Make sure the empty callback is only called during rendering

Author: jeffgbutler

src/main/java/org/mybatis/dynamic/sql/AbstractListValueCondition.java

@@ -41,12 +41,12 @@ public final <R> Stream<R> mapValues(Function<T, R> mapper) {
 
     @Override
     public boolean shouldRender() {
-        if (values.isEmpty()) {
-            emptyCallback.call();
-            return false;
-        } else {
-            return true;
-        }
+        return !values.isEmpty();
+    }
+
+    @Override
+    public void renderingSkipped() {
+        emptyCallback.call();
     }
 
     @Override

src/main/java/org/mybatis/dynamic/sql/VisitableCondition.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2016-2020 the original author or authors.
+ *    Copyright 2016-2021 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -28,4 +28,10 @@ public interface VisitableCondition<T> {
     default boolean shouldRender() {
         return true;
     }
+
+    /**
+     * This method will be called during rendering when {@link VisitableCondition#shouldRender()}
+     * returns false.
+     */
+    default void renderingSkipped() {}
 }

src/main/java/org/mybatis/dynamic/sql/where/render/CriterionRenderer.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2016-2020 the original author or authors.
+ *    Copyright 2016-2021 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -69,6 +69,7 @@ public <T> Optional<RenderedCriterion> visit(ColumnAndConditionCriterion<T> crit
         if (criterion.condition().shouldRender()) {
             return renderWithInitialCondition(renderCondition(criterion), criterion);
         } else {
+            criterion.condition().renderingSkipped();
             return renderWithoutInitialCondition(criterion);
         }
     }