In this entry I’m going to create a simple form. This form will show you how to use controls and events in a very simple way.

A couple things you have to notice before we start:

• I’m going to inherit from WContainerWidget. As you now know, I could have inherited from WApplication too.
• Most controls like, WLabel, WLineEdit and WPushButton include a “parent” parameter in their constructors. But you can also create them and add them later to any WContainerWidget. I’m doing this to our text control. To add it to a container you have to call the WContainerWidget::addWidget method.
• The code is based on our previous Hello World application. There are few lines that changed.

So, here it is:

#include <Wt/WApplication>
#include <Wt/WContainerwidget>
#include <Wt/WLabel>
#include <Wt/WLineEdit>
#include <Wt/WPushButton>
#include <Wt/WText>

using namespace Wt;

class FormExample: public WContainerWidget {
private:
    WLabel* label;
    WLineEdit* edit;
    WPushButton* button;
    WText* text;
public:
    FormExample(WContainerWidget *parent = 0): WContainerWidget(parent) {
        label = new WLabel(this);
        edit = new WLineEdit(this);
        button = new WPushButton(this);
        text = new WText();
        addWidget(text);

        label->setText("What is your name? ");
        button->setText("Send");
        button->clicked().connect(this, &FormExample::buttonClicked);
    }

    void buttonClicked() {
        text->setText("Hello " + edit->text());
    }
};

WApplication* createApplication(const WEnvironment &env) {
    WApplication* app = new WApplication(env);
    app->setTitle("Form Test");
    app->root()->addWidget(new FormExample());

    return app;
}

int main(int argc, char** argv) {
    return WRun(argc, argv, &createApplication);
}

You should see something like this:

Happy coding.