tiles-parent/tiles-core/src/main/java/org/apache/tiles/impl/BasicTilesContainer.java - tiles - Git at Google

 /*
  * $Id$
  *
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF 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.apache.tiles.impl;

 import java.io.IOException;
 import java.util.Deque;
 import java.util.LinkedList;
 import java.util.Map;

 import org.apache.tiles.Attribute;
 import org.apache.tiles.AttributeContext;
 import org.apache.tiles.BasicAttributeContext;
 import org.apache.tiles.Definition;
 import org.apache.tiles.TilesContainer;
 import org.apache.tiles.definition.DefinitionsFactory;
 import org.apache.tiles.definition.NoSuchDefinitionException;
 import org.apache.tiles.evaluator.AttributeEvaluator;
 import org.apache.tiles.evaluator.AttributeEvaluatorFactory;
 import org.apache.tiles.evaluator.AttributeEvaluatorFactoryAware;
 import org.apache.tiles.preparer.ViewPreparer;
 import org.apache.tiles.preparer.factory.NoSuchPreparerException;
 import org.apache.tiles.preparer.factory.PreparerFactory;
 import org.apache.tiles.request.ApplicationContext;
 import org.apache.tiles.request.Request;
 import org.apache.tiles.request.render.CannotRenderException;
 import org.apache.tiles.request.render.Renderer;
 import org.apache.tiles.request.render.RendererFactory;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 /**
  * Basic implementation of the tiles container interface.
  * In most cases, this container will be customized by
  * injecting customized services, not necessarily by
  * override the container
  *
  * @since 2.0
  * @version $Rev$ $Date$
  */
 public class BasicTilesContainer implements TilesContainer,
         AttributeEvaluatorFactoryAware {

     /**
      * Name used to store attribute context stack.
      */
     private static final String ATTRIBUTE_CONTEXT_STACK =
         "org.apache.tiles.AttributeContext.STACK";

     /**
      * Log instance for all BasicTilesContainer
      * instances.
      */
     private final Logger log = LoggerFactory
             .getLogger(BasicTilesContainer.class);

     /**
      * The Tiles application context object.
      */
     private ApplicationContext context;

     /**
      * The definitions factory.
      */
     private DefinitionsFactory definitionsFactory;

     /**
      * The preparer factory.
      */
     private PreparerFactory preparerFactory;

     /**
      * The renderer factory.
      */
     private RendererFactory rendererFactory;

     /**
      * The attribute evaluator.
      */
     private AttributeEvaluatorFactory attributeEvaluatorFactory;

     /** {@inheritDoc} */
     public AttributeContext startContext(Request request) {
         AttributeContext context = new BasicAttributeContext();
         Deque<AttributeContext>  stack = getContextStack(request);
         if (!stack.isEmpty()) {
             AttributeContext parent = stack.peek();
             context.inheritCascadedAttributes(parent);
         }
         stack.push(context);
         return context;
     }

     /** {@inheritDoc} */
     public void endContext(Request request) {
         popContext(request);
     }

     /** {@inheritDoc} */
     public void renderContext(Request request) {
         AttributeContext attributeContext = getAttributeContext(request);

         render(request, attributeContext);
     }

     /**
      * Returns the Tiles application context used by this container.
      *
      * @return the application context for this container.
      */
     public ApplicationContext getApplicationContext() {
         return context;
     }

     /**
      * Sets the Tiles application context to use.
      *
      * @param context The Tiles application context.
      */
     public void setApplicationContext(ApplicationContext context) {
         this.context = context;
     }

     /** {@inheritDoc} */
     public AttributeContext getAttributeContext(Request request) {
         AttributeContext context = getContext(request);
         if (context == null) {
             context = new BasicAttributeContext();
             pushContext(context, request);
         }
         return context;

     }

     /**
      * Returns the definitions factory.
      *
      * @return The definitions factory used by this container.
      */
     public DefinitionsFactory getDefinitionsFactory() {
         return definitionsFactory;
     }

     /**
      * Set the definitions factory. This method first ensures
      * that the container has not yet been initialized.
      *
      * @param definitionsFactory the definitions factory for this instance.
      */
     public void setDefinitionsFactory(DefinitionsFactory definitionsFactory) {
         this.definitionsFactory = definitionsFactory;
     }

     /**
      * Returns the preparer factory used by this container.
      *
      * @return return the preparerInstance factory used by this container.
      */
     public PreparerFactory getPreparerFactory() {
         return preparerFactory;
     }

     /**
      * Set the preparerInstance factory.  This method first ensures
      * that the container has not yet been initialized.
      *
      * @param preparerFactory the preparerInstance factory for this conainer.
      */
     public void setPreparerFactory(PreparerFactory preparerFactory) {
         this.preparerFactory = preparerFactory;
     }

     /**
      * Sets the renderer instance factory.
      *
      * @param rendererFactory the renderer instance factory for this container.
      * @since 2.1.0
      */
     public void setRendererFactory(RendererFactory rendererFactory) {
         this.rendererFactory = rendererFactory;
     }

     /** {@inheritDoc} */
     public void setAttributeEvaluatorFactory(
             AttributeEvaluatorFactory attributeEvaluatorFactory) {
         this.attributeEvaluatorFactory = attributeEvaluatorFactory;
     }

     /** {@inheritDoc} */
     public void prepare(String preparer, Request request) {
         prepare(request, preparer, false);
     }

     /** {@inheritDoc} */
     public void render(String definitionName, Request request) {
         log.debug("Render request received for definition '{}'", definitionName);

         Definition definition = getDefinition(definitionName, request);

         if (definition == null) {
             throw new NoSuchDefinitionException("Unable to find the definition '" + definitionName + "'");
         }

         render(definition, request);
     }

     /**
      * Renders the specified definition.
      * @param definition The definition to render.
      * @param request The request context.
      * @since 2.1.3
      */
     public void render(Definition definition, Request request) {
         AttributeContext originalContext = getAttributeContext(request);
         BasicAttributeContext subContext = new BasicAttributeContext(definition);
         subContext.inherit(originalContext);

         pushContext(subContext, request);

         try {
             render(request, subContext);
         } finally {
             popContext(request);
         }
     }

     /** {@inheritDoc} */
     public void render(Attribute attr, Request request)
         throws IOException {
         if (attr == null) {
             throw new CannotRenderException("Cannot render a null attribute");
         }

         if (attr.isPermitted(request)) {
             Renderer renderer = rendererFactory.getRenderer(attr.getRenderer());
             Object value = evaluate(attr, request);
             if (!(value instanceof String)) {
                 throw new CannotRenderException(
                         "Cannot render an attribute that is not a string, toString returns: "
                                 + value);
             }
             renderer.render((String) value, request);
         }
     }

     /** {@inheritDoc} */
     public Object evaluate(Attribute attribute, Request request) {
         AttributeEvaluator evaluator = attributeEvaluatorFactory
                 .getAttributeEvaluator(attribute);
         return evaluator.evaluate(attribute, request);
     }

     /** {@inheritDoc} */
     public boolean isValidDefinition(String definitionName, Request request) {
         try {
             Definition definition = getDefinition(definitionName, request);
             return definition != null;
         } catch (NoSuchDefinitionException nsde) {
             log.debug("Cannot find definition '{}'", definitionName);
             log.debug("Exception related to the not found definition", nsde);
             return false;
         }
     }

     /** {@inheritDoc} */
     @Override
     public Definition getDefinition(String definitionName,
             Request request) {
         Definition definition =
             definitionsFactory.getDefinition(definitionName, request);
         return definition;
     }

     /**
      * Returns the context stack.
      *
      * @param tilesContext The Tiles context object to use.
      * @return The needed stack of contexts.
      * @since 2.0.6
      */
     @SuppressWarnings("unchecked")
     protected Deque<AttributeContext> getContextStack(Request tilesContext) {
         Map<String, Object> requestScope = tilesContext.getContext("request");
         Deque<AttributeContext> contextStack = (Deque<AttributeContext>) requestScope
                 .get(ATTRIBUTE_CONTEXT_STACK);
         if (contextStack == null) {
             contextStack = new LinkedList<AttributeContext>();
             requestScope.put(ATTRIBUTE_CONTEXT_STACK, contextStack);
         }

         return contextStack;
     }

     /**
      * Pushes a context object in the stack.
      *
      * @param context The context to push.
      * @param tilesContext The Tiles context object to use.
      * @since 2.0.6
      */
     protected void pushContext(AttributeContext context,
             Request tilesContext) {
         Deque<AttributeContext> contextStack = getContextStack(tilesContext);
         contextStack.push(context);
     }

     /**
      * Pops a context object out of the stack.
      *
      * @param tilesContext The Tiles context object to use.
      * @return The popped context object.
      * @since 2.0.6
      */
     protected AttributeContext popContext(Request tilesContext) {
         Deque<AttributeContext> contextStack = getContextStack(tilesContext);
         return contextStack.pop();
     }

     /**
      * Get attribute context from request.
      *
      * @param tilesContext current Tiles application context.
      * @return BasicAttributeContext or null if context is not found.
      * @since 2.0.6
      */
     protected AttributeContext getContext(Request tilesContext) {
         Deque<AttributeContext> contextStack = getContextStack(tilesContext);
         if (!contextStack.isEmpty()) {
             return contextStack.peek();
         }
         return null;
     }

     /**
      * Execute a preparer.
      *
      * @param context The request context.
      * @param preparerName The name of the preparer.
      * @param ignoreMissing If <code>true</code> if the preparer is not found,
      * it ignores the problem.
      * @throws NoSuchPreparerException If the preparer is not found (and
      * <code>ignoreMissing</code> is not set) or if the preparer itself threw an
      * exception.
      */
     private void prepare(Request context, String preparerName, boolean ignoreMissing) {

         log.debug("Prepare request received for '{}'", preparerName);

         ViewPreparer preparer = preparerFactory.getPreparer(preparerName, context);
         if (preparer == null && ignoreMissing) {
             return;
         }

         if (preparer == null) {
             throw new NoSuchPreparerException("Preparer '" + preparerName + " not found");
         }

         AttributeContext attributeContext = getContext(context);

         preparer.execute(context, attributeContext);
     }

     /**
      * Renders the specified attribute context.
      *
      * @param request The request context.
      * @param attributeContext The context to render.
      * @throws InvalidTemplateException If the template is not valid.
      * @throws CannotRenderException If something goes wrong during rendering.
      * @since 2.1.3
      */
     protected void render(Request request,
             AttributeContext attributeContext) {

         try {
             if (attributeContext.getPreparer() != null) {
                 prepare(request, attributeContext.getPreparer(), true);
             }

             render(attributeContext.getTemplateAttribute(), request);
         } catch (IOException e) {
             throw new CannotRenderException(e.getMessage(), e);
         }
     }
 }
	/*
	* $Id$
	*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF 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.apache.tiles.impl;

	import java.io.IOException;
	import java.util.Deque;
	import java.util.LinkedList;
	import java.util.Map;

	import org.apache.tiles.Attribute;
	import org.apache.tiles.AttributeContext;
	import org.apache.tiles.BasicAttributeContext;
	import org.apache.tiles.Definition;
	import org.apache.tiles.TilesContainer;
	import org.apache.tiles.definition.DefinitionsFactory;
	import org.apache.tiles.definition.NoSuchDefinitionException;
	import org.apache.tiles.evaluator.AttributeEvaluator;
	import org.apache.tiles.evaluator.AttributeEvaluatorFactory;
	import org.apache.tiles.evaluator.AttributeEvaluatorFactoryAware;
	import org.apache.tiles.preparer.ViewPreparer;
	import org.apache.tiles.preparer.factory.NoSuchPreparerException;
	import org.apache.tiles.preparer.factory.PreparerFactory;
	import org.apache.tiles.request.ApplicationContext;
	import org.apache.tiles.request.Request;
	import org.apache.tiles.request.render.CannotRenderException;
	import org.apache.tiles.request.render.Renderer;
	import org.apache.tiles.request.render.RendererFactory;
	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;

	/**
	* Basic implementation of the tiles container interface.
	* In most cases, this container will be customized by
	* injecting customized services, not necessarily by
	* override the container
	*
	* @since 2.0
	* @version $Rev$ $Date$
	*/
	public class BasicTilesContainer implements TilesContainer,
	AttributeEvaluatorFactoryAware {

	/**
	* Name used to store attribute context stack.
	*/
	private static final String ATTRIBUTE_CONTEXT_STACK =
	"org.apache.tiles.AttributeContext.STACK";

	/**
	* Log instance for all BasicTilesContainer
	* instances.
	*/
	private final Logger log = LoggerFactory
	.getLogger(BasicTilesContainer.class);

	/**
	* The Tiles application context object.
	*/
	private ApplicationContext context;

	/**
	* The definitions factory.
	*/
	private DefinitionsFactory definitionsFactory;

	/**
	* The preparer factory.
	*/
	private PreparerFactory preparerFactory;

	/**
	* The renderer factory.
	*/
	private RendererFactory rendererFactory;

	/**
	* The attribute evaluator.
	*/
	private AttributeEvaluatorFactory attributeEvaluatorFactory;

	/** {@inheritDoc} */
	public AttributeContext startContext(Request request) {
	AttributeContext context = new BasicAttributeContext();
	Deque<AttributeContext> stack = getContextStack(request);
	if (!stack.isEmpty()) {
	AttributeContext parent = stack.peek();
	context.inheritCascadedAttributes(parent);
	}
	stack.push(context);
	return context;
	}

	/** {@inheritDoc} */
	public void endContext(Request request) {
	popContext(request);
	}

	/** {@inheritDoc} */
	public void renderContext(Request request) {
	AttributeContext attributeContext = getAttributeContext(request);

	render(request, attributeContext);
	}

	/**
	* Returns the Tiles application context used by this container.
	*
	* @return the application context for this container.
	*/
	public ApplicationContext getApplicationContext() {
	return context;
	}

	/**
	* Sets the Tiles application context to use.
	*
	* @param context The Tiles application context.
	*/
	public void setApplicationContext(ApplicationContext context) {
	this.context = context;
	}

	/** {@inheritDoc} */
	public AttributeContext getAttributeContext(Request request) {
	AttributeContext context = getContext(request);
	if (context == null) {
	context = new BasicAttributeContext();
	pushContext(context, request);
	}
	return context;

	}

	/**
	* Returns the definitions factory.
	*
	* @return The definitions factory used by this container.
	*/
	public DefinitionsFactory getDefinitionsFactory() {
	return definitionsFactory;
	}

	/**
	* Set the definitions factory. This method first ensures
	* that the container has not yet been initialized.
	*
	* @param definitionsFactory the definitions factory for this instance.
	*/
	public void setDefinitionsFactory(DefinitionsFactory definitionsFactory) {
	this.definitionsFactory = definitionsFactory;
	}

	/**
	* Returns the preparer factory used by this container.
	*
	* @return return the preparerInstance factory used by this container.
	*/
	public PreparerFactory getPreparerFactory() {
	return preparerFactory;
	}

	/**
	* Set the preparerInstance factory. This method first ensures
	* that the container has not yet been initialized.
	*
	* @param preparerFactory the preparerInstance factory for this conainer.
	*/
	public void setPreparerFactory(PreparerFactory preparerFactory) {
	this.preparerFactory = preparerFactory;
	}

	/**
	* Sets the renderer instance factory.
	*
	* @param rendererFactory the renderer instance factory for this container.
	* @since 2.1.0
	*/
	public void setRendererFactory(RendererFactory rendererFactory) {
	this.rendererFactory = rendererFactory;
	}

	/** {@inheritDoc} */
	public void setAttributeEvaluatorFactory(
	AttributeEvaluatorFactory attributeEvaluatorFactory) {
	this.attributeEvaluatorFactory = attributeEvaluatorFactory;
	}

	/** {@inheritDoc} */
	public void prepare(String preparer, Request request) {
	prepare(request, preparer, false);
	}

	/** {@inheritDoc} */
	public void render(String definitionName, Request request) {
	log.debug("Render request received for definition '{}'", definitionName);

	Definition definition = getDefinition(definitionName, request);

	if (definition == null) {
	throw new NoSuchDefinitionException("Unable to find the definition '" + definitionName + "'");
	}

	render(definition, request);
	}

	/**
	* Renders the specified definition.
	* @param definition The definition to render.
	* @param request The request context.
	* @since 2.1.3
	*/
	public void render(Definition definition, Request request) {
	AttributeContext originalContext = getAttributeContext(request);
	BasicAttributeContext subContext = new BasicAttributeContext(definition);
	subContext.inherit(originalContext);

	pushContext(subContext, request);

	try {
	render(request, subContext);
	} finally {
	popContext(request);
	}
	}

	/** {@inheritDoc} */
	public void render(Attribute attr, Request request)
	throws IOException {
	if (attr == null) {
	throw new CannotRenderException("Cannot render a null attribute");
	}

	if (attr.isPermitted(request)) {
	Renderer renderer = rendererFactory.getRenderer(attr.getRenderer());
	Object value = evaluate(attr, request);
	if (!(value instanceof String)) {
	throw new CannotRenderException(
	"Cannot render an attribute that is not a string, toString returns: "
	+ value);
	}
	renderer.render((String) value, request);
	}
	}

	/** {@inheritDoc} */
	public Object evaluate(Attribute attribute, Request request) {
	AttributeEvaluator evaluator = attributeEvaluatorFactory
	.getAttributeEvaluator(attribute);
	return evaluator.evaluate(attribute, request);
	}

	/** {@inheritDoc} */
	public boolean isValidDefinition(String definitionName, Request request) {
	try {
	Definition definition = getDefinition(definitionName, request);
	return definition != null;
	} catch (NoSuchDefinitionException nsde) {
	log.debug("Cannot find definition '{}'", definitionName);
	log.debug("Exception related to the not found definition", nsde);
	return false;
	}
	}

	/** {@inheritDoc} */
	@Override
	public Definition getDefinition(String definitionName,
	Request request) {
	Definition definition =
	definitionsFactory.getDefinition(definitionName, request);
	return definition;
	}

	/**
	* Returns the context stack.
	*
	* @param tilesContext The Tiles context object to use.
	* @return The needed stack of contexts.
	* @since 2.0.6
	*/
	@SuppressWarnings("unchecked")
	protected Deque<AttributeContext> getContextStack(Request tilesContext) {
	Map<String, Object> requestScope = tilesContext.getContext("request");
	Deque<AttributeContext> contextStack = (Deque<AttributeContext>) requestScope
	.get(ATTRIBUTE_CONTEXT_STACK);
	if (contextStack == null) {
	contextStack = new LinkedList<AttributeContext>();
	requestScope.put(ATTRIBUTE_CONTEXT_STACK, contextStack);
	}

	return contextStack;
	}

	/**
	* Pushes a context object in the stack.
	*
	* @param context The context to push.
	* @param tilesContext The Tiles context object to use.
	* @since 2.0.6
	*/
	protected void pushContext(AttributeContext context,
	Request tilesContext) {
	Deque<AttributeContext> contextStack = getContextStack(tilesContext);
	contextStack.push(context);
	}

	/**
	* Pops a context object out of the stack.
	*
	* @param tilesContext The Tiles context object to use.
	* @return The popped context object.
	* @since 2.0.6
	*/
	protected AttributeContext popContext(Request tilesContext) {
	Deque<AttributeContext> contextStack = getContextStack(tilesContext);
	return contextStack.pop();
	}

	/**
	* Get attribute context from request.
	*
	* @param tilesContext current Tiles application context.
	* @return BasicAttributeContext or null if context is not found.
	* @since 2.0.6
	*/
	protected AttributeContext getContext(Request tilesContext) {
	Deque<AttributeContext> contextStack = getContextStack(tilesContext);
	if (!contextStack.isEmpty()) {
	return contextStack.peek();
	}
	return null;
	}

	/**
	* Execute a preparer.
	*
	* @param context The request context.
	* @param preparerName The name of the preparer.
	* @param ignoreMissing If <code>true</code> if the preparer is not found,
	* it ignores the problem.
	* @throws NoSuchPreparerException If the preparer is not found (and
	* <code>ignoreMissing</code> is not set) or if the preparer itself threw an
	* exception.
	*/
	private void prepare(Request context, String preparerName, boolean ignoreMissing) {

	log.debug("Prepare request received for '{}'", preparerName);

	ViewPreparer preparer = preparerFactory.getPreparer(preparerName, context);
	if (preparer == null && ignoreMissing) {
	return;
	}

	if (preparer == null) {
	throw new NoSuchPreparerException("Preparer '" + preparerName + " not found");
	}

	AttributeContext attributeContext = getContext(context);

	preparer.execute(context, attributeContext);
	}

	/**
	* Renders the specified attribute context.
	*
	* @param request The request context.
	* @param attributeContext The context to render.
	* @throws InvalidTemplateException If the template is not valid.
	* @throws CannotRenderException If something goes wrong during rendering.
	* @since 2.1.3
	*/
	protected void render(Request request,
	AttributeContext attributeContext) {

	try {
	if (attributeContext.getPreparer() != null) {
	prepare(request, attributeContext.getPreparer(), true);
	}

	render(attributeContext.getTemplateAttribute(), request);
	} catch (IOException e) {
	throw new CannotRenderException(e.getMessage(), e);
	}
	}
	}