001/*
002 * (C) Copyright 2013 Nuxeo SA (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     Anahide Tchertchian
018 */
019package org.nuxeo.ecm.platform.actions.jsf;
020
021import javax.el.ELContext;
022import javax.el.ELException;
023import javax.el.ExpressionFactory;
024import javax.el.ValueExpression;
025import javax.el.VariableMapper;
026import javax.faces.context.FacesContext;
027
028import org.apache.commons.lang3.StringUtils;
029import org.nuxeo.ecm.core.api.DocumentModel;
030import org.nuxeo.ecm.core.api.NuxeoPrincipal;
031import org.nuxeo.ecm.platform.actions.AbstractActionContext;
032import org.nuxeo.ecm.platform.actions.ActionContext;
033import org.nuxeo.ecm.platform.ui.web.util.SeamContextHelper;
034
035/**
036 * @since 5.7.3
037 */
038public class JSFActionContext extends AbstractActionContext implements ActionContext {
039
040    private static final long serialVersionUID = 1L;
041
042    protected final ELContext originalContext;
043
044    protected final ExpressionFactory expressionFactory;
045
046    public JSFActionContext(FacesContext faces) {
047        super();
048        this.originalContext = faces.getELContext();
049        this.expressionFactory = faces.getApplication().getExpressionFactory();
050    }
051
052    public JSFActionContext(ELContext originalContext, ExpressionFactory expressionFactory) {
053        super();
054        this.originalContext = originalContext;
055        this.expressionFactory = expressionFactory;
056    }
057
058    @SuppressWarnings("unchecked")
059    @Override
060    public <T> T evalExpression(String expression, Class<T> expectedType) throws ELException {
061        if (StringUtils.isBlank(expression)) {
062            return null;
063        }
064        String expr = expression.trim();
065        // compatibility code, as JEXL could resolve that kind of expression:
066        // detect if expression is in brackets #{}, otherwise add it
067        if (!expr.startsWith("#{") && !expr.startsWith("${")
068        // don't confuse error messages in case of simple mistakes in the
069        // expression
070                && !expr.endsWith("}")) {
071            expr = "#{" + expr + "}";
072        }
073        ELContext finalContext = new JSFELContext(originalContext);
074        VariableMapper vm = finalContext.getVariableMapper();
075        // init default variables
076        ValueExpression documentExpr = expressionFactory.createValueExpression(getCurrentDocument(),
077                DocumentModel.class);
078        ValueExpression userExpr = expressionFactory.createValueExpression(getCurrentPrincipal(), NuxeoPrincipal.class);
079        vm.setVariable("actionContextDocument", documentExpr);
080        // add variables originally exposed by the action framework,
081        // do not add aliases currentDocument and currentUser here as they
082        // should already be available in this JSF context
083        vm.setVariable("document", documentExpr);
084        vm.setVariable("principal", userExpr);
085        // get custom context from ActionContext
086        for (String key : localVariables.keySet()) {
087            vm.setVariable(key, expressionFactory.createValueExpression(getLocalVariable(key), Object.class));
088        }
089        // expose Seam context for compatibility, although available its
090        // components should be natively exposed in this JSF context
091        putLocalVariable("SeamContext", new SeamContextHelper());
092
093        // evaluate expression
094        ValueExpression ve = expressionFactory.createValueExpression(finalContext, expr, Boolean.class);
095        return (T) ve.getValue(finalContext);
096    }
097
098    @Override
099    public boolean checkCondition(String expression) throws ELException {
100        return Boolean.TRUE.equals(evalExpression(expression, Boolean.class));
101    }
102
103}