Add ExpressionMapper interface

source/net/filebot/cli/ArgumentBean.java

@@ -43,6 +43,7 @@ import net.filebot.format.ExpressionFileFilter;
 import net.filebot.format.ExpressionFileFormat;
 import net.filebot.format.ExpressionFilter;
 import net.filebot.format.ExpressionFormat;
+import net.filebot.format.ExpressionMapper;
 import net.filebot.hash.HashType;
 import net.filebot.subtitle.SubtitleFormat;
 import net.filebot.subtitle.SubtitleNaming;
@@ -71,9 +72,12 @@ public class ArgumentBean {
 	@Option(name = "--conflict", usage = "Conflict resolution", metaVar = "[skip, override, auto, index, fail]")
 	public String conflict = "skip";
 
-	@Option(name = "--filter", usage = "Match filter expression", handler = GroovyExpressionHandler.class)
+	@Option(name = "--filter", usage = "Filter expression", handler = GroovyExpressionHandler.class)
 	public String filter = null;
 
+	@Option(name = "--xem", usage = "XEM expression", handler = GroovyExpressionHandler.class)
+	public String mapper = null;
+
 	@Option(name = "--format", usage = "Format expression", handler = GroovyExpressionHandler.class)
 	public String format;
 
@@ -266,6 +270,10 @@ public class ArgumentBean {
 		return filter == null ? FILES : new ExpressionFileFilter(filter, xattr::getMetaInfo);
 	}
 
+	public ExpressionMapper getExpressionMapper() throws Exception {
+		return mapper == null ? null : new ExpressionMapper(mapper);
+	}
+
 	public Datasource getDatasource() {
 		return db == null ? null : WebServices.getService(db);
 	}

source/net/filebot/format/ExpressionMapper.java

@@ -0,0 +1,48 @@
+package net.filebot.format;
+
+import static net.filebot.format.ExpressionFormat.*;
+
+import java.security.AccessController;
+
+import javax.script.Bindings;
+import javax.script.CompiledScript;
+import javax.script.ScriptContext;
+import javax.script.ScriptException;
+import javax.script.SimpleScriptContext;
+
+import org.codehaus.groovy.runtime.typehandling.DefaultTypeTransformation;
+
+public class ExpressionMapper {
+
+	private final String expression;
+	private final CompiledScript compiledExpression;
+
+	public ExpressionMapper(String expression) throws ScriptException {
+		this.expression = expression;
+		this.compiledExpression = new SecureCompiledScript(compileScriptlet(asExpression(expression)));
+	}
+
+	public String getExpression() {
+		return expression;
+	}
+
+	public <T> Object map(Object value, Class<T> type) throws ScriptException {
+		return map(new ExpressionBindings(value), type);
+	}
+
+	public <T> Object map(Bindings bindings, Class<T> type) throws ScriptException {
+		// use privileged bindings so we are not restricted by the script sandbox
+		Bindings priviledgedBindings = PrivilegedInvocation.newProxy(Bindings.class, bindings, AccessController.getContext());
+
+		// initialize script context with the privileged bindings
+		ScriptContext context = new SimpleScriptContext();
+		context.setBindings(priviledgedBindings, ScriptContext.GLOBAL_SCOPE);
+
+		// evaluate user script
+		Object value = compiledExpression.eval(context);
+
+		// value as target type
+		return DefaultTypeTransformation.castToType(value, type);
+	}
+
+}