org.toobsframework.tags.FormatHelper.java Source code

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Here is the source code for org.toobsframework.tags.FormatHelper.java

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/*
 * This file is licensed to the Toobs Framework Group under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The Toobs Framework Group licenses this file to You under the Apache 
 * 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.apache.org/licenses/LICENSE-2.0
 *
 * 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.toobsframework.tags;

import java.util.ArrayList;
import java.util.List;
import java.util.Locale;

import javax.xml.transform.TransformerException;

import org.apache.xalan.extensions.XSLProcessorContext;
import org.apache.xalan.templates.ElemExtensionCall;
import org.apache.xalan.templates.ElemTextLiteral;
import org.apache.xalan.templates.ElemValueOf;
import org.apache.xalan.transformer.TransformerImpl;
import org.apache.xpath.XPath;
import org.apache.xpath.XPathContext;
import org.apache.xpath.objects.XObject;
import org.apache.xpath.objects.XRTreeFragSelectWrapper;
import org.springframework.web.servlet.DispatcherServlet;
import org.springframework.web.servlet.LocaleResolver;

import org.toobsframework.pres.xsl.ComponentTransformerHelper;
import org.toobsframework.transformpipeline.domain.IXMLTransformer;
import org.toobsframework.util.IRequest;

import org.w3c.dom.Node;

public class FormatHelper extends TagBase {

    private static final String FORMAT_HELPER_PARAMETERS = "formatHelperParameters";

    /**
     * Public Tag - Message - insert a resource bundle message in the result stream
     * <p>
     * <pre><code>
     *   &lt;fmt:message key="<i>key</i>"&gt;
     *   &lt;/fmt:message>
     * </code></pre>
     * 
     * implicit DTD for message
     * 
     * <pre><code>
     * &lt;!ELEMENT fmt:message (fmt:param*)&gt
     * &lt;!ATTLIST fmt:message
     * key CDATA #REQUIRED
     * </code></pre>
     * 
     * Where
     * <p>
     * <ul>
     * <li>key - is the resource bundle message key
     * </ul>
     */
    @SuppressWarnings("unchecked")
    public void message(XSLProcessorContext processorContext, ElemExtensionCall extensionElement)
            throws TransformerException {

        // Initialize
        TransformerImpl transformer = processorContext.getTransformer();
        ComponentTransformerHelper transformerHelper = getTransformerHelper(processorContext);

        // Get attributes
        String messageKey = getRequiredStringProperty("key",
                "the property key needs to be provided for the message tag", processorContext, extensionElement);

        // Obtain parameters
        List<String> parameterList = new ArrayList<String>();
        Object oldParameterList = transformer.getParameter(FORMAT_HELPER_PARAMETERS);
        if (extensionElement.hasChildNodes()) {
            transformer.setParameter(FORMAT_HELPER_PARAMETERS, parameterList);
            transformer.executeChildTemplates(extensionElement, true);
            transformer.setParameter(FORMAT_HELPER_PARAMETERS,
                    oldParameterList == null ? new Boolean(false) : oldParameterList);
        }

        // Compute Results
        IRequest request = getComponentRequest(processorContext);
        if (request == null) {
            throw new TransformerException("Internal error: Invalid request passed to the layout through the "
                    + IXMLTransformer.TRANSFORMER_HELPER);
        }
        try {
            LocaleResolver localeResolver = (LocaleResolver) request.getHttpRequest()
                    .getAttribute(DispatcherServlet.LOCALE_RESOLVER_ATTRIBUTE);
            Locale locale = localeResolver.resolveLocale(request.getHttpRequest());

            String message = transformerHelper.getApplicationContext().getMessage(messageKey,
                    parameterList.toArray(), locale);

            if (oldParameterList == null) {
                serialize(processorContext, extensionElement, message, false);
            } else if (oldParameterList instanceof List) {
                ((List<String>) oldParameterList).add(message);
            }
        } catch (Exception ex) {
            throw new TransformerException("Error getting message for key=" + messageKey + ": " + ex.getMessage(),
                    ex);
        }
    }

    /**
     * Public Tag - Parameter - pass a parameter to a message
     * <p>
     * <pre><code>
     *   &lt;fmt:parameter value="<i>string literal|variable value</i>" /&gt;
     *   &lt;fmt:parameter&gt;<i>string literal</i>&lt;/param&gt;
     *   &lt;fmt:parameter&gt;<i>value-of expression</i>&lt;/param&gt;
     *   &lt;fmt:parameter&gt;<i>nested fmt:message</i>&lt;/param&gt;
     * </code></pre>
     * 
     * implicit DTD for parameter
     * 
     * <pre><code>
     * &lt;!ELEMENT toobs:parameter (PCDATA)?>
     * &lt;!ATTLIST toobs:parameter
     * value CDATA #IMPLIED&gt;
     * </code></pre>
     * 
     * Where
     * <p>
     * <ul>
     * <li>value - a string literal or xsl variable
     * </ul>
     */
    @SuppressWarnings("unchecked")
    public void parameter(XSLProcessorContext processorContext, ElemExtensionCall extensionElement)
            throws TransformerException {
        TransformerImpl transformer = processorContext.getTransformer();
        Object p = transformer.getParameter(FORMAT_HELPER_PARAMETERS);

        if (p == null || !(p instanceof List)) {
            throw new TransformerException("fmt parameter declarartion needs to be nested inside of a fmt message");
        }

        // Get attributes
        String value = getStringProperty("value", null, processorContext, extensionElement);
        if (value == null && extensionElement.hasChildNodes()) {
            Node firstChild = extensionElement.getFirstChild();
            if (firstChild instanceof ElemTextLiteral) {
                value = ((ElemTextLiteral) firstChild).getNodeValue();
            } else if (firstChild instanceof ElemValueOf) {
                XPathContext xctxt = transformer.getXPathContext();
                XPath xPath = new XPath(
                        new XRTreeFragSelectWrapper(((ElemValueOf) firstChild).getSelect().getExpression()));
                XObject var = xPath.execute(xctxt, processorContext.getContextNode(), extensionElement);
                value = var.str();
            } else if (firstChild instanceof ElemExtensionCall) {
                transformer.executeChildTemplates(extensionElement, true);
            }
        }
        if (value != null) {
            ((List<String>) p).add(value);
        }
        // this method does not execute any child templates.  No xslt instructions can be nested under it
    }
}