Implement filter/map for the between conditions

Author: jeffgbutler

src/main/java/org/mybatis/dynamic/sql/AbstractTwoValueCondition.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.
@@ -16,25 +16,15 @@
 package org.mybatis.dynamic.sql;
 
 import java.util.Objects;
-import java.util.function.BiPredicate;
 import java.util.function.Supplier;
 
 public abstract class AbstractTwoValueCondition<T> implements VisitableCondition<T> {
     protected final Supplier<T> valueSupplier1;
     protected final Supplier<T> valueSupplier2;
-    private final BiPredicate<T, T> predicate;
 
     protected AbstractTwoValueCondition(Supplier<T> valueSupplier1, Supplier<T> valueSupplier2) {
         this.valueSupplier1 = Objects.requireNonNull(valueSupplier1);
         this.valueSupplier2 = Objects.requireNonNull(valueSupplier2);
-        predicate = (v1, v2) -> true;
-    }
-
-    protected AbstractTwoValueCondition(Supplier<T> valueSupplier1, Supplier<T> valueSupplier2,
-            BiPredicate<T, T> predicate) {
-        this.valueSupplier1 = Objects.requireNonNull(valueSupplier1);
-        this.valueSupplier2 = Objects.requireNonNull(valueSupplier2);
-        this.predicate = Objects.requireNonNull(predicate);
     }
 
     public T value1() {
@@ -45,11 +35,6 @@ public T value2() {
         return valueSupplier2.get();
     }
 
-    @Override
-    public boolean shouldRender() {
-        return predicate.test(value1(), value2());
-    }
-
     @Override
     public <R> R accept(ConditionVisitor<T, R> visitor) {
         return visitor.visit(this);

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

@@ -58,7 +58,6 @@
 import org.mybatis.dynamic.sql.util.Buildable;
 import org.mybatis.dynamic.sql.where.WhereDSL;
 import org.mybatis.dynamic.sql.where.condition.IsBetween;
-import org.mybatis.dynamic.sql.where.condition.IsBetweenWhenPresent;
 import org.mybatis.dynamic.sql.where.condition.IsEqualTo;
 import org.mybatis.dynamic.sql.where.condition.IsEqualToColumn;
 import org.mybatis.dynamic.sql.where.condition.IsEqualToWithSubselect;
@@ -80,7 +79,6 @@
 import org.mybatis.dynamic.sql.where.condition.IsLike;
 import org.mybatis.dynamic.sql.where.condition.IsLikeCaseInsensitive;
 import org.mybatis.dynamic.sql.where.condition.IsNotBetween;
-import org.mybatis.dynamic.sql.where.condition.IsNotBetweenWhenPresent;
 import org.mybatis.dynamic.sql.where.condition.IsNotEqualTo;
 import org.mybatis.dynamic.sql.where.condition.IsNotEqualToColumn;
 import org.mybatis.dynamic.sql.where.condition.IsNotEqualToWithSubselect;
@@ -612,12 +610,12 @@ static <T> IsBetween.Builder<T> isBetween(Supplier<T> valueSupplier1) {
         return IsBetween.isBetween(valueSupplier1);
     }
 
-    static <T> IsBetweenWhenPresent.Builder<T> isBetweenWhenPresent(T value1) {
+    static <T> IsBetween.WhenPresentBuilder<T> isBetweenWhenPresent(T value1) {
         return isBetweenWhenPresent(() -> value1);
     }
 
-    static <T> IsBetweenWhenPresent.Builder<T> isBetweenWhenPresent(Supplier<T> valueSupplier1) {
-        return IsBetweenWhenPresent.isBetweenWhenPresent(valueSupplier1);
+    static <T> IsBetween.WhenPresentBuilder<T> isBetweenWhenPresent(Supplier<T> valueSupplier1) {
+        return IsBetween.isBetweenWhenPresent(valueSupplier1);
     }
 
     static <T> IsNotBetween.Builder<T> isNotBetween(T value1) {
@@ -628,12 +626,12 @@ static <T> IsNotBetween.Builder<T> isNotBetween(Supplier<T> valueSupplier1) {
         return IsNotBetween.isNotBetween(valueSupplier1);
     }
 
-    static <T> IsNotBetweenWhenPresent.Builder<T> isNotBetweenWhenPresent(T value1) {
+    static <T> IsNotBetween.WhenPresentBuilder<T> isNotBetweenWhenPresent(T value1) {
         return isNotBetweenWhenPresent(() -> value1);
     }
 
-    static <T> IsNotBetweenWhenPresent.Builder<T> isNotBetweenWhenPresent(Supplier<T> valueSupplier1) {
-        return IsNotBetweenWhenPresent.isNotBetweenWhenPresent(valueSupplier1);
+    static <T> IsNotBetween.WhenPresentBuilder<T> isNotBetweenWhenPresent(Supplier<T> valueSupplier1) {
+        return IsNotBetween.isNotBetweenWhenPresent(valueSupplier1);
     }
 
     // for string columns, but generic for columns with type handlers

src/main/java/org/mybatis/dynamic/sql/where/condition/IsBetween.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.
@@ -20,22 +20,85 @@
 import java.util.function.UnaryOperator;
 
 import org.mybatis.dynamic.sql.AbstractTwoValueCondition;
+import org.mybatis.dynamic.sql.util.Predicates;
 
 public class IsBetween<T> extends AbstractTwoValueCondition<T> {
 
     protected IsBetween(Supplier<T> valueSupplier1, Supplier<T> valueSupplier2) {
         super(valueSupplier1, valueSupplier2);
     }
 
-    protected IsBetween(Supplier<T> valueSupplier1, Supplier<T> valueSupplier2, BiPredicate<T, T> predicate) {
-        super(valueSupplier1, valueSupplier2, predicate);
-    }
-
     @Override
     public String renderCondition(String columnName, String placeholder1, String placeholder2) {
         return columnName + " between " + placeholder1 + " and " + placeholder2; //$NON-NLS-1$ //$NON-NLS-2$
     }
 
+    /**
+     * If renderable and the values match the predicate, returns this condition. Else returns a condition
+     *     that will not render.
+     *
+     * @deprecated replaced by {@link IsBetween#filter(BiPredicate)}
+     * @param predicate predicate applied to the values, if renderable
+     * @return this condition if renderable and the values match the predicate, otherwise a condition
+     *     that will not render.
+     */
+    @Deprecated
+    public IsBetween<T> when(BiPredicate<T, T> predicate) {
+        return filter(predicate);
+    }
+
+    /**
+     * If renderable, apply the mappings to the values and return a new condition with the new values. Else return a
+     *     condition that will not render (this).
+     *
+     * @deprecated replaced by {@link IsBetween#map(UnaryOperator, UnaryOperator)}
+     * @param mapper1 a mapping function to apply to the first value, if renderable
+     * @param mapper2 a mapping function to apply to the second value, if renderable
+     * @return a new condition with the result of applying the mappers to the values of this condition,
+     *     if renderable, otherwise a condition that will not render.
+     */
+    @Deprecated
+    public IsBetween<T> then(UnaryOperator<T> mapper1, UnaryOperator<T> mapper2) {
+        return map(mapper1, mapper2);
+    }
+
+    /**
+     * If renderable and the values match the predicate, returns this condition. Else returns a condition
+     *     that will not render.
+     *
+     * @param predicate predicate applied to the values, if renderable
+     * @return this condition if renderable and the values match the predicate, otherwise a condition
+     *     that will not render.
+     */
+    public IsBetween<T> filter(BiPredicate<T, T> predicate) {
+        if (shouldRender()) {
+            return predicate.test(value1(), value2()) ? this : EmptyIsBetween.empty();
+        } else {
+            return this;
+        }
+    }
+
+    /**
+     * If renderable, apply the mappings to the values and return a new condition with the new values. Else return a
+     *     condition that will not render (this).
+     *
+     * @param mapper1 a mapping function to apply to the first value, if renderable
+     * @param mapper2 a mapping function to apply to the second value, if renderable
+     * @return a new condition with the result of applying the mappers to the values of this condition,
+     *     if renderable, otherwise a condition that will not render.
+     */
+    public IsBetween<T> map(UnaryOperator<T> mapper1, UnaryOperator<T> mapper2) {
+        return shouldRender() ? new IsBetween<>(() -> mapper1.apply(value1()), () -> mapper2.apply(value2())) : this;
+    }
+
+    public static <T> Builder<T> isBetween(Supplier<T> valueSupplier1) {
+        return new Builder<>(valueSupplier1);
+    }
+
+    public static <T> WhenPresentBuilder<T> isBetweenWhenPresent(Supplier<T> valueSupplier1) {
+        return new WhenPresentBuilder<>(valueSupplier1);
+    }
+
     public static class Builder<T> extends AndGatherer<T, IsBetween<T>> {
         private Builder(Supplier<T> valueSupplier1) {
             super(valueSupplier1);
@@ -47,16 +110,33 @@ protected IsBetween<T> build() {
         }
     }
 
-    public static <T> Builder<T> isBetween(Supplier<T> valueSupplier1) {
-        return new Builder<>(valueSupplier1);
-    }
+    public static class WhenPresentBuilder<T> extends AndGatherer<T, IsBetween<T>> {
+        private WhenPresentBuilder(Supplier<T> valueSupplier1) {
+            super(valueSupplier1);
+        }
 
-    public IsBetween<T> when(BiPredicate<T, T> predicate) {
-        return new IsBetween<>(valueSupplier1, valueSupplier2, predicate);
+        @Override
+        protected IsBetween<T> build() {
+            return new IsBetween<>(valueSupplier1, valueSupplier2).filter(Predicates.bothPresent());
+        }
     }
 
-    public IsBetween<T> then(UnaryOperator<T> transformer1, UnaryOperator<T> transformer2) {
-        return shouldRender() ? new IsBetween<>(() -> transformer1.apply(value1()),
-                () -> transformer2.apply(value2())) : this;
+    public static class EmptyIsBetween<T> extends IsBetween<T> {
+        private static final EmptyIsBetween<?> EMPTY = new EmptyIsBetween<>();
+
+        public static <T> EmptyIsBetween<T> empty() {
+            @SuppressWarnings("unchecked")
+            EmptyIsBetween<T> t = (EmptyIsBetween<T>) EMPTY;
+            return t;
+        }
+
+        public EmptyIsBetween() {
+            super(() -> null, () -> null);
+        }
+
+        @Override
+        public boolean shouldRender() {
+            return false;
+        }
     }
 }