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