textBrowser->setText(reply->errorString()); } }   void MainWindow::DoHttpGet() { ui->resetButton->setHidden(false); QString url = ui->urlLine->text(); QString data = ui->dataLine->text(); QByteArray postData; postData.append(data.toAscii()); if(postData.isEmpty() == true) { nam->get(QNetworkRequest(QUrl(url))); } else { nam->post(QNetworkRequest(QUrl(url)),postData); }   }   void MainWindow::HideWidgets() { ui->urlLabel->setHidden(true); ui->urlLine->setHidden(true); ui->dataLabel->setHidden(true); ui->dataLine->setHidden(true); ui->submitButton->setHidden(true); ui->responseTitleLabel->setHidden(true); ui->textBrowser->setHidden(true); ui->resetButton->setHidden(true);   }   void MainWindow::clearWidgets() { ui->urlLabel->setHidden(true); ui->urlLine->setHidden(true); ui->dataLabel->setHidden(true); ui->dataLine->setHidden(true); ui->submitButton->setHidden(true); ui->responseTitleLabel->setHidden(true); ui->textBrowser->setHidden(true); ui->resetButton->setHidden(true); ui->urlLine->clear(); ui->textBrowser->clear(); ui->dataLine->clear(); ui->getButton->setHidden(false); ui->postButton->setHidden(false);   }
				

Output Screenshots

Initial Screen Asking the user to select and http get or post.

Screenshot after user has clicked the get button.

Screenshot after user has clicked the post button.

Sample Application

A sample Qt Application can be downloaded from this File:HttpGet&Post.zip

Reference Links

QNetworkAccessManager