    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
    015    package org.apache.tapestry5.ioc.internal.services;
    016
    017    import org.apache.tapestry5.ioc.AnnotationProvider;
    018    import org.apache.tapestry5.ioc.ObjectLocator;
    019    import org.apache.tapestry5.ioc.ObjectProvider;
    020    import org.apache.tapestry5.ioc.annotations.IntermediateType;
    021    import org.apache.tapestry5.ioc.annotations.Value;
    022    import org.apache.tapestry5.ioc.services.Builtin;
    023    import org.apache.tapestry5.ioc.services.SymbolSource;
    024    import 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     */
    031    public 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        public <T> T provide(Class<T> objectType, AnnotationProvider annotationProvider, ObjectLocator locator)
    046        {
    047            Value annotation = annotationProvider.getAnnotation(Value.class);
    048
    049            if (annotation == null) return null;
    050
    051            String value = annotation.value();
    052            Object expanded = symbolSource.expandSymbols(value);
    053
    054            IntermediateType intermediate = annotationProvider.getAnnotation(IntermediateType.class);
    055
    056            if (intermediate != null) expanded = typeCoercer.coerce(expanded, intermediate.value());
    057
    058            return typeCoercer.coerce(expanded, objectType);
    059        }
    060    }