/java/src/org/jpublish/page/PageInstance.java

/*

 * Copyright 2004-2007 the original author or authors.

 *

 * 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 org.jpublish.page;



import com.anthonyeden.lib.config.Configuration;

import com.anthonyeden.lib.config.ConfigurationException;

import com.anthonyeden.lib.config.XMLConfiguration;

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

import org.jpublish.JPublishContext;

import org.jpublish.SiteContext;

import org.jpublish.action.Action;

import org.jpublish.action.ActionWrapper;



import java.io.InputStream;

import java.util.*;



/**

 * A representation of a single web page.  A page is defined by an XML

 * document in the pages directory.  Each page has a template associated

 * with the page and can have 0 or more actions attached to the page.

 * <p/>

 * <p>Actions attached to a page will be triggered each time the page

 * is requested.  Actions will be triggered in the order that they are

 * listed within the Page's configuration.</p>

 * <p/>

 * <p>There should only be a single PageInstance in memory for each path.

 * Each PageInstance is actually wrapped in a Page class which provides

 * request-specific features.

 *

 * @author Anthony Eden

 * @author <a href="mailto:florin.patrascu@gmail.com">Florin T.PATRASCU</a>

 */



public class PageInstance {



    private static Log log = LogFactory.getLog(PageInstance.class);



    private SiteContext siteContext;

    private List pageActions;

    private String path;

    private String pageName;

    private String pageType;

    private String templateName;

    private Map properties;

    private Configuration configuration = null;



    /**

     * Construct a new Page for the given path.  The name of the page is

     * the last part of the path (i.e. the file component) without the

     * dot ending.  The page type is the dot-ending.

     *

     * @param siteContext The SiteContext

     * @param path        The request path

     * @param pageName    The name of the page

     * @param pageType    The page type

     */



    public PageInstance(SiteContext siteContext, String path, String pageName, String pageType) {

        this.siteContext = siteContext;

        this.path = path;

        this.pageName = pageName;

        this.pageType = pageType;

        this.pageActions = new ArrayList();

        this.templateName = siteContext.getDefaultTemplate();

        this.properties = new HashMap();

    }



    /**

     * Get the request path.

     *

     * @return The request path

     */



    public String getPath() {

        return path;

    }



    /**

     * Get the page name.

     *

     * @return The page name

     */



    public String getPageName() {

        return pageName;

    }



    /**

     * Get the page type.

     *

     * @return The page type

     */



    public String getPageType() {

        return pageType;

    }



    /**

     * Return the page title.  Initially the page title is extracted from

     * the page's definition document, however it can be set programtically

     * at runtime.

     * <p/>

     * <p>This method is deprecated.  Use getProperty("title") instead and

     * include a property named title in the page configuration file.  The

     * old &lt;title&gt; element and this method will be removed for the

     * 1.0 release.

     *

     * @return The page title

     * @deprecated Use getProperty("title") instead

     */



    public String getTitle() {

        String title = getProperty("Title");

        if (title == null) {

            title = getProperty("title");

        }

        return title;

    }



    /**

     * Set the title.  This will temporarily alter the page's title.

     * <p/>

     * <p>This method is deprecated.  The old &lt;title&gt; element

     * and this method will be removed for the 1.0 release.

     *

     * @param title The page title

     * @deprecated

     */



    public void setTitle(String title) {

        if (title != null) {

            if (log.isDebugEnabled())

                log.debug("setTitle(" + title + ")");

            setProperty("title", title, null);

        }

    }



    /**

     * Get the full template file name, with the .suffix attached.

     *

     * @return The full template name

     */



    public String getFullTemplateName() {

        return templateName + "." + pageType;

    }



    /**

     * Get the template name.  If the template name is not specified in the

     * page configuration then the default template as specified in the

     * SiteContext will be used.

     *

     * @return The template name

     */



    public String getTemplateName() {

        return templateName;

    }



    /**

     * Set the template name.  Invoking this method with a null value will

     * reset the template to the default template as specified in the

     * SiteContext.

     *

     * @param templateName The new template name or null to reset

     */



    public synchronized void setTemplateName(String templateName) {

        if (log.isDebugEnabled())

            log.debug("setTemplateName(" + templateName + ")");

        if (templateName == null) {

            templateName = siteContext.getDefaultTemplate();

            if (log.isDebugEnabled())

                log.debug("Using default template: " + templateName);

        }

        this.templateName = templateName;

    }



    /**

     * Get a List of page actions.  To add an action to the page just add

     * the action to this List.  Page actions are triggered each time the

     * page is requested.

     *

     * @return A List of page actions

     */



    public List getPageActions() {

        return pageActions;

    }



    /**

     * Get the named page property using the default Locale.  If the

     * property is not found then return null.

     *

     * @param name The property name

     * @return The value or null

     */



    public String getProperty(String name) {

        return getProperty(name, Locale.getDefault());

    }



    /**

     * Get the Locale-specific value for the given named property.  If

     * the property is not found then return null.  This method will try to

     * find the most suitable locale by searching the property values in the

     * following manner:

     * <p/>

     * <p/>

     * language + "_" + country + "_" + variant<br>

     * language + "_" + country<br>

     * langauge<br>

     * ""

     * </p>

     *

     * @param name   The property name

     * @param locale The locale

     * @return The value

     */



    public String getProperty(String name, Locale locale) {

        if (log.isDebugEnabled())

            log.debug("Get property [name=" + name + ",locale=" + locale + "]");

        PageProperty property = (PageProperty) properties.get(name);

        if (property != null) {

            return property.getValue(locale);

        } else {

            return null;

        }

    }



    /**

     * Get the named property.  This method is equivilent to the

     * <code>getProperty(name)</code> method.  This method is provided

     * as a convenience to view code.

     *

     * @param name The property name

     * @return The value

     */



    public String get(String name) {

        return getProperty(name);

    }



    /**

     * Execute the page actions using the given context.

     *

     * @param context The current context

     * @return A redirection value or null if there is no redirection

     * @throws Exception Any Exception which occurs while executing the action

     */



    public String executeActions(JPublishContext context) throws Exception {

        Iterator pageActions = getPageActions().iterator();

        while (pageActions.hasNext()) {

            ((ActionWrapper) pageActions.next()).execute(context);



            String redirect = (String) context.get("redirect");

            if (redirect != null) {

                return redirect;

            }

        }

        return null;

    }



    /**

     * Load the page configuration from the page's XML stream.

     *

     * @param in The InputStream

     * @throws Exception Any exception

     */



    public synchronized void load(InputStream in) throws Exception {

        if (log.isDebugEnabled())

            log.debug("Loading page: " + path);



        Configuration configuration = new XMLConfiguration(in);

        loadConfiguration(configuration);

    }



    /**

     * Load the page configuration from the given Configuration object.

     *

     * @param configuration The Configuration object

     * @throws ConfigurationException

     */



    public synchronized void loadConfiguration(Configuration configuration) throws ConfigurationException {



        if (log.isDebugEnabled())

            log.debug("Loading page: " + path);



        this.configuration = configuration;

        setTitle(configuration.getChildValue("title"));

        setTemplateName(configuration.getChildValue("template"));



        // load page actions

        if (log.isDebugEnabled())

            log.debug("Looping through page-action elements.");



        Iterator pageActionElements = configuration.getChildren("page-action").iterator();

        while (pageActionElements.hasNext()) {

            Configuration pageActionElement = (Configuration) pageActionElements.next();

            String name = pageActionElement.getAttribute("name");



            if (name == null) {

                throw new ConfigurationException("Error configuring page-action.");

            }



            Action action = siteContext.getActionManager().findAction(name);

            if (action == null) {

                throw new ConfigurationException("Action " + name + " not defined");

            }



            pageActions.add(new ActionWrapper(action, pageActionElement));

        }



        // load page properties

        if (log.isDebugEnabled())

            log.debug("Loading page properties");



        Iterator propertyElements = configuration.getChildren("property").iterator();

        String value = null;



        while (propertyElements.hasNext()) {

            Configuration propertyElement = (Configuration) propertyElements.next();

            value = propertyElement.getAttribute("value");

            setProperty(

                    propertyElement.getAttribute("name"),

                    value == null ? propertyElement.getValue() : value, propertyElement.getAttribute("locale"));

        }

    }



    /**

     * Set the property value.

     *

     * @param name   The property name

     * @param value  The value

     * @param locale The locale String or null

     */



    public void setProperty(String name, String value, String locale) {

        if (log.isDebugEnabled())

            log.debug("setProperty() [name=" + name + ",value=" + value +

                    ",locale=" + locale);

        PageProperty property = (PageProperty) properties.get(name);

        if (property == null) {

            // named property not in property map

            property = new PageProperty(name);

            properties.put(name, property);

        }

        property.setValue(value, locale);

    }



    /**

     * expose a readOnly view containing the current page instance properties

     *

     * @return a readonly view to properties [Florin]

     */

    public Map getProperties() {

        Map readOnlyProperties = null;



        if (properties != null && !properties.isEmpty())

            readOnlyProperties = Collections.unmodifiableMap(properties);



        return readOnlyProperties;

    }



    /**

     * offers access to the page configuration

     *

     * @return the page configuration

     */

    public Configuration getConfiguration() {

        return configuration;

    }



}