001/*
002 * Copyright (c) 2006-2011 Nuxeo SA (http://nuxeo.com/) and others.
003 *
004 * All rights reserved. This program and the accompanying materials
005 * are made available under the terms of the Eclipse Public License v1.0
006 * which accompanies this distribution, and is available at
007 * http://www.eclipse.org/legal/epl-v10.html
008 *
009 * Contributors:
010 *     bstefanescu
011 */
012package org.nuxeo.ecm.automation.core.scripting;
013
014import org.mvel2.compiler.BlankLiteral;
015import org.mvel2.templates.CompiledTemplate;
016import org.mvel2.templates.TemplateCompiler;
017import org.mvel2.templates.TemplateRuntime;
018import org.nuxeo.ecm.automation.OperationContext;
019
020/**
021 * @author <a href="mailto:bs@nuxeo.com">Bogdan Stefanescu</a>
022 */
023public class MvelTemplate implements Expression {
024
025    private static final long serialVersionUID = 1L;
026
027    protected transient volatile CompiledTemplate compiled;
028
029    protected final String expr;
030
031    public MvelTemplate(String expr) {
032        this.expr = expr;
033    }
034
035    @Override
036    public Object eval(OperationContext ctx) {
037        if (compiled == null) {
038            compiled = TemplateCompiler.compileTemplate(expr);
039        }
040        Object obj = TemplateRuntime.execute(compiled, Scripting.initBindings(ctx));
041        return obj == null || obj.getClass().isAssignableFrom(BlankLiteral.class) ? "" : obj.toString();
042    }
043
044}