org.kuali.rice.edl.impl.components.SelectControlEDLComponent.java Source code

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Here is the source code for org.kuali.rice.edl.impl.components.SelectControlEDLComponent.java

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/**
 * Copyright 2005-2014 The Kuali Foundation
 *
 * Licensed under the Educational Community License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.opensource.org/licenses/ecl2.php
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.kuali.rice.edl.impl.components;

import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpressionException;

import org.apache.commons.lang.StringUtils;
import org.kuali.rice.edl.impl.EDLContext;
import org.kuali.rice.edl.impl.EDLModelComponent;
import org.kuali.rice.kew.rule.xmlrouting.XPathHelper;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

/**
 * Looks at a field definition for a select field and attempts to analyze and resolve any valuesGroups based on document data.
 * The result of this is to take a fieldDef that has a valuesGroup and either remove it if it does not match or replace the
 * <valuesGroup> element with a series of <values> elements that include the values contained with the values group.
 * 
 * <p>This allows for <select> fields to be dependent upon one another. 
 * 
 * @author Kuali Rice Team (rice.collab@kuali.org)
 */
public class SelectControlEDLComponent implements EDLModelComponent {

    public void updateDOM(Document dom, Element currentDefinitionElement, EDLContext edlContext) {
        Element currentVersion = VersioningPreprocessor.findCurrentVersion(dom);
        XPath xPath = XPathHelper.newXPath(dom);
        try {
            NodeList selectFieldDefs = (NodeList) xPath.evaluate(
                    "//fieldDef[display/type = 'select' and display/valuesGroup] | //fieldDef[display/type = 'select_refresh' and display/valuesGroup]",
                    dom, XPathConstants.NODESET);
            for (int fIndex = 0; fIndex < selectFieldDefs.getLength(); fIndex++) {
                Element fieldDef = (Element) selectFieldDefs.item(fIndex);
                NodeList valuesGroups = (NodeList) xPath.evaluate("./display/valuesGroup", fieldDef,
                        XPathConstants.NODESET);
                for (int index = 0; index < valuesGroups.getLength(); index++) {
                    Element valuesGroupElem = (Element) valuesGroups.item(index);
                    NodeList dependsOnFields = (NodeList) xPath.evaluate("./dependsOn/field", valuesGroupElem,
                            XPathConstants.NODESET);
                    String fieldEvalExpression = "";
                    for (int dIndex = 0; dIndex < dependsOnFields.getLength(); dIndex++) {
                        if (!StringUtils.isBlank(fieldEvalExpression)) {
                            fieldEvalExpression += " and ";
                        }
                        Element fieldElem = (Element) dependsOnFields.item(dIndex);
                        String name = fieldElem.getAttribute("name");
                        String value = fieldElem.getTextContent();
                        fieldEvalExpression += "./field[@name='" + name + "']/value = '" + value + "'";
                    }
                    if ((Boolean) xPath.evaluate(fieldEvalExpression, currentVersion, XPathConstants.BOOLEAN)) {
                        includeValuesGroup(valuesGroupElem);
                    } else {
                        // remove the valuesGroup as it did not match
                        valuesGroupElem.getParentNode().removeChild(valuesGroupElem);
                    }
                }
            }
        } catch (XPathExpressionException e) {
            throw new RuntimeException("Failed to evaluate xpath expression.", e);
        }
    }

    protected void includeValuesGroup(Element valuesGroupElem) {
        Element valuesGroupParent = (Element) valuesGroupElem.getParentNode();
        NodeList valuesGroupChildren = valuesGroupElem.getChildNodes();

        for (int index = 0; index < valuesGroupChildren.getLength(); index++) {
            Node item = valuesGroupChildren.item(index);
            if (Node.ELEMENT_NODE == item.getNodeType() && item.getNodeName().equals("values")) {
                valuesGroupParent.insertBefore(item, valuesGroupElem);
            }
        }
        valuesGroupParent.removeChild(valuesGroupElem);
    }

}