The qsTr method does not work on component scripts.

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE TS>
<TS version="2.1" language="ru_RU">
<context>
    <name>Page</name>
    <message>
        <source>Translations Example</source>
        <translation>Пример переводов</translation>
    </message>
    <message>
        <source>This is some text.</source>
        <translation>Это какой то текст</translation>
    </message>
</context>
<context>
    <name>installscript</name>
    <message>
        <source>This is a dynamically created page.</source>
        <translation>Это динамически созданная страница</translation>
    </message>
</context>
</TS>

function Component()
{
    // constructor
    component.loaded.connect(this, Component.prototype.loaded);
    installer.addWizardPage(component, "Page", QInstaller.TargetDirectory)
}

Component.prototype.createOperations = function()
{
    try {
        // call the base create operations function
        component.createOperations();
    } catch (e) {
        console.log(e);
    }
}

Component.prototype.loaded = function ()
{
    var page = gui.pageByObjectName("DynamicPage");
    if (page != null) {
        page.entered.connect(Component.prototype.dynamicPageEntered);
    }
}

Component.prototype.dynamicPageEntered = function ()
{
    var pageWidget = gui.pageWidgetByObjectName("DynamicPage");
    if (pageWidget != null) {
        pageWidget.m_pageLabel.text = qsTr("This is a dynamically created page.");
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<Package>
    <DisplayName>The root component</DisplayName>
    <Description>This component contains a license and translations to German.</Description>
    <Version>0.5.0-1</Version>
    <ReleaseDate>2015-01-29</ReleaseDate>
    <Licenses>
        <License name="Beer Public License Agreement" file="license.txt" />
    </Licenses>
    <Default>true</Default>
    <Script>installscript.qs</Script>
    <UserInterfaces>
        <UserInterface>page.ui</UserInterface>
    </UserInterfaces>
    <Translations>
        <Translation>de.qm</Translation>
        <Translation>pl.qm</Translation>
        <Translation>ru.qm</Translation>
    </Translations>
</Package>