com.ocpsoft.pretty.faces.config.dynaview.DynaviewEngine.java Source code

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Here is the source code for com.ocpsoft.pretty.faces.config.dynaview.DynaviewEngine.java

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/*
 * Copyright 2010 Lincoln Baxter, III
 * 
 * Licensed 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 com.ocpsoft.pretty.faces.config.dynaview;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.faces.context.FacesContext;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.ocpsoft.pretty.PrettyContext;
import com.ocpsoft.pretty.PrettyException;
import com.ocpsoft.pretty.faces.application.PrettyRedirector;
import com.ocpsoft.pretty.faces.beans.ExtractedValuesURLBuilder;
import com.ocpsoft.pretty.faces.config.mapping.UrlMapping;
import com.ocpsoft.pretty.faces.util.FacesElUtils;

public class DynaviewEngine {
    public static final String DYNAVIEW = "com.ocpsoft.dynaView";

    private static final Log log = LogFactory.getLog(DynaviewEngine.class);
    private static FacesElUtils elUtils = new FacesElUtils();

    /**
     * Given the string value of the Faces Servlet mapping, return a string that is guaranteed to match when a servlet
     * forward is issued. It doesn't matter which FacesServlet we get to, as long as we get to one.
     */
    public String buildDynaViewId(final String facesServletMapping) {
        StringBuffer result = new StringBuffer();

        Map<Pattern, String> patterns = new HashMap<Pattern, String>();

        Pattern pathMapping = Pattern.compile("^(/.*/)\\*$");
        Pattern extensionMapping = Pattern.compile("^\\*(\\..*)$");
        Pattern defaultMapping = Pattern.compile("^/$");

        patterns.put(pathMapping, "$1" + DYNAVIEW + ".jsf");
        patterns.put(extensionMapping, "/" + DYNAVIEW + "$1");
        patterns.put(defaultMapping, "/" + DYNAVIEW + ".jsf");

        boolean matched = false;
        Iterator<Pattern> iterator = patterns.keySet().iterator();
        while ((matched == false) && iterator.hasNext()) {
            Pattern p = iterator.next();
            Matcher m = p.matcher(facesServletMapping);
            if (m.matches()) {
                String replacement = patterns.get(p);
                m.appendReplacement(result, replacement);
                matched = true;
            }
        }

        if (matched == false) {
            // This is an exact url-mapping, use it.
            result.append(facesServletMapping);
        }

        return result.toString();
    }

    /**
     * Handle DynaView processing. This method will end the Faces life-cycle.
     */
    public void processDynaView(final PrettyContext prettyContext, final FacesContext facesContext) {
        log.trace("Requesting DynaView processing for: " + prettyContext.getRequestURL());
        String viewId = "";
        try {
            viewId = prettyContext.getCurrentViewId();
            log.trace("Invoking DynaView method: " + viewId);
            Object result = computeDynaViewId(facesContext);
            if (result instanceof String) {
                viewId = (String) result;
                log.trace("Forwarding to DynaView: " + viewId);
                prettyContext.setDynaviewProcessed(true);
                facesContext.getExternalContext().dispatch(viewId);
                facesContext.responseComplete();
            }
        } catch (Exception e) {
            log.error("Failed to process dynaview", e);
            PrettyRedirector prettyRedirector = new PrettyRedirector();
            prettyRedirector.send404(facesContext);
            throw new PrettyException("Could not forward to view: " + viewId + "", e);
        }
    }

    /**
     * Calculate the Faces ViewId to which this request URI resolves. This method will recursively call any dynamic
     * mapping viewId functions as needed until a String viewId is returned, or supplied by a static mapping.
     * <p>
     * This phase does not support FacesNavigation or PrettyRedirecting. Its SOLE purpose is to resolve a viewId.
     * <p>
     * <i><b>Note:</b> Precondition - parameter injection must take place before this</i>
     * <p>
     * <i>Postcondition - currentViewId is set to computed View Id</i>
     * 
     * @param facesContext2
     * 
     * @return JSF viewID to which this request resolves.
     */
    public String computeDynaViewId(final FacesContext facesContext) {
        PrettyContext context = PrettyContext.getCurrentInstance(facesContext);
        UrlMapping urlMapping = context.getCurrentMapping();

        return calculateDynaviewId(facesContext, urlMapping);
    }

    public String calculateDynaviewId(final FacesContext facesContext, UrlMapping urlMapping) {
        String result = "";
        if (urlMapping != null) {
            PrettyContext context = PrettyContext.getCurrentInstance(facesContext);

            String viewId = urlMapping.getViewId();
            if (viewId == null) {
                viewId = "";
            }
            while (elUtils.isEl(viewId)) {
                Object viewResult = elUtils.invokeMethod(facesContext, viewId);
                if (viewResult == null) {
                    viewId = "";
                    break;
                } else {
                    viewId = viewResult.toString();
                }

                if (context.getConfig().isMappingId(viewId)) {
                    urlMapping = context.getConfig().getMappingById(viewId);
                    viewId = urlMapping.getViewId();
                    ExtractedValuesURLBuilder builder = new ExtractedValuesURLBuilder();
                    result = context.getContextPath() + builder.buildURL(urlMapping).encode()
                            + builder.buildQueryString(urlMapping);
                } else {
                    result = viewId;
                }
            }
            if ("".equals(viewId)) {
                log.debug("ViewId for mapping with id <" + urlMapping.getId() + "> was blank");
            }
            result = context.stripContextPath(result);
        }
        return result;
    }
}