    001// Copyright 2007 The Apache Software Foundation
    002//
    003// Licensed under the Apache License, Version 2.0 (the "License");
    004// you may not use this file except in compliance with the License.
    005// You may obtain a copy of the License at
    006//
    007//     http://www.apache.org/licenses/LICENSE-2.0
    008//
    009// Unless required by applicable law or agreed to in writing, software
    010// distributed under the License is distributed on an "AS IS" BASIS,
    011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012// See the License for the specific language governing permissions and
    013// limitations under the License.
    014
    015package org.apache.tapestry5.ioc.internal.services;
    016
    017import org.apache.tapestry5.ioc.AnnotationProvider;
    018import org.apache.tapestry5.ioc.ObjectLocator;
    019import org.apache.tapestry5.ioc.ObjectProvider;
    020import org.apache.tapestry5.ioc.annotations.IntermediateType;
    021import org.apache.tapestry5.ioc.annotations.Value;
    022import org.apache.tapestry5.ioc.services.Builtin;
    023import org.apache.tapestry5.ioc.services.SymbolSource;
    024import org.apache.tapestry5.ioc.services.TypeCoercer;
    025
    026/**
    027 * Provides an object when the {@link Value} annotation is present. The string value has symbols expanded, and then is
    028 * {@link TypeCoercer coerced} to the associated type.   The value may first be coerced to an intermediate type if the
    029 * {@link IntermediateType} annotation is present.
    030 */
    031public class ValueObjectProvider implements ObjectProvider
    032{
    033    private final SymbolSource symbolSource;
    034
    035    private final TypeCoercer typeCoercer;
    036
    037    public ValueObjectProvider(@Builtin SymbolSource symbolSource,
    038
    039                               @Builtin TypeCoercer typeCoercer)
    040    {
    041        this.symbolSource = symbolSource;
    042        this.typeCoercer = typeCoercer;
    043    }
    044
    045    @Override
    046    public <T> T provide(Class<T> objectType, AnnotationProvider annotationProvider, ObjectLocator locator)
    047    {
    048        Value annotation = annotationProvider.getAnnotation(Value.class);
    049
    050        if (annotation == null) return null;
    051
    052        String value = annotation.value();
    053        Object expanded = symbolSource.expandSymbols(value);
    054
    055        IntermediateType intermediate = annotationProvider.getAnnotation(IntermediateType.class);
    056
    057        if (intermediate != null) expanded = typeCoercer.coerce(expanded, intermediate.value());
    058
    059        return typeCoercer.coerce(expanded, objectType);
    060    }
    061}