BeanContextAccess.java

/*
 * Copyright 2017-2023 original 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 io.micronaut.expressions.parser.ast.access;

import io.micronaut.core.annotation.Internal;
import io.micronaut.core.annotation.NonNull;
import io.micronaut.core.expressions.ExpressionEvaluationContext;
import io.micronaut.core.reflect.ReflectionUtils;
import io.micronaut.expressions.parser.ast.ExpressionNode;
import io.micronaut.expressions.parser.ast.types.TypeIdentifier;
import io.micronaut.expressions.parser.compilation.ExpressionCompilationContext;
import io.micronaut.expressions.parser.compilation.ExpressionVisitorContext;
import io.micronaut.inject.ast.ClassElement;
import io.micronaut.sourcegen.model.ExpressionDef;
import io.micronaut.sourcegen.model.TypeDef;

import java.lang.reflect.Method;

/**
 * Expression AST node used for to retrieve beans from bean context.
 *
 * @author Sergey Gavrilov
 * @since 4.0.0
 */
@Internal
public class BeanContextAccess extends ExpressionNode {

    private static final Method GET_BEAN_METHOD =
        ReflectionUtils.getRequiredMethod(ExpressionEvaluationContext.class, "getBean", Class.class);

    private final TypeIdentifier typeIdentifier;

    public BeanContextAccess(TypeIdentifier typeIdentifier) {
        this.typeIdentifier = typeIdentifier;
    }

    @Override
    protected ExpressionDef generateExpression(ExpressionCompilationContext ctx) {
        TypeDef beanType = typeIdentifier.resolveType(ctx);
        return ctx.expressionEvaluationContextVar()
            .invoke(GET_BEAN_METHOD, ExpressionDef.constant(beanType))
            .cast(beanType);
    }

    @Override
    protected ClassElement doResolveClassElement(ExpressionVisitorContext ctx) {
        return typeIdentifier.resolveClassElement(ctx);
    }

    @Override
    protected TypeDef doResolveType(@NonNull ExpressionVisitorContext ctx) {
        return typeIdentifier.doResolveType(ctx);
    }
}