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Spring Data Relational support
/*
* Copyright 2019-2023 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
*
* https://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.springframework.data.relational.core.sql.render;
import org.springframework.data.relational.core.sql.IsNull;
import org.springframework.data.relational.core.sql.Visitable;
/**
* Renderer for {@link IsNull}. Uses a {@link RenderTarget} to call back for render results.
*
* @author Mark Paluch
* @author Jens Schauder
* @since 1.1
*/
class IsNullVisitor extends TypedSingleConditionRenderSupport {
private final RenderTarget target;
private final StringBuilder part = new StringBuilder();
IsNullVisitor(RenderContext context, RenderTarget target) {
super(context);
this.target = target;
}
@Override
Delegation leaveNested(Visitable segment) {
if (hasDelegatedRendering()) {
part.append(consumeRenderedPart());
}
return super.leaveNested(segment);
}
@Override
Delegation leaveMatched(IsNull segment) {
if (segment.isNegated()) {
part.append(" IS NOT NULL");
} else {
part.append(" IS NULL");
}
target.onRendered(part);
return super.leaveMatched(segment);
}
}