1 /*
2 * Copyright 2016-2025 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * https://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package org.mybatis.dynamic.sql;
17
18 import java.util.function.BooleanSupplier;
19 import java.util.function.Supplier;
20
21 import org.mybatis.dynamic.sql.render.RenderingContext;
22 import org.mybatis.dynamic.sql.util.FragmentAndParameters;
23
24 public abstract class AbstractNoValueCondition<T> implements RenderableCondition<T> {
25
26 protected <S extends AbstractNoValueCondition<?>> S filterSupport(BooleanSupplier booleanSupplier,
27 Supplier<S> emptySupplier, S self) {
28 if (isEmpty()) {
29 return self;
30 } else {
31 return booleanSupplier.getAsBoolean() ? self : emptySupplier.get();
32 }
33 }
34
35 public abstract String operator();
36
37 @Override
38 public FragmentAndParameters renderCondition(RenderingContext renderingContext, BindableColumn<T> leftColumn) {
39 return FragmentAndParameters.fromFragment(operator());
40 }
41
42 /**
43 * Conditions may implement Filterable to add optionality to rendering.
44 *
45 * <p>If a condition is Filterable, then a user may add a filter to the usage of the condition that makes a decision
46 * whether to render the condition at runtime. Conditions that fail the filter will be dropped from the
47 * rendered SQL.
48 *
49 * <p>Implementations of Filterable may call
50 * {@link AbstractNoValueCondition#filterSupport(BooleanSupplier, Supplier, AbstractNoValueCondition)} as
51 * a common implementation of the filtering algorithm.
52 */
53 public interface Filterable {
54 /**
55 * If renderable and the supplier returns true, returns this condition. Else returns a condition that will not
56 * render.
57 *
58 * @param booleanSupplier
59 * function that specifies whether the condition should render
60 * @param <S>
61 * condition type - not used except for compilation compliance
62 *
63 * @return this condition if renderable and the supplier returns true, otherwise a condition that will not
64 * render.
65 */
66 <S> AbstractNoValueCondition<S> filter(BooleanSupplier booleanSupplier);
67 }
68 }