Implement Callback for In and NotIn Conditions When the Value List is Empty

.github/dependabot.yml

@@ -1,3 +1,19 @@
+#
+#    Copyright 2016-2020 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.
+#    You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS,
+#    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#    See the License for the specific language governing permissions and
+#    limitations under the License.
+#
+
 version: 2
 updates:
 - package-ecosystem: maven

CHANGELOG.md

@@ -2,6 +2,18 @@
 
 This log will detail notable changes to MyBatis Dynamic SQL. Full details are available on the GitHub milestone pages.
 
+## Release 1.2.1 - Unreleased
+
+GitHub milestone: [https://github.com/mybatis/mybatis-dynamic-sql/issues?q=milestone%3A1.2.1+](https://github.com/mybatis/mybatis-dynamic-sql/issues?q=milestone%3A1.2.1+)
+
+### Fixed
+
+- Fixed a bug where the In conditions could render incorrectly in certain circumstances. ([#239](https://github.com/mybatis/mybatis-dynamic-sql/issues/239))
+
+### Added
+
+- Added a callback capability to the "In" conditions that will be called before rendering when the conditions are empty. Also, removed the option that forced the library to render invalid SQL in that case. ([#241](https://github.com/mybatis/mybatis-dynamic-sql/pull/241))
+
 ## Release 1.2.0 - August 19, 2020
 
 GitHub milestone: [https://github.com/mybatis/mybatis-dynamic-sql/issues?q=milestone%3A1.2.0+](https://github.com/mybatis/mybatis-dynamic-sql/issues?q=milestone%3A1.2.0+)
@@ -14,7 +26,7 @@ This release includes a significant refactoring of the classes in the "org.mybat
 
 With this release, we deprecated several insert methods because they were inconsistently named or awkward. All deprecated methods have documented direct replacements.
 
-All deprecated code will be removed in the next release.
+All deprecated code will be removed in the next minor release.
 
 ### Added
 

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

@@ -22,19 +22,26 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
-public abstract class AbstractListValueCondition<T> implements VisitableCondition<T> {
+public abstract class AbstractListValueCondition<T, S extends AbstractListValueCondition<T, S>>
+        implements VisitableCondition<T> {
     protected final Collection<T> values;
     protected final UnaryOperator<Stream<T>> valueStreamTransformer;
-    protected boolean renderWhenEmpty = false;
+    protected final Callback emptyCallback;
 
     protected AbstractListValueCondition(Collection<T> values) {
-        this(values, UnaryOperator.identity());
+        this(values, UnaryOperator.identity(), () -> { });
     }
 
     protected AbstractListValueCondition(Collection<T> values, UnaryOperator<Stream<T>> valueStreamTransformer) {
+        this(values, valueStreamTransformer, () -> { });
+    }
+
+    protected AbstractListValueCondition(Collection<T> values, UnaryOperator<Stream<T>> valueStreamTransformer,
+            Callback emptyCallback) {
         this.valueStreamTransformer = Objects.requireNonNull(valueStreamTransformer);
         this.values = valueStreamTransformer.apply(Objects.requireNonNull(values).stream())
             .collect(Collectors.toList());
+        this.emptyCallback = Objects.requireNonNull(emptyCallback);
     }
 
     public final <R> Stream<R> mapValues(Function<T, R> mapper) {
@@ -43,20 +50,20 @@ public final <R> Stream<R> mapValues(Function<T, R> mapper) {
 
     @Override
     public boolean shouldRender() {
-        return !values.isEmpty() || renderWhenEmpty;
+        if (values.isEmpty()) {
+            emptyCallback.call();
+            return false;
+        } else {
+            return true;
+        }
     }
 
-    /**
-     * Use with caution - this could cause the library to render invalid SQL like "where column in ()".
-     */
-    protected void forceRenderingWhenEmpty() {
-        renderWhenEmpty = true;
-    }
-
     @Override
     public <R> R accept(ConditionVisitor<T, R> visitor) {
         return visitor.visit(this);
     }
 
+    public abstract S withListEmptyCallback(Callback callback);
+
     public abstract String renderCondition(String columnName, Stream<String> placeholders);
 }

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

@@ -0,0 +1,34 @@
+/**
+ *    Copyright 2016-2020 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.
+ *    You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+package org.mybatis.dynamic.sql;
+
+import java.util.function.Function;
+
+@FunctionalInterface
+public interface Callback {
+    void call();
+
+    static Callback exceptionThrowingCallback(String message) {
+        return exceptionThrowingCallback(message, RuntimeException::new);
+    }
+
+    static Callback exceptionThrowingCallback(String message,
+            Function<String, ? extends RuntimeException> exceptionBuilder) {
+        return () -> {
+            throw exceptionBuilder.apply(message);
+        };
+    }
+}

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

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2016-2018 the original author or authors.
+ *    Copyright 2016-2020 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.
@@ -16,7 +16,7 @@
 package org.mybatis.dynamic.sql;
 
 public interface ConditionVisitor<T, R> {
-    R visit(AbstractListValueCondition<T> condition);
+    R visit(AbstractListValueCondition<T, ?> condition);
 
     R visit(AbstractNoValueCondition<T> condition);
 

src/main/java/org/mybatis/dynamic/sql/util/StringUtilities.java

@@ -16,8 +16,6 @@
 package org.mybatis.dynamic.sql.util;
 
 import java.util.Optional;
-import java.util.function.UnaryOperator;
-import java.util.stream.Stream;
 
 public interface StringUtilities {
 
@@ -42,9 +40,4 @@ static String spaceBefore(String in) {
     static String safelyUpperCase(String s) {
         return s == null ? null : s.toUpperCase();
     }
-
-    static UnaryOperator<Stream<String>> upperCaseAfter(UnaryOperator<Stream<String>> valueModifier) {
-        UnaryOperator<Stream<String>> ua = s -> s.map(StringUtilities::safelyUpperCase);
-        return t -> ua.apply(valueModifier.apply(t));
-    }
 }

src/main/java/org/mybatis/dynamic/sql/where/condition/IsIn.java

@@ -23,15 +23,20 @@
 import java.util.stream.Stream;
 
 import org.mybatis.dynamic.sql.AbstractListValueCondition;
+import org.mybatis.dynamic.sql.Callback;
 
-public class IsIn<T> extends AbstractListValueCondition<T> {
+public class IsIn<T> extends AbstractListValueCondition<T, IsIn<T>> {
+
+    protected IsIn(Collection<T> values) {
+        super(values);
+    }
 
     protected IsIn(Collection<T> values, UnaryOperator<Stream<T>> valueStreamTransformer) {
         super(values, valueStreamTransformer);
     }
 
-    protected IsIn(Collection<T> values) {
-        super(values);
+    protected IsIn(Collection<T> values, UnaryOperator<Stream<T>> valueStreamTransformer, Callback emptyCallback) {
+        super(values, valueStreamTransformer, emptyCallback);
     }
 
     @Override
@@ -40,6 +45,11 @@ public String renderCondition(String columnName, Stream<String> placeholders) {
                 + placeholders.collect(Collectors.joining(",", "in (", ")")); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
     }
 
+    @Override
+    public IsIn<T> withListEmptyCallback(Callback callback) {
+        return new IsIn<>(values, valueStreamTransformer, callback);
+    }
+
     /**
      * This method allows you to modify the condition's values before they are placed into the parameter map.
      * For example, you could filter nulls, or trim strings, etc. This process will run before final rendering of SQL.
@@ -51,9 +61,7 @@ public String renderCondition(String columnName, Stream<String> placeholders) {
      * @return new condition with the specified transformer
      */
     public IsIn<T> then(UnaryOperator<Stream<T>> valueStreamTransformer) {
-        IsIn<T> answer = new IsIn<>(values, valueStreamTransformer);
-        answer.renderWhenEmpty = renderWhenEmpty;
-        return answer;
+        return new IsIn<>(values, valueStreamTransformer, emptyCallback);
     }
 
     public static <T> IsIn<T> of(Collection<T> values) {

src/main/java/org/mybatis/dynamic/sql/where/condition/IsInCaseInsensitive.java

@@ -21,16 +21,22 @@
 import java.util.stream.Stream;
 
 import org.mybatis.dynamic.sql.AbstractListValueCondition;
+import org.mybatis.dynamic.sql.Callback;
 import org.mybatis.dynamic.sql.util.StringUtilities;
 
-public class IsInCaseInsensitive extends AbstractListValueCondition<String> {
+public class IsInCaseInsensitive extends AbstractListValueCondition<String, IsInCaseInsensitive> {
 
     protected IsInCaseInsensitive(Collection<String> values) {
         super(values, s -> s.map(StringUtilities::safelyUpperCase));
     }
 
     protected IsInCaseInsensitive(Collection<String> values, UnaryOperator<Stream<String>> valueStreamTransformer) {
-        super(values, StringUtilities.upperCaseAfter(valueStreamTransformer));
+        super(values, valueStreamTransformer);
+    }
+
+    protected IsInCaseInsensitive(Collection<String> values, UnaryOperator<Stream<String>> valueStreamTransformer,
+            Callback emptyCallback) {
+        super(values, valueStreamTransformer, emptyCallback);
     }
 
     @Override
@@ -39,20 +45,9 @@ public String renderCondition(String columnName, Stream<String> placeholders) {
                 placeholders.collect(Collectors.joining(",", "in (", ")")); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
     }
 
-    /**
-     * This method allows you to modify the condition's values before they are placed into the parameter map.
-     * For example, you could filter nulls, or trim strings, etc. This process will run before final rendering of SQL.
-     * If you filter values out of the stream, then final condition will not reference those values. If you filter all
-     * values out of the stream, then the condition will not render.
-     * 
-     * @param valueStreamTransformer a UnaryOperator that will transform the value stream before
-     *     the values are placed in the parameter map
-     * @return new condition with the specified transformer
-     */
-    public IsInCaseInsensitive then(UnaryOperator<Stream<String>> valueStreamTransformer) {
-        IsInCaseInsensitive answer = new IsInCaseInsensitive(values, valueStreamTransformer);
-        answer.renderWhenEmpty = renderWhenEmpty;
-        return answer;
+    @Override
+    public IsInCaseInsensitive withListEmptyCallback(Callback callback) {
+        return new IsInCaseInsensitive(values, valueStreamTransformer, callback);
     }
 
     public static IsInCaseInsensitive of(Collection<String> values) {

src/main/java/org/mybatis/dynamic/sql/where/condition/IsInCaseInsensitiveWhenPresent.java

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2016-2019 the original author or authors.
+ *    Copyright 2016-2020 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.
@@ -17,11 +17,25 @@
 
 import java.util.Collection;
 import java.util.Objects;
+import java.util.function.UnaryOperator;
+import java.util.stream.Stream;
+import org.mybatis.dynamic.sql.Callback;
+import org.mybatis.dynamic.sql.util.StringUtilities;
 
 public class IsInCaseInsensitiveWhenPresent extends IsInCaseInsensitive {
 
     protected IsInCaseInsensitiveWhenPresent(Collection<String> values) {
-        super(values, s -> s.filter(Objects::nonNull));
+        super(values, s -> s.filter(Objects::nonNull).map(StringUtilities::safelyUpperCase));
+    }
+
+    protected IsInCaseInsensitiveWhenPresent(Collection<String> values,
+            UnaryOperator<Stream<String>> valueStreamTransformer, Callback callback) {
+        super(values, valueStreamTransformer, callback);
+    }
+
+    @Override
+    public IsInCaseInsensitiveWhenPresent withListEmptyCallback(Callback callback) {
+        return new IsInCaseInsensitiveWhenPresent(values, valueStreamTransformer, callback);
     }
 
     public static IsInCaseInsensitiveWhenPresent of(Collection<String> values) {

src/main/java/org/mybatis/dynamic/sql/where/condition/IsNotIn.java

@@ -23,15 +23,20 @@
 import java.util.stream.Stream;
 
 import org.mybatis.dynamic.sql.AbstractListValueCondition;
+import org.mybatis.dynamic.sql.Callback;
 
-public class IsNotIn<T> extends AbstractListValueCondition<T> {
+public class IsNotIn<T> extends AbstractListValueCondition<T, IsNotIn<T>> {
+
+    protected IsNotIn(Collection<T> values) {
+        super(values);
+    }
 
     protected IsNotIn(Collection<T> values, UnaryOperator<Stream<T>> valueStreamTransformer) {
         super(values, valueStreamTransformer);
     }
 
-    protected IsNotIn(Collection<T> values) {
-        super(values);
+    protected IsNotIn(Collection<T> values, UnaryOperator<Stream<T>> valueStreamTransformer, Callback emptyCallback) {
+        super(values, valueStreamTransformer, emptyCallback);
     }
 
     @Override
@@ -41,6 +46,11 @@ public String renderCondition(String columnName, Stream<String> placeholders) {
                         Collectors.joining(",", "not in (", ")")); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
     }
 
+    @Override
+    public IsNotIn<T> withListEmptyCallback(Callback callback) {
+        return new IsNotIn<>(values, valueStreamTransformer, callback);
+    }
+
     /**
      * This method allows you to modify the condition's values before they are placed into the parameter map.
      * For example, you could filter nulls, or trim strings, etc. This process will run before final rendering of SQL.
@@ -52,9 +62,7 @@ public String renderCondition(String columnName, Stream<String> placeholders) {
      * @return new condition with the specified transformer
      */
     public IsNotIn<T> then(UnaryOperator<Stream<T>> valueStreamTransformer) {
-        IsNotIn<T> answer = new IsNotIn<>(values, valueStreamTransformer);
-        answer.renderWhenEmpty = renderWhenEmpty;
-        return answer;
+        return new IsNotIn<>(values, valueStreamTransformer, emptyCallback);
     }
 
     public static <T> IsNotIn<T> of(Collection<T> values) {