Is there a way to make Spring Thymeleaf handle the string pattern?

Question

I would like to write something like:

@Autowired private SpringTemplateEngine engine; .... // Thymeleaf Context WebContext thymeleafContext = new WebContext(request, response, request.getServletContext(), locale); // cached html of a thymeleaf template file String cachedHtml=.... // process the cached html String html=engine.process(cachedHtml, thymeleafContext); 

By default, the [process] method cannot do this. I can understand from the docs that I need a special template resolver:

To execute the templates, the method (String, IContext) will be used: final String result = templateEngine.process ("mytemplate", ctx); The argument "mytemplate" String is the name of the template, and it will refer to the physical / logical location of the template itself in a way that is configured for resolver / s.

Does anyone know how to solve my problem?

The goal is to cache Thymeleaf templates (files) in lines, and then process abstracts, not files.

Answer 1

You can implement your own TemplateResolver and IResourceResolver to work with String .

Answer 2

The solution we finished consisted of a new IResourceResolver with a custom Context , not a custom TemplateResolver . We chose this because in most cases we still wanted to use class scanning, but sometimes had dynamic content.

The following shows how we did this:

 public class StringAndClassLoaderResourceResolver implements IResourceResolver { public StringAndClassLoaderResourceResolver() { super(); } public String getName() { return getClass().getName().toUpperCase(); } public InputStream getResourceAsStream(final TemplateProcessingParameters params, final String resourceName) { Validate.notNull(resourceName, "Resource name cannot be null"); if( StringContext.class.isAssignableFrom( params.getContext().getClass() ) ){ String content = ((StringContext)params.getContext()).getContent(); return IOUtils.toInputStream(content); } return ClassLoaderUtils.getClassLoader(ClassLoaderResourceResolver.class).getResourceAsStream(resourceName); } public static class StringContext extends Context{ private final String content; public StringContext(String content) { this.content = content; } public StringContext(String content, Locale locale) { super(locale); this.content = content; } public StringContext(String content, Locale locale, Map<String, ?> variables) { super(locale, variables); this.content = content; } public String getContent() { return content; } } 

Test case

 public class StringAndClassLoaderResourceResolverTest { private static SpringTemplateEngine templateEngine; @BeforeClass public static void setup(){ TemplateResolver resolver = new TemplateResolver(); resolver.setResourceResolver(new StringAndClassLoaderResourceResolver()); resolver.setPrefix("mail/"); // src/test/resources/mail resolver.setSuffix(".html"); resolver.setTemplateMode("LEGACYHTML5"); resolver.setCharacterEncoding(CharEncoding.UTF_8); resolver.setOrder(1); templateEngine = new SpringTemplateEngine(); templateEngine.setTemplateResolver(resolver); } @Test public void testStringResolution() { String expected = "<div>dave</div>"; String input = "<div th:text=\"${userName}\">Some Username Here!</div>"; IContext context = new StringAndClassLoaderResourceResolver.StringContext(input); context.getVariables().put("userName", "dave"); String actual = templateEngine.process("redundant", context); assertEquals(expected, actual); } @Test public void testClasspathResolution(){ IContext context = new Context(); context.getVariables().put("message", "Hello Thymeleaf!"); String actual = templateEngine.process("dummy", context); String expected = "<h1>Hello Thymeleaf!</h1>"; assertEquals(expected, actual); } } 

Dummy file template file in src / main / resources / mail / dummy.html

 <h1 th:text="${message}">A message will go here!</h1> 

Note. We used Apache CommonsIO IOUtils to convert String to InputStream

Answer 3

for simple unit tests:

 static class TestResourceResolver implements IResourceResolver { public String content = ""; @Override public String getName() { return "TestTemplateResolver"; } @Override public InputStream getResourceAsStream(TemplateProcessingParameters templateProcessingParameters, String resourceName) { return new ByteArrayInputStream(content.getBytes()); } } 

or just use org.thymeleaf.templateresolver.StringTemplateResolver in Thymeleaf 3

Answer 4

Yep StringTemplateResolver is the way to go.

 public class ReportTemplateEngine { private static TemplateEngine instance; private ReportTemplateEngine(){} public static TemplateEngine getInstance(){ if(instance == null){ synchronized (ReportTemplateEngine.class) { if(instance == null){ instance = new TemplateEngine(); StringTemplateResolver templateResolver = new StringTemplateResolver(); templateResolver.setTemplateMode(TemplateMode.HTML); instance.setTemplateResolver(templateResolver); } } } return instance; } 

}