maven-model-builder/src/main/java/org/apache/maven/model/interpolation/AbstractStringBasedModelInterpolator.java

package org.apache.maven.model.interpolation;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import java.io.File;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Properties;

import javax.inject.Inject;

import org.apache.maven.model.Model;
import org.apache.maven.model.building.ModelBuildingRequest;
import org.apache.maven.model.path.PathTranslator;
import org.apache.maven.model.path.UrlNormalizer;
import org.codehaus.plexus.interpolation.AbstractValueSource;
import org.codehaus.plexus.interpolation.InterpolationPostProcessor;
import org.codehaus.plexus.interpolation.MapBasedValueSource;
import org.codehaus.plexus.interpolation.PrefixAwareRecursionInterceptor;
import org.codehaus.plexus.interpolation.PrefixedObjectValueSource;
import org.codehaus.plexus.interpolation.PrefixedValueSourceWrapper;
import org.codehaus.plexus.interpolation.RecursionInterceptor;
import org.codehaus.plexus.interpolation.ValueSource;

/**
 * Use a regular expression search to find and resolve expressions within the POM.
 *
 * @author jdcasey Created on Feb 3, 2005
 */
public abstract class AbstractStringBasedModelInterpolator
    implements ModelInterpolator
{
    private static final List<String> PROJECT_PREFIXES = Collections.singletonList( "project." );

    private static final Collection<String> TRANSLATED_PATH_EXPRESSIONS;

    static
    {
        Collection<String> translatedPrefixes = new HashSet<>();

        // MNG-1927, MNG-2124, MNG-3355:
        // If the build section is present and the project directory is non-null, we should make
        // sure interpolation of the directories below uses translated paths.
        // Afterward, we'll double back and translate any paths that weren't covered during interpolation via the
        // code below...
        translatedPrefixes.add( "build.directory" );
        translatedPrefixes.add( "build.outputDirectory" );
        translatedPrefixes.add( "build.testOutputDirectory" );
        translatedPrefixes.add( "build.sourceDirectory" );
        translatedPrefixes.add( "build.testSourceDirectory" );
        translatedPrefixes.add( "build.scriptSourceDirectory" );
        translatedPrefixes.add( "reporting.outputDirectory" );

        TRANSLATED_PATH_EXPRESSIONS = translatedPrefixes;
    }

    private final PathTranslator pathTranslator;
    private final UrlNormalizer urlNormalizer;
    private final ModelVersionProcessor versionProcessor;

    @Inject
    public AbstractStringBasedModelInterpolator( PathTranslator pathTranslator, UrlNormalizer urlNormalizer,
                                                 ModelVersionProcessor processor )
    {
        this.pathTranslator = pathTranslator;
        this.urlNormalizer = urlNormalizer;
        this.versionProcessor = processor;
    }

    protected List<ValueSource> createValueSources( final Model model, final File projectDir,
                                                    final ModelBuildingRequest config )
    {
        Properties modelProperties = model.getProperties();

        ValueSource projectPrefixValueSource = new PrefixedObjectValueSource( PROJECT_PREFIXES, model, false );

        // NOTE: Order counts here!
        List<ValueSource> valueSources = new ArrayList<>( 8 );

        if ( projectDir != null )
        {
            ValueSource basedirValueSource = new PrefixedValueSourceWrapper( new AbstractValueSource( false )
            {
                @Override
                public Object getValue( String expression )
                {
                    if ( "basedir".equals( expression ) )
                    {
                        return projectDir.getAbsolutePath();
                    }
                    return null;
                }
            }, PROJECT_PREFIXES, true );
            valueSources.add( basedirValueSource );

            ValueSource baseUriValueSource = new PrefixedValueSourceWrapper( new AbstractValueSource( false )
            {
                @Override
                public Object getValue( String expression )
                {
                    if ( "baseUri".equals( expression ) )
                    {
                        return projectDir.getAbsoluteFile().toPath().toUri().toASCIIString();
                    }
                    return null;
                }
            }, PROJECT_PREFIXES, false );
            valueSources.add( baseUriValueSource );
            valueSources.add( new BuildTimestampValueSource( config.getBuildStartTime(), modelProperties ) );
        }

        valueSources.add( projectPrefixValueSource );

        valueSources.add( new MapBasedValueSource( config.getUserProperties() ) );

        // Overwrite existing values in model properties. Otherwise it's not possible
        // to define the version via command line: mvn -Drevision=6.5.7 ...
        versionProcessor.overwriteModelProperties( modelProperties, config );

        valueSources.add( new MapBasedValueSource( modelProperties ) );

        valueSources.add( new MapBasedValueSource( config.getSystemProperties() ) );

        valueSources.add( new AbstractValueSource( false )
        {
            @Override
            public Object getValue( String expression )
            {
                return config.getSystemProperties().getProperty( "env." + expression );
            }
        } );

        return valueSources;
    }

    protected List<? extends InterpolationPostProcessor> createPostProcessors( final Model model,
                                                                               final File projectDir,
                                                                               final ModelBuildingRequest config )
    {
        List<InterpolationPostProcessor> processors = new ArrayList<>( 2 );
        if ( projectDir != null )
        {
            processors.add( new PathTranslatingPostProcessor( PROJECT_PREFIXES, TRANSLATED_PATH_EXPRESSIONS,
                                                              projectDir, pathTranslator ) );
        }
        processors.add( new UrlNormalizingPostProcessor( urlNormalizer ) );
        return processors;
    }

    protected RecursionInterceptor createRecursionInterceptor()
    {
        return new PrefixAwareRecursionInterceptor( PROJECT_PREFIXES );
    }

}