com.github.jknack.handlebars.Handlebars Java Examples

@Override
public Object eval(String script, ScriptContext context) throws ScriptException {
    final Resource resource = (Resource) context.getBindings(ScriptContext.ENGINE_SCOPE).get(SlingBindings.RESOURCE);
    final PrintWriter out = (PrintWriter) context.getBindings(ScriptContext.ENGINE_SCOPE).get(SlingBindings.OUT);

    try {
        final Handlebars handlebars = setupHandlebars();
        final Template template = handlebars.compileInline(script);
        out.println(template.apply(getData(resource)));
    } catch(IOException ioe) {
        final ScriptException up = new ScriptException("IOException in eval");
        up.initCause(ioe);
        throw up;
    }
    return null;
}
 

private void writeTestsPassedReport() throws IOException {
    Template template = new Helpers(new Handlebars()).registerHelpers().compile(TEST_OVERVIEW_REPORT);

    List<TestSuiteModel> onlyPassed = new ArrayList<>(processedTestSuites);

    for (Iterator<TestSuiteModel> it = onlyPassed.listIterator(); it.hasNext(); ) {
        TestSuiteModel f = it.next();
        if (f.getOverallStatus().equalsIgnoreCase(Constants.FAILED)) {
            it.remove();
        }
    }

    AllRSpecJUnitReports allTestSuites = new AllRSpecJUnitReports("Passed test suites report", onlyPassed);
    FileUtils.writeStringToFile(new File(TEST_OVERVIEW_PATH + "testsPassed.html"),
        template.apply(allTestSuites));
}
 

static Handlebars create(final List<TemplateLoader> templateLoaders, final I18nResolver i18NResolver, final I18nIdentifierFactory i18nIdentifierFactory) {
    if (templateLoaders.isEmpty()) {
        throw new SunriseConfigurationException("Could not initialize Handlebars due to missing template loaders configuration", CONFIG_TEMPLATE_LOADERS);
    }
    logger.info("Provide Handlebars: template loaders [{}]]",
            templateLoaders.stream().map(TemplateLoader::getPrefix).collect(joining(", ")));
    final TemplateLoader[] loaders = templateLoaders.toArray(new TemplateLoader[templateLoaders.size()]);
    final Handlebars handlebars = new Handlebars()
            .with(loaders)
            .with(new HighConcurrencyTemplateCache())
            .infiniteLoops(true);
    handlebars.registerHelper("i18n", new HandlebarsI18nHelper(i18NResolver, i18nIdentifierFactory));
    handlebars.registerHelper("cms", new HandlebarsCmsHelper());
    handlebars.registerHelper("json", new HandlebarsJsonHelper<>());
    return handlebars;
}
 

/**
 * Compile given template.
 *
 * @param defaultTemplateDir template directory
 * @param templateName template name
 * @return Generated template
 * @throws IOException if file read went wrong
 */
public static Template compileTemplate(String defaultTemplateDir, String templateName) throws IOException {
    String templatesDirPath = System.getProperty(GeneratorConstants.TEMPLATES_DIR_PATH_KEY, defaultTemplateDir);
    ClassPathTemplateLoader cpTemplateLoader = new ClassPathTemplateLoader((templatesDirPath));
    FileTemplateLoader fileTemplateLoader = new FileTemplateLoader(templatesDirPath);
    cpTemplateLoader.setSuffix(GeneratorConstants.TEMPLATES_SUFFIX);
    fileTemplateLoader.setSuffix(GeneratorConstants.TEMPLATES_SUFFIX);

    Handlebars handlebars = new Handlebars().with(cpTemplateLoader, fileTemplateLoader);
    handlebars.setStringParams(true);
    handlebars.registerHelpers(StringHelpers.class);
    handlebars.registerHelper("equals", (object, options) -> {
        Object param0 = options.param(0, null);

        if (param0 == null) {
            throw new IllegalArgumentException("found 'null', expected 'string'");
        }
        if (object != null && object.toString().equals(param0.toString())) {
                return options.fn(options.context);
        }

        return options.inverse();
    });

    return handlebars.compile(templateName);
}
 

@Provides
@Singleton
public Handlebars providesHandlebars() {
  SingularityRunnerBaseLogging.quietEagerLogging(); // handlebars emits DEBUG logs before logger is properly configured
  final Handlebars handlebars = new Handlebars();

  handlebars.registerHelper(BashEscapedHelper.NAME, new BashEscapedHelper());
  handlebars.registerHelper(ShellQuoteHelper.NAME, new ShellQuoteHelper());
  handlebars.registerHelper(IfPresentHelper.NAME, new IfPresentHelper());
  handlebars.registerHelper(
    IfHasNewLinesOrBackticksHelper.NAME,
    new IfHasNewLinesOrBackticksHelper()
  );
  handlebars.registerHelper(
    EscapeNewLinesAndQuotesHelper.NAME,
    new EscapeNewLinesAndQuotesHelper()
  );

  return handlebars;
}
 

@Test
public void whenBlockIsDefined_ThenCanOverrideWithPartial() throws IOException {
    Handlebars handlebars = new Handlebars(templateLoader);
    Template template = handlebars.compile("simplemessage");
    Person person = new Person();
    person.setName("Baeldung");

    String templateString = template.apply(person);

    assertThat(templateString).contains("<html>",
      "<body>",
      "This is the intro",
      "Hi there!",
      "</body>",
      "</html>");
}
 

private String getBannersFooter(Handlebars handlebars, Map<String, Object> context) {
    try {
        Template template = handlebars.compile("templates/banner_footer");

        context.put("bannerJSON", getActiveBannersJSON());

        return template.apply(context);
    } catch (IOException e) {
        log.warn("IOException while getting banners footer", e);
        return "";
    }
}
 

@Provides
@Singleton
@Named(LOGROTATE_CRON_TEMPLATE)
public Template providesLogrotateCronTemplate(Handlebars handlebars)
  throws IOException {
  return handlebars.compile(LOGROTATE_CRON_TEMPLATE);
}
 

@Provides
@Singleton
@Named(LOGROTATE_HOURLY_TEMPLATE)
public Template providesLogrotateHourlyTemplate(Handlebars handlebars)
  throws IOException {
  return handlebars.compile(LOGROTATE_HOURLY_TEMPLATE);
}
 

public static Template template(String templateName) {
	try {
		Handlebars handlebars = new Handlebars(
				new ClassPathTemplateLoader("/templates/spring-cloud/"));
		handlebars.registerHelper("replace", StringHelpers.replace);
		handlebars.registerHelper("capitalizeFirst", StringHelpers.capitalizeFirst);
		return handlebars.compile(templateName);
	}
	catch (IOException e) {
		throw new IllegalStateException(e);
	}
}
 

private String getTimezoneCheckFooter(Handlebars handlebars, Map<String, Object> context) {
    if (ServerConfigurationService.getBoolean("pasystem.timezone-check", true)) {

        try {
            Template template = handlebars.compile("templates/timezone_footer");

            return template.apply(context);
        } catch (IOException e) {
            log.warn("Timezone footer failed", e);
            return "";
        }
    } else {
        return "";
    }
}
 

private String getPopupsFooter(Handlebars handlebars, Map<String, Object> context) {
    Session session = SessionManager.getCurrentSession();
    User currentUser = UserDirectoryService.getCurrentUser();

    if (currentUser == null || currentUser.getId() == null || "".equals(currentUser.getId())) {
        return "";
    }

    try {
        if (session.getAttribute(POPUP_SCREEN_SHOWN) == null) {
            Popup popup = new PopupForUser(currentUser).getPopup();
            if (popup.isActiveNow()) {
                context.put("popupTemplate", popup.getTemplate());
                context.put("popupUuid", popup.getUuid());
                context.put("popup", true);

                if (currentUser.getId() != null) {
                    // Delivered!
                    session.setAttribute(POPUP_SCREEN_SHOWN, "true");
                }
            }
        }


        Template template = handlebars.compile("templates/popup_footer");
        return template.apply(context);
    } catch (IOException | MissingUuidException e) {
        log.warn("IOException while getting popups footer", e);
        return "";
    }
}
 

@Test
public void whenThereIsNoTemplateFile_ThenCompilesInline() throws IOException {
    Handlebars handlebars = new Handlebars();
    Template template = handlebars.compileInline("Hi {{this}}!");

    String templateString = template.apply("Baeldung");

    assertThat(templateString).isEqualTo("Hi Baeldung!");
}
 

private Handlebars loadHandleBars(final I18n i18n) {
    Handlebars handlebars = new Handlebars()
            .with(cache);

    handlebars.registerHelper("t", new Helper<Object>() {
        @Override
        public CharSequence apply(final Object context, final Options options) {
            String key = options.param(0);
            return i18n.t(key);
        }
    });

    return handlebars;
}
 

public Xsd2JaxbGenerator() {
    Handlebars handlebars = new Handlebars();
    handlebars.registerHelper("capFirst", StringHelpers.capitalize);
    handlebars.registerHelper("each",
            new com.legstar.jaxb.generator.EachHelper());
    hbtJaxbWrapperFactoryClass = loadTemplate(handlebars,
            JAXB_WRAPPER_FACTORY_CLASS_TEMPLATE_NAME);
    hbtJaxbConverterClass = loadTemplate(handlebars,
            JAXB_CONVERTER_CLASS_TEMPLATE_NAME);
    modelBuilder = new Xsd2CobolTypesModelBuilder();
}
 

private Template loadTemplate(Handlebars handlebars, String resourceName) {
    try {
        String text = IOUtils.toString(getClass().getResourceAsStream(
                resourceName));
        return handlebars.compileInline(text);
    } catch (IOException e) {
        throw new Xsd2ConverterException(e);
    }
}
 

public Xsd2CobolTypesGenerator() {
    try {
        String text = IOUtils.toString(getClass().getResourceAsStream(
                JAVA_CLASS_TEMPLATE_NAME));
        Handlebars handlebars = new Handlebars();
        hbtJavaClass = handlebars.compileInline(text);
        modelBuilder = new Xsd2CobolTypesModelBuilder();
    } catch (IOException e) {
        throw new Xsd2ConverterException(e);
    }
}
 

private static void testTemplate(final String templateName, final Locale locale, final Map<String, String> i18nMap,
                                 final Consumer<String> test) {
    final Handlebars handlebars = HandlebarsFactory.create(singletonList(DEFAULT_LOADER), i18nResolver(i18nMap), new I18nIdentifierFactory());
    final TemplateEngine templateEngine = HandlebarsTemplateEngine.of(handlebars, new HandlebarsContextFactory(new PlayJavaFormResolver(msg -> msg)));
    final String html = renderTemplate(templateName, templateEngine, locale);
    test.accept(html);
}
 

@Override
public String getFooter() {
    StringBuilder result = new StringBuilder();

    I18n i18n = getI18n(this.getClass().getClassLoader(), "org.sakaiproject.pasystem.impl.i18n.pasystem");
    Handlebars handlebars = loadHandleBars(i18n);

    Session session = SessionManager.getCurrentSession();

    Map<String, Object> context = new HashMap<String, Object>();

    try {
        Template template = handlebars.compile("templates/shared_footer");

        context.put("portalCDNQuery", PortalUtils.getCDNQuery());
        context.put("sakai_csrf_token", session.getAttribute("sakai.csrf.token"));

        result.append(template.apply(context));
    } catch (IOException e) {
        log.warn("IOException while getting footer", e);
        return "";
    }

    result.append(getBannersFooter(handlebars, context));
    result.append(getPopupsFooter(handlebars, context));
    result.append(getTimezoneCheckFooter(handlebars, context));

    return result.toString();
}
 

private void writeTestCaseSummaryReport() throws IOException {
    Template template = new Helpers(new Handlebars()).registerHelpers().compile(TEST_SUMMARY_REPORT);
    for (TestSuiteModel ts : processedTestSuites) {
        String content = template.apply(ts);
        FileUtils.writeStringToFile(new File(TEST_SUMMARY_PATH + ts.getUniqueID() + ".html"),
            content);
    }
}
 

/**
 * Constructs a handlebars template engine
 *
 * @param resourceRoot the resource root
 */
public HandlebarsTemplateEngine(String resourceRoot) {
    TemplateLoader templateLoader = new ClassPathTemplateLoader();
    templateLoader.setPrefix(resourceRoot);
    templateLoader.setSuffix(null);

    handlebars = new Handlebars(templateLoader);

    // Set Guava cache.
    Cache<TemplateSource, Template> cache = CacheBuilder.newBuilder().expireAfterWrite(10, TimeUnit.MINUTES)
            .maximumSize(1000).build();

    handlebars = handlebars.with(new GuavaTemplateCache(cache));
}
 

@Test
public void whenUsedWith_ThenContextChanges() throws IOException {
    Handlebars handlebars = new Handlebars(templateLoader);
    Template template = handlebars.compile("with");
    Person person = getPerson("Baeldung");
    person.getAddress().setStreet("World");

    String templateString = template.apply(person);

    assertThat(templateString).contains("<h4>I live in World</h4>");
}
 

private String getPopupsFooter(Handlebars handlebars, Map<String, Object> context) {
    Session session = SessionManager.getCurrentSession();
    User currentUser = UserDirectoryService.getCurrentUser();

    if (currentUser == null || currentUser.getId() == null || "".equals(currentUser.getId())) {
        return "";
    }

    try {
        if (session.getAttribute(POPUP_SCREEN_SHOWN) == null) {
            Popup popup = new PopupForUser(currentUser).getPopup();
            if (popup.isActiveNow()) {
                context.put("popupTemplate", popup.getTemplate());
                context.put("popupUuid", popup.getUuid());
                context.put("popup", true);

                if (currentUser.getId() != null) {
                    // Delivered!
                    session.setAttribute(POPUP_SCREEN_SHOWN, "true");
                }
            }
        }


        Template template = handlebars.compile("templates/popup_footer");
        return template.apply(context);
    } catch (IOException | MissingUuidException e) {
        log.warn("IOException while getting popups footer", e);
        return "";
    }
}
 

private String getBannersFooter(Handlebars handlebars, Map<String, Object> context) {
    try {
        Template template = handlebars.compile("templates/banner_footer");

        context.put("bannerJSON", getActiveBannersJSON());

        return template.apply(context);
    } catch (IOException e) {
        log.warn("IOException while getting banners footer", e);
        return "";
    }
}
 

private Handlebars loadHandleBars(final I18n i18n) {
    Handlebars handlebars = new Handlebars()
            .with(cache);

    handlebars.registerHelper("t", new Helper<Object>() {
        @Override
        public CharSequence apply(final Object context, final Options options) {
            String key = options.param(0);
            return i18n.t(key);
        }
    });

    return handlebars;
}
 

@Override
public String getFooter() {
    StringBuilder result = new StringBuilder();

    I18n i18n = getI18n(this.getClass().getClassLoader(), "org.sakaiproject.pasystem.impl.i18n.pasystem");
    Handlebars handlebars = loadHandleBars(i18n);

    Session session = SessionManager.getCurrentSession();

    Map<String, Object> context = new HashMap<String, Object>();

    try {
        Template template = handlebars.compile("templates/shared_footer");

        context.put("portalCDNQuery", PortalUtils.getCDNQuery());
        context.put("sakai_csrf_token", session.getAttribute("sakai.csrf.token"));

        result.append(template.apply(context));
    } catch (IOException e) {
        log.warn("IOException while getting footer", e);
        return "";
    }

    result.append(getBannersFooter(handlebars, context));
    result.append(getPopupsFooter(handlebars, context));
    result.append(getTimezoneCheckFooter(handlebars, context));

    return result.toString();
}
 

@Override
public void addHandlebarHelpers(Handlebars handlebars) {
    super.addHandlebarHelpers(handlebars);
    handlebars.registerHelper("multiplelines", getMultipleLinesHelper());
    handlebars.registerHelper("getClassNameFromImports",
            getClassNameFromImportsHelper());
    handlebars.registerHelper("getModelType", getModelTypeHelper());
    handlebars.registerHelper("getModelConstructor",
            getModelConstructorHelper());
}
 

public TemplateEngine(String template) {
    SimpleFilterProvider simpleFilterProvider = new SimpleFilterProvider();
    simpleFilterProvider.setFailOnUnknownId(false);
    ObjectMapper objectMapper = new ObjectMapper();
    objectMapper.setFilters(simpleFilterProvider);

    handlebars = new Handlebars(new ClassPathTemplateLoader("/", ""));
    handlebars.registerHelper("json", new Jackson2Helper(objectMapper));
    handlebars.registerHelper("join", StringHelpers.join);
    handlebars.registerHelper("ifequal", IfEqualHelper.INSTANCE);
    handlebars.prettyPrint(true);

    location = "templates/" + template;
}
 

@Test
public void whenUsedIf_ThenPutsCondition() throws IOException {
    Handlebars handlebars = new Handlebars(templateLoader);
    Template template = handlebars.compile("if");
    Person person = getPerson("Baeldung");
    person.setBusy(true);

    String templateString = template.apply(person);

    assertThat(templateString).contains("<h4>Baeldung is busy.</h4>");
}
 

public Templater() {
	templates.put(MSG_KEY_THING + "-apns", TEMPLATE_THING);
	templates.put(MSG_KEY_ENUM + "-apns", TEMPLATE_ENUM);
	handlebars = new Handlebars()
		.registerHelper(EnumHelper.NAME, EnumHelper.INSTANCE)
		.registerHelpers(HandlebarsHelpersSource.class)
		.registerHelpers(StringHelpers.class);
}