An extension for Thymeleaf forwarding object-to-string conversions to the appropriate JAX-RS ParamConverter. A possible use for this is to ensure round-trip safety when Thymeleaf writes a parameter (e.g. form field value) that JAX-RS will try to read back.

As the necessary functionality is not standardised, a generic JAX-RS solution is not possible; this module works on Jersey only. Also, this only works with the Standard Dialect - Spring users would probably be content with using the existing Spring converter integration, and have no need for this module.

This extension is a bridge between Jersey and Thymeleaf; it only makes sense to use this if both are already present in your project. No further dependencies are required.

The extension was built using version 2.23.1 of Jersey. As it relies on a non-standardized interface, different versions may or may not work.

The Thymeleaf side is written against the Thymeleaf 3 API. Building a version that works with Thymeleaf 2.1 should be possible, but it is not currently planned. The Conversion Service is a new feature of Thymeleaf 2.1, so earlier versions cannot be supported.

1. Include the library in your project. For example with Maven:

       <dependency>
           <groupId>hu.inbuss</groupId>
           <artifactId>thymeleaf-jersey</artifactId>
           <version>0.0.9</version>
       </dependency>

   or with Gradle:

   dependencies {
       compile 'hu.inbuss:thymeleaf-jersey:0.0.9'
   }

2. Inject a reference to the hu.inbuss.thymeleaf.jaxrs.ParamConverterBridge singleton bean into the class that creates the Thymeleaf TemplateEngine.

3. Either follow the Thymeleaf documentation on custom Conversion Services, i.e.

   import hu.inbuss.thymeleaf.jaxrs.ParamConverterBridge;
   import javax.inject.Inject;
   import org.thymeleaf.TemplateEngine;
   import org.thymeleaf.standard.StandardDialect;
   
   public class ExampleApplication {
       @Inject private ParamConverterBridge pcb;
       private final TemplateEngine engine;
   
       public ExampleApplication() {
           engine = new TemplateEngine();
           final StandardDialect sd = new StandardDialect();
           sd.setConversionService(pcb);
           engine.setDialect(sd);
           /* do other setup */
       }
   }

   or just ask the converter bean to install itself into the Standard Dialect:

   import hu.inbuss.thymeleaf.jaxrs.ParamConverterBridge;
   import javax.inject.Inject;
   import org.thymeleaf.TemplateEngine;
   
   public class ExampleApplication {
       @Inject private ParamConverterBridge pcb;
       private final TemplateEngine engine;
   
       public ExampleApplication() {
           engine = new TemplateEngine();
           pcb.installInto(engine);
           /* do other setup */
       }
   }

4. You're ready. Register ParamConverters for some type yourself or include a library that does so, and use the double-brace syntax when including values of that type in templates. Remember: the Conversion Service only drives double-brace expressions (e.g. ${{user.lastLogin}}). Single-brace ones (${user.lastLogin}) are not affected by this library, and will keep using toString() just like before.