Producer function can be provided by the LLMConfig to be used fir lazy (

#78)

creation  instead of providing already created bean.

Signed-off-by: Emmanuel Hugonnet <[email protected]>

smallrye-llm-langchain4j-buildcompatible-extension/src/main/java/io/smallrye/llm/plugin/LangChain4JPluginsBuildCompatibleExtension.java

@@ -23,8 +23,9 @@ public class LangChain4JPluginsBuildCompatibleExtension implements BuildCompatib
     @SuppressWarnings({ "unused", "unchecked" })
     @Synthesis
     public void createSynthetics(SyntheticComponents syntheticComponents) throws ClassNotFoundException {
-        if (llmConfig == null)
+        if (llmConfig == null) {
             llmConfig = LLMConfigProvider.getLlmConfig();
+        }
         LOGGER.info("CDI BCE Langchain4j plugin");
 
         /*

smallrye-llm-langchain4j-config-mpconfig/src/main/java/io/smallrye/llm/core/langchain4j/mpconfig/LLMConfigMPConfig.java

@@ -42,7 +42,7 @@ public Set<String> getBeanNames() {
 
     @Override
     public <T> T getBeanPropertyValue(String beanName, String propertyName, Class<T> type) {
-        if (VALUE.equals(propertyName)) {
+        if (PRODUCER.equals(propertyName)) {
             return null;
         }
         T value = config.getOptionalValue(getBeanPropertyName(beanName, propertyName), type).orElse(null);

smallrye-llm-langchain4j-core/src/main/java/io/smallrye/llm/core/langchain4j/core/config/spi/LLMConfig.java

@@ -15,7 +15,7 @@
 public interface LLMConfig {
 
     String PREFIX = "smallrye.llm.plugin";
-    String VALUE = "defined_bean_value";
+    String PRODUCER = "defined_bean_producer";
 
     void init();
 

smallrye-llm-langchain4j-core/src/main/java/io/smallrye/llm/core/langchain4j/core/config/spi/ProducerFunction.java

@@ -0,0 +1,20 @@
+package io.smallrye.llm.core.langchain4j.core.config.spi;
+
+import jakarta.enterprise.inject.Instance;
+
+/**
+ * Simple function to produce synthetics beans via BeanData
+ *
+ * @param <R> the result.
+ */
+@FunctionalInterface
+public interface ProducerFunction<R> {
+    /**
+     * Produces a bean using its name and a lookup context.
+     *
+     * @param lookup: lookup context.
+     * @param beanName: the name of the bean.
+     * @return the created bean.
+     */
+    R produce(Instance<R> lookup, String beanName);
+}

smallrye-llm-langchain4j-core/src/main/java/io/smallrye/llm/plugin/CommonLLMPluginCreator.java

@@ -1,6 +1,6 @@
 package io.smallrye.llm.plugin;
 
-import static io.smallrye.llm.core.langchain4j.core.config.spi.LLMConfig.VALUE;
+import static io.smallrye.llm.core.langchain4j.core.config.spi.LLMConfig.PRODUCER;
 
 import java.lang.annotation.Annotation;
 import java.lang.reflect.InvocationTargetException;
@@ -29,6 +29,7 @@
 import dev.langchain4j.store.embedding.EmbeddingStore;
 import io.smallrye.llm.core.langchain4j.core.config.spi.LLMConfig;
 import io.smallrye.llm.core.langchain4j.core.config.spi.LLMConfigProvider;
+import io.smallrye.llm.core.langchain4j.core.config.spi.ProducerFunction;
 
 /*
 smallrye.llm.plugin.content-retriever.class=dev.langchain4j.rag.content.retriever.EmbeddingStoreContentRetriever
@@ -62,10 +63,12 @@ public static void createAllLLMBeans(LLMConfig llmConfig, Consumer<BeanData> bea
             }
             Class<? extends Annotation> scopeClass = (Class<? extends Annotation>) loadClass(scopeClassName);
             Class<?> targetClass = loadClass(className);
-            Object bean = llmConfig.getBeanPropertyValue(beanName, VALUE, targetClass);
-            if (bean != null) {
+            ProducerFunction<Object> producer = llmConfig.getBeanPropertyValue(beanName, PRODUCER,
+                    ProducerFunction.class);
+            if (producer != null) {
                 beanBuilder.accept(
-                        new BeanData(targetClass, null, scopeClass, beanName, (Instance<Object> creationalContext) -> bean));
+                        new BeanData(targetClass, null, scopeClass, beanName,
+                                (Instance<Object> creationalContext) -> producer.produce(creationalContext, beanName)));
             } else {
                 // test if there is an inner static class Builder
                 Class<?> builderCLass = Arrays.stream(targetClass.getDeclaredClasses())