001/*
002 * (C) Copyright 2006-2007 Nuxeo SAS (http://nuxeo.com/) and contributors.
003 *
004 * All rights reserved. This program and the accompanying materials
005 * are made available under the terms of the GNU Lesser General Public License
006 * (LGPL) version 2.1 which accompanies this distribution, and is available at
007 * http://www.gnu.org/licenses/lgpl.html
008 *
009 * This library is distributed in the hope that it will be useful,
010 * but WITHOUT ANY WARRANTY; without even the implied warranty of
011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012 * Lesser General Public License for more details.
013 *
014 * Contributors:
015 *     <a href="mailto:at@nuxeo.com">Anahide Tchertchian</a>
016 *
017 * $Id: LayoutRowTagHandler.java 30553 2008-02-24 15:51:31Z atchertchian $
018 */
019
020package org.nuxeo.ecm.platform.forms.layout.facelets;
021
022import java.io.IOException;
023import java.util.ArrayList;
024import java.util.HashMap;
025import java.util.List;
026import java.util.Map;
027
028import javax.el.ELException;
029import javax.el.ValueExpression;
030import javax.faces.FacesException;
031import javax.faces.component.UIComponent;
032import javax.faces.view.facelets.FaceletContext;
033import javax.faces.view.facelets.FaceletHandler;
034import javax.faces.view.facelets.TagAttribute;
035import javax.faces.view.facelets.TagConfig;
036import javax.faces.view.facelets.TagHandler;
037
038import org.apache.commons.logging.Log;
039import org.apache.commons.logging.LogFactory;
040import org.nuxeo.ecm.platform.forms.layout.api.Layout;
041import org.nuxeo.ecm.platform.forms.layout.api.LayoutRow;
042
043/**
044 * Layout row recursion tag handler.
045 * <p>
046 * Iterate over the layout rows and apply next handlers as many times as needed.
047 * <p>
048 * Only works when used inside a tag using the {@link LayoutTagHandler} template client.
049 *
050 * @author <a href="mailto:at@nuxeo.com">Anahide Tchertchian</a>
051 */
052public class LayoutRowTagHandler extends TagHandler {
053
054    private static final Log log = LogFactory.getLog(LayoutRowTagHandler.class);
055
056    protected final TagConfig config;
057
058    public LayoutRowTagHandler(TagConfig config) {
059        super(config);
060        this.config = config;
061    }
062
063    /**
064     * For each row in layout, exposes row variables and applies next handler.
065     * <p>
066     * Needs layout to be exposed in context, so works in conjunction with {@link LayoutTagHandler}.
067     * <p>
068     * Row variables exposed: {@link RenderVariables.rowVariables#layoutRow} and
069     * {@link RenderVariables.rowVariables#layoutRowIndex}, as well as
070     * {@link RenderVariables.columnVariables#layoutColumn} and
071     * {@link RenderVariables.columnVariables#layoutColumnIndex}, that act are aliases.
072     */
073    public void apply(FaceletContext ctx, UIComponent parent) throws IOException, FacesException, ELException {
074        // resolve rows from layout in context
075        Layout layout = null;
076        String layoutVariableName = RenderVariables.layoutVariables.layout.name();
077        FaceletHandlerHelper helper = new FaceletHandlerHelper(ctx, config);
078        TagAttribute layoutAttribute = helper.createAttribute(layoutVariableName,
079                String.format("#{%s}", layoutVariableName));
080        if (layoutAttribute != null) {
081            layout = (Layout) layoutAttribute.getObject(ctx, Layout.class);
082        }
083        if (layout == null) {
084            log.error("Could not resolve layout " + layoutAttribute);
085            return;
086        }
087
088        LayoutRow[] rows = layout.getRows();
089        if (rows == null || rows.length == 0) {
090            return;
091        }
092
093        int rowCounter = 0;
094        for (LayoutRow row : rows) {
095            // expose row variables
096            Map<String, ValueExpression> variables = new HashMap<String, ValueExpression>();
097            ValueExpression rowVe = ctx.getExpressionFactory().createValueExpression(row, LayoutRow.class);
098            variables.put(RenderVariables.rowVariables.layoutRow.name(), rowVe);
099            variables.put(RenderVariables.columnVariables.layoutColumn.name(), rowVe);
100            ValueExpression rowIndexVe = ctx.getExpressionFactory().createValueExpression(Integer.valueOf(rowCounter),
101                    Integer.class);
102            variables.put(RenderVariables.rowVariables.layoutRowIndex.name(), rowIndexVe);
103            variables.put(RenderVariables.columnVariables.layoutColumnIndex.name(), rowIndexVe);
104
105            List<String> blockedPatterns = new ArrayList<String>();
106            blockedPatterns.add(RenderVariables.rowVariables.layoutRow.name());
107            blockedPatterns.add(RenderVariables.rowVariables.layoutRowIndex.name());
108            blockedPatterns.add(RenderVariables.columnVariables.layoutColumn.name());
109            blockedPatterns.add(RenderVariables.columnVariables.layoutColumnIndex.name());
110
111            FaceletHandler handler = helper.getAliasTagHandler(row.getTagConfigId(), variables, blockedPatterns,
112                    nextHandler);
113            handler.apply(ctx, parent);
114            rowCounter++;
115        }
116    }
117}