Qute - get rid of VariantTemplate and unify func. of injected templates

docs/src/main/asciidoc/qute-reference.adoc

@@ -624,7 +624,7 @@ If you want to use Qute in your Quarkus application add the following dependency
 </dependency>
 ----
 
-In Quarkus, a preconfigured engine instance is provided and available for injection - a bean with scope `@Singleton`, bean type `io.quarkus.qute.Engine` and qualifier `@Default` is registered automatically.
+In Quarkus, a preconfigured engine instance is provided and available for injection - a bean with scope `@ApplicationScoped`, bean type `io.quarkus.qute.Engine` and qualifier `@Default` is registered automatically.
 Moreover, all templates located in the `src/main/resources/templates` directory are validated and can be easily injected. 
 
 [source,java]
@@ -649,6 +649,29 @@ class MyBean {
 <2> The `ResourcePath` qualifier instructs the container to inject a template from a path relative from `src/main/resources/templates`. In this case, the full path is `src/main/resources/templates/detail/items2_v1.html`. 
 <3> Inject the configured `Engine` instance.
 
+=== Template Variants
+
+Sometimes it's useful to render a specific variant of the template based on the content negotiation.
+This can be done by setting a special attribute via `TemplateInstance.setAttribute()`:
+
+[source,java]
+----
+class MyService {
+
+    @Inject
+    Template items; <1>
+
+    @Inject
+    ItemManager manager;
+
+    String renderItems() {
+       return items.data("items",manager.findItems()).setAttribute(TemplateInstance.SELECTED_VARIANT, new Variant(Locale.getDefault(),"text/html","UTF-8")).render();
+    }
+}
+----
+
+NOTE: When using `quarkus-resteasy-qute` the content negotiation is performed automatically. See <<resteasy_integration>>.
+
 === Injecting Beans Directly In Templates
 
 A CDI bean annotated with `@Named` can be referenced in any template through the `inject` namespace:
@@ -885,6 +908,7 @@ class Item {
 ----
 <1> The generated value resolver knows how to invoke the `BigDecimal.setScale()` method.
 
+[[resteasy_integration]]
 === RESTEasy Integration
 
 If you want to use Qute in your JAX-RS application, you'll need to add the `quarkus-resteasy-qute` extension first.
@@ -931,18 +955,17 @@ public class HelloResource {
 <2> `Template.data()` returns a new template instance that can be customized before the actual rendering is triggered. In this case, we put the name value under the key `name`. The data map is accessible during rendering. 
 <3> Note that we don't trigger the rendering - this is done automatically by a special `ContainerResponseFilter` implementation.
 
-==== Variant Templates
 
-Sometimes it could be useful to render a specific variant of the template based on the content negotiation.
-`VariantTemplate` is a perfect match for this use case:
+The content negotiation is performed automatically.
+The resulting output depends on the `Accept` header received from the client.
 
 [source,java]
 ----
 @Path("/detail")
 class DetailResource {
 
     @Inject
-    VariantTemplate item; <1>
+    Template item; <1>
 
     @GET
     @Produces({ MediaType.TEXT_HTML, MediaType.TEXT_PLAIN })
@@ -952,7 +975,7 @@ class DetailResource {
 }
 ----
 <1> Inject a variant template with base path derived from the injected field - `src/main/resources/templates/item`.
-<2> The resulting output depends on the `Accept` header received from the client. For `text/plain` the `src/main/resources/templates/item.txt` template is used. For `text/html` the `META-INF/resources/templates/item.html` template is used.
+<2> For `text/plain` the `src/main/resources/templates/item.txt` template is used. For `text/html` the `META-INF/resources/templates/item.html` template is used.
 
 
 === Development Mode

extensions/mailer/runtime/src/main/java/io/quarkus/mailer/runtime/MailTemplateInstanceImpl.java

@@ -1,8 +1,5 @@
 package io.quarkus.mailer.runtime;
 
-import static io.quarkus.qute.api.VariantTemplate.SELECTED_VARIANT;
-import static io.quarkus.qute.api.VariantTemplate.VARIANTS;
-
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
@@ -16,7 +13,6 @@
 import io.quarkus.mailer.MailTemplate.MailTemplateInstance;
 import io.quarkus.qute.TemplateInstance;
 import io.quarkus.qute.Variant;
-import io.quarkus.qute.api.VariantTemplate;
 import io.smallrye.mutiny.Uni;
 
 class MailTemplateInstanceImpl implements MailTemplate.MailTemplateInstance {
@@ -89,24 +85,22 @@ public MailTemplateInstance data(String key, Object value) {
 
     @Override
     public CompletionStage<Void> send() {
-        if (templateInstance.getAttribute(VariantTemplate.VARIANTS) != null) {
-
+        Object variantsAttr = templateInstance.getAttribute(TemplateInstance.VARIANTS);
+        if (variantsAttr != null) {
             List<Result> results = new ArrayList<>();
-
             @SuppressWarnings("unchecked")
-            List<Variant> variants = (List<Variant>) templateInstance.getAttribute(VARIANTS);
+            List<Variant> variants = (List<Variant>) variantsAttr;
             for (Variant variant : variants) {
                 if (variant.mediaType.equals(Variant.TEXT_HTML) || variant.mediaType.equals(Variant.TEXT_PLAIN)) {
                     results.add(new Result(variant,
                             Uni.createFrom().completionStage(
-                                    () -> templateInstance.setAttribute(SELECTED_VARIANT, variant).data(data).renderAsync())));
+                                    () -> templateInstance.setAttribute(TemplateInstance.SELECTED_VARIANT, variant).data(data)
+                                            .renderAsync())));
                 }
             }
-
             if (results.isEmpty()) {
                 throw new IllegalStateException("No suitable template variant found");
             }
-
             List<Uni<String>> unis = results.stream().map(Result::getValue).collect(Collectors.toList());
             return Uni.combine().all().unis(unis)
                     .combinedWith(combine(results))

extensions/mailer/runtime/src/main/java/io/quarkus/mailer/runtime/MailTemplateProducer.java

@@ -14,8 +14,8 @@
 import org.jboss.logging.Logger;
 
 import io.quarkus.mailer.MailTemplate;
+import io.quarkus.qute.Template;
 import io.quarkus.qute.api.ResourcePath;
-import io.quarkus.qute.api.VariantTemplate;
 
 @Singleton
 public class MailTemplateProducer {
@@ -26,7 +26,7 @@ public class MailTemplateProducer {
     MutinyMailerImpl mailer;
 
     @Any
-    Instance<VariantTemplate> template;
+    Instance<Template> template;
 
     @Produces
     MailTemplate getDefault(InjectionPoint injectionPoint) {

extensions/qute/deployment/src/main/java/io/quarkus/qute/deployment/QuteProcessor.java

@@ -86,7 +86,6 @@
 import io.quarkus.qute.UserTagSectionHelper;
 import io.quarkus.qute.Variant;
 import io.quarkus.qute.api.ResourcePath;
-import io.quarkus.qute.api.VariantTemplate;
 import io.quarkus.qute.deployment.TemplatesAnalysisBuildItem.TemplateAnalysis;
 import io.quarkus.qute.deployment.TypeCheckExcludeBuildItem.Check;
 import io.quarkus.qute.deployment.TypeInfos.Info;
@@ -98,7 +97,6 @@
 import io.quarkus.qute.runtime.QuteRecorder;
 import io.quarkus.qute.runtime.QuteRecorder.QuteContext;
 import io.quarkus.qute.runtime.TemplateProducer;
-import io.quarkus.qute.runtime.VariantTemplateProducer;
 import io.quarkus.qute.runtime.extensions.CollectionTemplateExtensions;
 import io.quarkus.qute.runtime.extensions.MapTemplateExtensions;
 import io.quarkus.qute.runtime.extensions.NumberTemplateExtensions;
@@ -108,11 +106,8 @@ public class QuteProcessor {
     private static final Logger LOGGER = Logger.getLogger(QuteProcessor.class);
 
     public static final DotName RESOURCE_PATH = DotName.createSimple(ResourcePath.class.getName());
-
     public static final DotName TEMPLATE = DotName.createSimple(Template.class.getName());
 
-    public static final DotName VARIANT_TEMPLATE = DotName.createSimple(VariantTemplate.class.getName());
-
     static final DotName ITERABLE = DotName.createSimple(Iterable.class.getName());
     static final DotName ITERATOR = DotName.createSimple(Iterator.class.getName());
     static final DotName STREAM = DotName.createSimple(Stream.class.getName());
@@ -164,7 +159,7 @@ void processTemplateErrors(TemplatesAnalysisBuildItem analysis, List<IncorrectEx
     AdditionalBeanBuildItem additionalBeans() {
         return AdditionalBeanBuildItem.builder()
                 .setUnremovable()
-                .addBeanClasses(EngineProducer.class, TemplateProducer.class, VariantTemplateProducer.class, ResourcePath.class,
+                .addBeanClasses(EngineProducer.class, TemplateProducer.class, ResourcePath.class,
                         Template.class, TemplateInstance.class, CollectionTemplateExtensions.class,
                         MapTemplateExtensions.class, NumberTemplateExtensions.class)
                 .build();
@@ -682,24 +677,6 @@ void validateTemplateInjectionPoints(QuteConfig config, List<TemplatePathBuildIt
                                 new IllegalStateException("No template found for " + injectionPoint.getTargetInfo())));
                     }
                 }
-
-            } else if (injectionPoint.getRequiredType().name().equals(VARIANT_TEMPLATE)) {
-
-                AnnotationInstance resourcePath = injectionPoint.getRequiredQualifier(RESOURCE_PATH);
-                String name;
-                if (resourcePath != null) {
-                    name = resourcePath.value().asString();
-                } else if (injectionPoint.hasDefaultedQualifier()) {
-                    name = getName(injectionPoint);
-                } else {
-                    name = null;
-                }
-                if (name != null) {
-                    if (filePaths.stream().noneMatch(path -> path.endsWith(name))) {
-                        validationErrors.produce(new ValidationErrorBuildItem(
-                                new IllegalStateException("No variant template found for " + injectionPoint.getTargetInfo())));
-                    }
-                }
             }
         }
     }
@@ -721,7 +698,7 @@ TemplateVariantsBuildItem collectTemplateVariants(List<TemplatePathBuildItem> te
                 variants.add(path);
             }
         }
-        LOGGER.debugf("Variant templates found: %s", baseToVariants);
+        LOGGER.debugf("Template variants found: %s", baseToVariants);
         return new TemplateVariantsBuildItem(baseToVariants);
     }
 

extensions/qute/deployment/src/test/java/io/quarkus/qute/deployment/VariantTemplateTest.java

@@ -11,9 +11,9 @@
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.RegisterExtension;
 
+import io.quarkus.qute.Template;
 import io.quarkus.qute.TemplateInstance;
 import io.quarkus.qute.Variant;
-import io.quarkus.qute.api.VariantTemplate;
 import io.quarkus.test.QuarkusUnitTest;
 
 public class VariantTemplateTest {
@@ -31,17 +31,17 @@ public class VariantTemplateTest {
     @Test
     public void testRendering() {
         TemplateInstance rendering = simpleBean.foo.instance().data("bar");
-        rendering.setAttribute(VariantTemplate.SELECTED_VARIANT, new Variant(null, "text/plain", null));
+        rendering.setAttribute(TemplateInstance.SELECTED_VARIANT, new Variant(null, "text/plain", null));
         assertEquals("bar", rendering.render());
-        rendering.setAttribute(VariantTemplate.SELECTED_VARIANT, new Variant(null, "text/html", null));
+        rendering.setAttribute(TemplateInstance.SELECTED_VARIANT, new Variant(null, "text/html", null));
         assertEquals("<strong>bar</strong>", rendering.render());
     }
 
     @Dependent
     public static class SimpleBean {
 
         @Inject
-        VariantTemplate foo;
+        Template foo;
 
     }
 

extensions/qute/runtime/src/main/java/io/quarkus/qute/runtime/EngineProducer.java

@@ -192,7 +192,7 @@ static Variant guessVariant(String path) {
         int suffixIdx = path.lastIndexOf('.');
         if (suffixIdx != -1) {
             String suffix = path.substring(suffixIdx);
-            return new Variant(null, VariantTemplateProducer.parseMediaType(suffix), null);
+            return new Variant(null, TemplateProducer.parseMediaType(suffix), null);
         }
         return null;
     }