[MSHARED-1412] Allow to customize Interpolator used by filter

[kwin]

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[gnodet]

@kwin is there an immediate use case for this ? which maven plugin will use it ? just curious...

[kwin]

The use case for me is https://issues.apache.org/jira/browse/JCRVLT-757 (outside the Maven project). But I can imagine that for some advanced use cases also the maven-resources-plugin could leverage that (with automatically registered Sisu components)...

[olamy]

is there anything you could do with this https://maven.apache.org/plugins/maven-resources-plugin/examples/custom-resource-filters.html ?

[kwin]

The problem is I want the default filter behaviour, which is currently not reusable in custom filter (i.e. all the code from

maven-filtering/src/main/java/org/apache/maven/shared/filtering/BaseFilter.java

Lines 74 to 181 in 9d528d0

	public List<FilterWrapper> getDefaultFilterWrappers(final AbstractMavenFilteringRequest request)
	throws MavenFilteringException {
	// backup values
	boolean supportMultiLineFiltering = request.isSupportMultiLineFiltering();
	request.setSupportMultiLineFiltering(supportMultiLineFiltering);
	// Here we build some properties which will be used to read some properties files
	// to interpolate the expression ${ } in this properties file
	// Take a copy of filterProperties to ensure that evaluated filterTokens are not propagated
	// to subsequent filter files. Note: this replicates current behaviour and seems to make sense.
	final Properties baseProps = new Properties();
	// Project properties
	if (request.getMavenProject() != null) {
	baseProps.putAll(
	request.getMavenProject().getProperties() == null
	? Collections.emptyMap()
	: request.getMavenProject().getProperties());
	}
	// TODO this is NPE free but do we consider this as normal
	// or do we have to throw an MavenFilteringException with mavenSession cannot be null
	//
	// khmarbaise: 2016-05-21:
	// If we throw an MavenFilteringException tests will fail which is
	// caused by for example:
	// void copyFile( File from, final File to, boolean filtering, List<FileUtils.FilterWrapper> filterWrappers,
	// String encoding )
	// in MavenFileFilter interface where no MavenSession is given.
	// So changing here to throw a MavenFilteringException would make
	// it necessary to change the interface or we need to find a better solution.
	//
	if (request.getMavenSession() != null) {
	// User properties have precedence over system properties
	putAll(baseProps, request.getMavenSession().getSystemProperties());
	putAll(baseProps, request.getMavenSession().getUserProperties());
	}
	// now we build properties to use for resources interpolation
	final Properties filterProperties = new Properties();
	File basedir =
	request.getMavenProject() != null ? request.getMavenProject().getBasedir() : new File(".");
	loadProperties(filterProperties, basedir, request.getFileFilters(), baseProps);
	if (filterProperties.isEmpty()) {
	putAll(filterProperties, baseProps);
	}
	if (request.getMavenProject() != null) {
	if (request.isInjectProjectBuildFilters()) {
	List<String> buildFilters =
	new ArrayList<>(request.getMavenProject().getBuild().getFilters());
	// JDK-8015656: (coll) unexpected NPE from removeAll
	if (request.getFileFilters() != null) {
	buildFilters.removeAll(request.getFileFilters());
	}
	loadProperties(filterProperties, basedir, buildFilters, baseProps);
	}
	// Project properties
	filterProperties.putAll(
	request.getMavenProject().getProperties() == null
	? Collections.emptyMap()
	: request.getMavenProject().getProperties());
	}
	if (request.getMavenSession() != null) {
	// User properties have precedence over system properties
	putAll(filterProperties, request.getMavenSession().getSystemProperties());
	putAll(filterProperties, request.getMavenSession().getUserProperties());
	}
	if (request.getAdditionalProperties() != null) {
	// additional properties wins
	putAll(filterProperties, request.getAdditionalProperties());
	}
	List<FilterWrapper> defaultFilterWrappers =
	new ArrayList<>(request.getDelimiters().size() + 1);
	if (getLogger().isDebugEnabled()) {
	getLogger().debug("properties used:");
	for (String s : new TreeSet<>(filterProperties.stringPropertyNames())) {
	getLogger().debug(s + ": " + filterProperties.getProperty(s));
	}
	}
	final ValueSource propertiesValueSource = new PropertiesBasedValueSource(filterProperties);
	FilterWrapper wrapper = new Wrapper(
	request.getDelimiters(),
	request.getMavenProject(),
	request.getMavenSession(),
	propertiesValueSource,
	request.getProjectStartExpressions(),
	request.getEscapeString(),
	request.isEscapeWindowsPaths(),
	request.isSupportMultiLineFiltering());
	defaultFilterWrappers.add(wrapper);
	return defaultFilterWrappers;
	}

and

maven-filtering/src/main/java/org/apache/maven/shared/filtering/BaseFilter.java

Lines 217 to 323 in 9d528d0

	private static final class Wrapper extends FilterWrapper {
	private LinkedHashSet<String> delimiters;
	private MavenProject project;
	private ValueSource propertiesValueSource;
	private List<String> projectStartExpressions;
	private String escapeString;
	private boolean escapeWindowsPaths;
	private final MavenSession mavenSession;
	private boolean supportMultiLineFiltering;
	Wrapper(
	LinkedHashSet<String> delimiters,
	MavenProject project,
	MavenSession mavenSession,
	ValueSource propertiesValueSource,
	List<String> projectStartExpressions,
	String escapeString,
	boolean escapeWindowsPaths,
	boolean supportMultiLineFiltering) {
	super();
	this.delimiters = delimiters;
	this.project = project;
	this.mavenSession = mavenSession;
	this.propertiesValueSource = propertiesValueSource;
	this.projectStartExpressions = projectStartExpressions;
	this.escapeString = escapeString;
	this.escapeWindowsPaths = escapeWindowsPaths;
	this.supportMultiLineFiltering = supportMultiLineFiltering;
	}
	@Override
	public Reader getReader(Reader reader) {
	Interpolator interpolator = createInterpolator(
	delimiters,
	projectStartExpressions,
	propertiesValueSource,
	project,
	mavenSession,
	escapeString,
	escapeWindowsPaths);
	MultiDelimiterInterpolatorFilterReaderLineEnding filterReader =
	new MultiDelimiterInterpolatorFilterReaderLineEnding(
	reader, interpolator, supportMultiLineFiltering);
	final RecursionInterceptor ri;
	if (projectStartExpressions != null && !projectStartExpressions.isEmpty()) {
	ri = new PrefixAwareRecursionInterceptor(projectStartExpressions, true);
	} else {
	ri = new SimpleRecursionInterceptor();
	}
	filterReader.setRecursionInterceptor(ri);
	filterReader.setDelimiterSpecs(delimiters);
	filterReader.setInterpolateWithPrefixPattern(false);
	filterReader.setEscapeString(escapeString);
	return filterReader;
	}
	}
	private static Interpolator createInterpolator(
	LinkedHashSet<String> delimiters,
	List<String> projectStartExpressions,
	ValueSource propertiesValueSource,
	MavenProject project,
	MavenSession mavenSession,
	String escapeString,
	boolean escapeWindowsPaths) {
	MultiDelimiterStringSearchInterpolator interpolator = new MultiDelimiterStringSearchInterpolator();
	interpolator.setDelimiterSpecs(delimiters);
	interpolator.addValueSource(propertiesValueSource);
	if (project != null) {
	interpolator.addValueSource(new PrefixedObjectValueSource(projectStartExpressions, project, true));
	}
	if (mavenSession != null) {
	interpolator.addValueSource(new PrefixedObjectValueSource("session", mavenSession));
	final Settings settings = mavenSession.getSettings();
	if (settings != null) {
	interpolator.addValueSource(new PrefixedObjectValueSource("settings", settings));
	interpolator.addValueSource(
	new SingleResponseValueSource("localRepository", settings.getLocalRepository()));
	}
	}
	interpolator.setEscapeString(escapeString);
	if (escapeWindowsPaths) {
	interpolator.addPostProcessor((expression, value) ->
	(value instanceof String) ? FilteringUtils.escapeWindowsPath((String) value) : value);
	}
	return interpolator;
	}
	}

would need to be duplicated for a custom filter). The interpolator customizer allows to leverage the default filterwhile still extending interpolation features of it.

[kwin]

If there is no further input I will merge at the end of the week.