001// Copyright 2006, 2007, 2008, 2009, 2010, 2011 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.internal.services;
016
017import org.apache.tapestry5.Binding;
018import org.apache.tapestry5.ComponentResources;
019import org.apache.tapestry5.ioc.Location;
020import org.apache.tapestry5.ioc.internal.util.InternalUtils;
021import org.apache.tapestry5.ioc.internal.util.TapestryException;
022import org.apache.tapestry5.services.BindingFactory;
023import org.apache.tapestry5.services.BindingSource;
024
025import java.util.Map;
026
027public class BindingSourceImpl implements BindingSource
028{
029    private final Map<String, BindingFactory> factories;
030
031    private final StringInterner interner;
032
033    public BindingSourceImpl(Map<String, BindingFactory> factories, StringInterner interner)
034    {
035        this.factories = factories;
036        this.interner = interner;
037    }
038
039    public Binding newBinding(String description, ComponentResources container, String defaultPrefix, String expression)
040    {
041        return newBinding(description, container, container, defaultPrefix, expression, null);
042    }
043
044    public Binding newBinding(String description, ComponentResources container, ComponentResources component,
045                              String defaultPrefix, String expression, Location location)
046    {
047        assert InternalUtils.isNonBlank(description);
048        assert container != null;
049        assert InternalUtils.isNonBlank(defaultPrefix);
050        assert component != null;
051
052        // TAP5-845: The expression may be the empty string. This is ok, if it's compatible with
053        // the default prefix (the empty string is not a valid property expression, but is valid
054        // as a literal string, perhaps as an informal parameter).
055
056        // Location might be null
057
058        String subexpression = expression;
059        int colonx = expression.indexOf(':');
060
061        BindingFactory factory = null;
062
063        if (colonx > 0)
064        {
065            String prefix = expression.substring(0, colonx);
066
067            factory = factories.get(prefix);
068            if (factory != null)
069                subexpression = expression.substring(colonx + 1);
070        }
071
072        if (factory == null)
073            factory = factories.get(defaultPrefix);
074
075        // And if that's null, what then? We assume that the default prefix is a valid prefix,
076        // or we'll get an NPE below and report it like any other error.
077
078        try
079        {
080            return factory.newBinding(interner.intern(description), container, component, subexpression, location);
081        } catch (Exception ex)
082        {
083            throw new TapestryException(String.format("Could not convert '%s' into a component parameter binding: %s", expression, InternalUtils.toMessage(ex)), location, ex);
084        }
085    }
086}