001// Copyright 2006-2013 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.commons.Location;
020import org.apache.tapestry5.commons.internal.services.StringInterner;
021import org.apache.tapestry5.commons.internal.util.TapestryException;
022import org.apache.tapestry5.commons.util.ExceptionUtils;
023import org.apache.tapestry5.ioc.internal.util.InternalUtils;
024import org.apache.tapestry5.services.BindingFactory;
025import org.apache.tapestry5.services.BindingSource;
026
027import java.util.Map;
028
029public class BindingSourceImpl implements BindingSource
030{
031    private final Map<String, BindingFactory> factories;
032
033    private final StringInterner interner;
034
035    public BindingSourceImpl(Map<String, BindingFactory> factories, StringInterner interner)
036    {
037        this.factories = factories;
038        this.interner = interner;
039    }
040
041    public Binding newBinding(String description, ComponentResources container, String defaultPrefix, String expression)
042    {
043        return newBinding(description, container, container, defaultPrefix, expression, null);
044    }
045
046    public Binding newBinding(String description, ComponentResources container, ComponentResources component,
047                              String defaultPrefix, String expression, Location location)
048    {
049        assert InternalUtils.isNonBlank(description);
050        assert container != null;
051        assert InternalUtils.isNonBlank(defaultPrefix);
052        assert component != null;
053
054        // TAP5-845: The expression may be the empty string. This is ok, if it's compatible with
055        // the default prefix (the empty string is not a valid property expression, but is valid
056        // as a literal string, perhaps as an informal parameter).
057
058        // Location might be null
059
060        String subexpression = expression;
061        int colonx = expression.indexOf(':');
062
063        BindingFactory factory = null;
064
065        if (colonx > 0)
066        {
067            String prefix = expression.substring(0, colonx);
068
069            factory = factories.get(prefix);
070            if (factory != null)
071                subexpression = expression.substring(colonx + 1);
072        }
073
074        if (factory == null)
075            factory = factories.get(defaultPrefix);
076
077        // And if that's null, what then? We assume that the default prefix is a valid prefix,
078        // or we'll get an NPE below and report it like any other error.
079
080        try
081        {
082            return factory.newBinding(interner.intern(description), container, component, subexpression, location);
083        } catch (Exception ex)
084        {
085            throw new TapestryException(String.format("Could not convert '%s' into a component parameter binding: %s", expression, ExceptionUtils.toMessage(ex)), location, ex);
086        }
087    }
088}