Quit Installer Example

Using a component script to quit an installer.

Quit Installer illustrates how to use the Component() function to display a message box to end users for quitting the installation if some requirements for the installation are not met.

Configuring the Example Installer

The installer configuration file, config.xml, in the config directory specifies the text and default values used in the installer:

  • The <Name> element specifies the application name that is added to the page name and introduction text.
  • The <Version> element specifies the application version number.
  • The <Title> element specifies the installer name displayed on the title bar.
  • The <Publisher> element specifies the publisher of the software (as shown in the Windows Control Panel, for example).
  • The <StartMenuDir> element specifies the name of the default program group for the product in the Windows Start menu.
  • The <TargetDir> element specifies that the default target directory is located in the IfwExamples directory in the home directory of the current user (because the predefined variable@HomeDir@ is used as a part of the value). For more information, see Predefined Variables.
<?xml version="1.0" encoding="UTF-8"?>
    <Name>Quit Installer Example</Name>
    <Title>Quit Installer Example</Title>
    <StartMenuDir>Qt IFW Examples</StartMenuDir>

Creating the Example Package Information File

The installer package information file, package.xml, in the meta directory specifies the components that are available for installation:

  • The <DisplayName> element specifies the human-readable name of the component.
  • The <Description> element specifies the human-readable description of the component.
  • The <Version> element specifies the version number of the component.
  • The <ReleaseDate> element specifies the date when this component version was released.
  • The <Default> element is set to true to preselect the component in the installer.
  • The <Script> element specifies the file name of the JavaScript file that is loaded to perform operations.
<?xml version="1.0"?>
    <DisplayName>Quit an installer</DisplayName>
    <Description>Quits the installer in a nice way, if there is something missing</Description>

Quitting the Installation

In installscript.js, we use the Component() function to display a message box for quitting the installer to end users:

function Component()
    var result = QMessageBox["question"]("test.quit", "Installer", "Do you want to quit the installer?<br>" +
        "This message box was created using JavaScript.", QMessageBox.Ok | QMessageBox.Cancel);

If end users select OK, we use the installer::setValue() function to display a message and the installer.setDefaultPageVisible() function to hide the subsequent installer pages:

    if (result == QMessageBox.Ok) {
        installer.setValue("FinishedText", "<font color='red' size=3>The installer was quit.</font>");
        installer.setDefaultPageVisible(QInstaller.TargetDirectory, false);
        installer.setDefaultPageVisible(QInstaller.ReadyForInstallation, false);
        installer.setDefaultPageVisible(QInstaller.ComponentSelection, false);
        installer.setDefaultPageVisible(QInstaller.StartMenuSelection, false);
        installer.setDefaultPageVisible(QInstaller.PerformInstallation, false);
        installer.setDefaultPageVisible(QInstaller.LicenseCheck, false);

If end users select Cancel, we display the default installer pages and use the installer::setValue() function to display another message on the last installer page:

    } else {
            "<font color='green' size=3>The installer was not quit by JavaScript.</font>");

Generating the Example Installer

To create the example installer, switch to the example source directory on the command line and enter the following command:

  • On Windows:
    ..\..\bin\binarycreator.exe -c config\config.xml -p packages installer.exe
  • On Linux or macOS:
    ../../bin/binarycreator -c config/config.xml -p packages installer

The installer is created in the current directory.


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