// Copyright 2009, 2010, 2011 The Apache Software Foundation
//
// 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.apache.tapestry5.internal.pageload;
import java.util.Collections;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import org.apache.tapestry5.Binding;
import org.apache.tapestry5.BindingConstants;
import org.apache.tapestry5.ComponentResources;
import org.apache.tapestry5.MarkupWriter;
import org.apache.tapestry5.internal.InternalComponentResources;
import org.apache.tapestry5.internal.InternalConstants;
import org.apache.tapestry5.internal.bindings.LiteralBinding;
import org.apache.tapestry5.internal.parser.AttributeToken;
import org.apache.tapestry5.internal.parser.BlockToken;
import org.apache.tapestry5.internal.parser.CDATAToken;
import org.apache.tapestry5.internal.parser.CommentToken;
import org.apache.tapestry5.internal.parser.ComponentTemplate;
import org.apache.tapestry5.internal.parser.DTDToken;
import org.apache.tapestry5.internal.parser.DefineNamespacePrefixToken;
import org.apache.tapestry5.internal.parser.ExpansionToken;
import org.apache.tapestry5.internal.parser.ExtensionPointToken;
import org.apache.tapestry5.internal.parser.ParameterToken;
import org.apache.tapestry5.internal.parser.StartComponentToken;
import org.apache.tapestry5.internal.parser.StartElementToken;
import org.apache.tapestry5.internal.parser.TemplateToken;
import org.apache.tapestry5.internal.parser.TextToken;
import org.apache.tapestry5.internal.parser.TokenType;
import org.apache.tapestry5.internal.services.ComponentInstantiatorSource;
import org.apache.tapestry5.internal.services.ComponentTemplateSource;
import org.apache.tapestry5.internal.services.Instantiator;
import org.apache.tapestry5.internal.services.PageElementFactory;
import org.apache.tapestry5.internal.services.PageLoader;
import org.apache.tapestry5.internal.services.PersistentFieldManager;
import org.apache.tapestry5.internal.services.StringInterner;
import org.apache.tapestry5.internal.structure.BlockImpl;
import org.apache.tapestry5.internal.structure.CommentPageElement;
import org.apache.tapestry5.internal.structure.ComponentPageElement;
import org.apache.tapestry5.internal.structure.ComponentPageElementResources;
import org.apache.tapestry5.internal.structure.ComponentPageElementResourcesSource;
import org.apache.tapestry5.internal.structure.DTDPageElement;
import org.apache.tapestry5.internal.structure.Page;
import org.apache.tapestry5.internal.structure.PageImpl;
import org.apache.tapestry5.internal.structure.StartElementPageElement;
import org.apache.tapestry5.internal.structure.TextPageElement;
import org.apache.tapestry5.ioc.Invokable;
import org.apache.tapestry5.ioc.Location;
import org.apache.tapestry5.ioc.OperationTracker;
import org.apache.tapestry5.ioc.internal.util.CollectionFactory;
import org.apache.tapestry5.ioc.internal.util.InternalUtils;
import org.apache.tapestry5.ioc.internal.util.TapestryException;
import org.apache.tapestry5.ioc.services.PerthreadManager;
import org.apache.tapestry5.ioc.services.SymbolSource;
import org.apache.tapestry5.ioc.util.Stack;
import org.apache.tapestry5.model.ComponentModel;
import org.apache.tapestry5.model.EmbeddedComponentModel;
import org.apache.tapestry5.runtime.RenderCommand;
import org.apache.tapestry5.runtime.RenderQueue;
import org.apache.tapestry5.services.ComponentClassResolver;
import org.apache.tapestry5.services.InvalidationListener;
import org.apache.tapestry5.services.Request;
import org.apache.tapestry5.services.pageload.ComponentResourceSelector;
/**
* There's still a lot of room to beef up {@link org.apache.tapestry5.internal.pageload.ComponentAssembler} and
* {@link org.apache.tapestry5.internal.pageload.EmbeddedComponentAssembler} to perform more static analysis, but
* that may no longer be necessary, given the switch to shared (non-pooled) pages in 5.2.
* <p/>
* Loading a page involves a recursive process of creating
* {@link org.apache.tapestry5.internal.pageload.ComponentAssembler}s: for the root component, then down the tree for
* each embedded component. A ComponentAssembler is largely a collection of
* {@link org.apache.tapestry5.internal.pageload.PageAssemblyAction}s. Once created, a ComponentAssembler can quickly
* assemble any number of component instances. All of the expensive logic, such as fitting template tokens together and
* matching parameters to bindings, is done as part of the one-time construction of the ComponentAssembler. The end
* result removes a huge amount of computational redundancy that was present in Tapestry 5.0, but to understand this,
* you need to split your mind into two phases: construction (of the ComponentAssemblers) and assembly.
* <p/>
* And truly, <em>This is the Tapestry Heart, This is the Tapestry Soul...</em>
*/
public class PageLoaderImpl implements PageLoader, InvalidationListener, ComponentAssemblerSource
{
private static final class Key
{
private final String className;
private final ComponentResourceSelector selector;
private Key(String className, ComponentResourceSelector selector)
{
this.className = className;
this.selector = selector;
}
@Override
public boolean equals(Object o)
{
if (this == o)
return true;
if (o == null || getClass() != o.getClass())
return false;
Key key = (Key) o;
return className.equals(key.className) && selector.equals(key.selector);
}
@Override
public int hashCode()
{
return 31 * className.hashCode() + selector.hashCode();
}
}
private static final PageAssemblyAction POP_EMBEDDED_COMPONENT_ACTION = new PageAssemblyAction()
{
public void execute(PageAssembly pageAssembly)
{
pageAssembly.createdElement.pop();
pageAssembly.bodyElement.pop();
pageAssembly.embeddedAssembler.pop();
}
};
private static final RenderCommand END_ELEMENT = new RenderCommand()
{
public void render(MarkupWriter writer, RenderQueue queue)
{
writer.end();
}
@Override
public String toString()
{
return "End";
}
};
private final Map<Key, ComponentAssembler> cache = CollectionFactory.newConcurrentMap();
private final ComponentInstantiatorSource instantiatorSource;
private final ComponentTemplateSource templateSource;
private final PageElementFactory elementFactory;
private final ComponentPageElementResourcesSource resourcesSource;
private final ComponentClassResolver componentClassResolver;
private final PersistentFieldManager persistentFieldManager;
private final StringInterner interner;
private final OperationTracker tracker;
private final PerthreadManager perThreadManager;
private final Request request;
private final SymbolSource symbolSource;
public PageLoaderImpl(ComponentInstantiatorSource instantiatorSource, ComponentTemplateSource templateSource,
PageElementFactory elementFactory, ComponentPageElementResourcesSource resourcesSource,
ComponentClassResolver componentClassResolver, PersistentFieldManager persistentFieldManager,
StringInterner interner, OperationTracker tracker, PerthreadManager perThreadManager, Request request,
SymbolSource symbolSource)
{
this.instantiatorSource = instantiatorSource;
this.templateSource = templateSource;
this.elementFactory = elementFactory;
this.resourcesSource = resourcesSource;
this.componentClassResolver = componentClassResolver;
this.persistentFieldManager = persistentFieldManager;
this.interner = interner;
this.tracker = tracker;
this.perThreadManager = perThreadManager;
this.request = request;
this.symbolSource = symbolSource;
}
public void objectWasInvalidated()
{
cache.clear();
}
public Page loadPage(final String logicalPageName, final ComponentResourceSelector selector)
{
final String pageClassName = componentClassResolver.resolvePageNameToClassName(logicalPageName);
return tracker.invoke("Constructing instance of page class " + pageClassName, new Invokable<Page>()
{
public Page invoke()
{
Page page = new PageImpl(logicalPageName, selector, persistentFieldManager, perThreadManager);
ComponentAssembler assembler = getAssembler(pageClassName, selector);
ComponentPageElement rootElement = assembler.assembleRootComponent(page);
page.setRootElement(rootElement);
// The page is *loaded* before it is attached to the request.
// This is to help ensure that no client-specific information leaks
// into the page's default state.
page.loaded();
return page;
}
});
}
public ComponentAssembler getAssembler(String className, ComponentResourceSelector selector)
{
Key key = new Key(className, selector);
ComponentAssembler result = cache.get(key);
if (result == null)
{
// There's a window here where two threads may create the same assembler simultaneously;
// the extra assembler will be discarded.
result = createAssembler(className, selector);
cache.put(key, result);
}
return result;
}
private ComponentAssembler createAssembler(final String className, final ComponentResourceSelector selector)
{
return tracker.invoke("Creating ComponentAssembler for " + className, new Invokable<ComponentAssembler>()
{
public ComponentAssembler invoke()
{
Instantiator instantiator = instantiatorSource.getInstantiator(className);
ComponentModel componentModel = instantiator.getModel();
ComponentTemplate template = templateSource.getTemplate(componentModel, selector);
ComponentPageElementResources resources = resourcesSource.get(selector);
ComponentAssembler assembler = new ComponentAssemblerImpl(PageLoaderImpl.this, instantiatorSource,
componentClassResolver, instantiator, resources, tracker, request, symbolSource);
// "Program" the assembler by adding actions to it. The actions interact with a
// PageAssembly object (a fresh one for each new page being created).
programAssembler(assembler, template);
return assembler;
}
});
}
/**
* "Programs" the assembler by analyzing the component, its mixins and its embedded components (both in the template
* and in the Java class), adding new PageAssemblyActions.
*/
private void programAssembler(ComponentAssembler assembler, ComponentTemplate template)
{
TokenStream stream = createTokenStream(assembler, template);
AssemblerContext context = new AssemblerContext(assembler, stream);
if (template.isMissing())
{
// Pretend the template has a single <t:body> element.
body(context);
return;
}
while (context.more())
{
processTemplateToken(context);
}
context.flushComposable();
}
/**
* Creates the TokenStream by pre-processing the templates, looking for
* {@link org.apache.tapestry5.internal.parser.ExtensionPointToken}s
* and replacing them with appropriate overrides. Also validates that all embedded ids are accounted for.
*/
private TokenStream createTokenStream(ComponentAssembler assembler, ComponentTemplate template)
{
List<TemplateToken> tokens = CollectionFactory.newList();
Stack<TemplateToken> queue = CollectionFactory.newStack();
List<ComponentTemplate> overrideSearch = buildOverrideSearch(assembler, template);
// The base template is the first non-extension template upwards in the hierarchy
// from this component.
ComponentTemplate baseTemplate = getLast(overrideSearch);
pushAll(queue, baseTemplate.getTokens());
while (!queue.isEmpty())
{
TemplateToken token = queue.pop();
// When an ExtensionPoint is found, it is replaced with the tokens of its override.
if (token.getTokenType().equals(TokenType.EXTENSION_POINT))
{
ExtensionPointToken extensionPointToken = (ExtensionPointToken) token;
queueOverrideTokensForExtensionPoint(extensionPointToken, queue, overrideSearch);
}
else
{
tokens.add(token);
}
}
// Build up a map of component ids to locations
Collections.reverse(overrideSearch);
Map<String, Location> componentIds = CollectionFactory.newCaseInsensitiveMap();
for (ComponentTemplate ct : overrideSearch)
{
componentIds.putAll(ct.getComponentIds());
}
// Validate that every emebedded component id in the template (or inherited from an extended template)
// is accounted for.
assembler.validateEmbeddedIds(componentIds, template.getResource());
return new TokenStreamImpl(tokens);
}
private static <T> T getLast(List<T> list)
{
int count = list.size();
return list.get(count - 1);
}
private void queueOverrideTokensForExtensionPoint(ExtensionPointToken extensionPointToken,
Stack<TemplateToken> queue, List<ComponentTemplate> overrideSearch)
{
String extensionPointId = extensionPointToken.getExtensionPointId();
// Work up from the component, through its base classes, towards the last non-extension template.
for (ComponentTemplate t : overrideSearch)
{
List<TemplateToken> tokens = t.getExtensionPointTokens(extensionPointId);
if (tokens != null)
{
pushAll(queue, tokens);
return;
}
}
// Sanity check: since an extension point defines its own default, it's going to be hard to
// not find an override, somewhere, for it.
throw new TapestryException(PageloadMessages.couldNotFindOverride(extensionPointId),
extensionPointToken.getLocation(), null);
}
private List<ComponentTemplate> buildOverrideSearch(ComponentAssembler assembler, ComponentTemplate template)
{
List<ComponentTemplate> result = CollectionFactory.newList();
result.add(template);
ComponentModel model = assembler.getModel();
ComponentTemplate lastTemplate = template;
while (lastTemplate.isExtension())
{
ComponentModel parentModel = model.getParentModel();
if (parentModel == null) { throw new RuntimeException(PageloadMessages.noParentForExtension(model)); }
ComponentTemplate parentTemplate = templateSource.getTemplate(parentModel, assembler.getSelector());
result.add(parentTemplate);
lastTemplate = parentTemplate;
model = parentModel;
}
return result;
}
/**
* Push all the tokens onto the stack, in reverse order, so that the last token is deepest and the first token is
* most shallow (first to come off the queue).
*/
private void pushAll(Stack<TemplateToken> queue, List<TemplateToken> tokens)
{
for (int i = tokens.size() - 1; i >= 0; i--)
queue.push(tokens.get(i));
}
private void processTemplateToken(AssemblerContext context)
{
// These tokens can appear at the top level, or at lower levels (this method is invoked
// from token-processing loops inside element(), component(), etc.
switch (context.peekType())
{
case TEXT:
text(context);
break;
case EXPANSION:
expansion(context);
break;
case BODY:
context.next();
body(context);
break;
case START_ELEMENT:
// Will consume past matching end token
element(context);
break;
case START_COMPONENT:
// Will consume past matching end token
component(context);
break;
// ATTRIBUTE and END_ELEMENT can't happen at the top level, they're
// handled at a lower level. (inside element(), component(), etc.)
case COMMENT:
comment(context);
break;
case BLOCK:
// Will consume past matching end token
block(context);
break;
case PARAMETER:
// Will consume past the matching end token
parameter(context);
break;
case DTD:
dtd(context);
break;
case DEFINE_NAMESPACE_PREFIX:
defineNamespacePrefix(context);
break;
case CDATA:
cdata(context);
break;
default:
throw new IllegalStateException(PageloadMessages.tokenNotImplemented(context.peekType()));
}
}
private void cdata(AssemblerContext context)
{
final CDATAToken token = context.next(CDATAToken.class);
RenderCommand command = new RenderCommand()
{
public void render(MarkupWriter writer, RenderQueue queue)
{
writer.cdata(token.getContent());
}
@Override
public String toString()
{
return String.format("CDATA[%s]", token.getLocation());
}
};
context.addComposable(command);
}
private void defineNamespacePrefix(AssemblerContext context)
{
final DefineNamespacePrefixToken token = context.next(DefineNamespacePrefixToken.class);
RenderCommand command = new RenderCommand()
{
public void render(MarkupWriter writer, RenderQueue queue)
{
writer.defineNamespace(token.getNamespaceURI(), token.getNamespacePrefix());
}
@Override
public String toString()
{
return String.format("DefineNamespace[%s %s]", token.getNamespacePrefix(), token.getNamespaceURI());
}
};
context.addComposable(command);
}
private void dtd(AssemblerContext context)
{
final DTDToken token = context.next(DTDToken.class);
context.add(new PageAssemblyAction()
{
public void execute(PageAssembly pageAssembly)
{
if (!pageAssembly.checkAndSetFlag("dtd-page-element-added"))
{
RenderCommand command = new DTDPageElement(token.getName(), token.getPublicId(), token
.getSystemId());
// It doesn't really matter where this ends up in the tree as long as its inside
// a portion that always renders.
pageAssembly.addRenderCommand(command);
}
}
});
}
private void parameter(AssemblerContext context)
{
final ParameterToken token = context.next(ParameterToken.class);
context.add(new PageAssemblyAction()
{
public void execute(PageAssembly pageAssembly)
{
String parameterName = token.getName();
ComponentPageElement element = pageAssembly.createdElement.peek();
BlockImpl block = new BlockImpl(token.getLocation(), interner.format("Parameter %s of %s",
parameterName, element.getCompleteId()));
Binding binding = new LiteralBinding(token.getLocation(), "block parameter " + parameterName, block);
EmbeddedComponentAssembler embeddedAssembler = pageAssembly.embeddedAssembler.peek();
ParameterBinder binder = embeddedAssembler.createParameterBinder(parameterName);
if (binder == null) { throw new TapestryException(PageloadMessages.parameterNotSupported(
element.getCompleteId(), parameterName), token.getLocation(), null); }
binder.bind(pageAssembly.createdElement.peek(), binding);
pageAssembly.bodyElement.push(block);
}
});
consumeToEndElementAndPopBodyElement(context);
}
private void block(AssemblerContext context)
{
final BlockToken token = context.next(BlockToken.class);
context.add(new PageAssemblyAction()
{
public void execute(PageAssembly pageAssembly)
{
String blockId = token.getId();
ComponentPageElement element = pageAssembly.activeElement.peek();
String description = blockId == null ? interner.format("Anonymous within %s", element.getCompleteId())
: interner.format("%s within %s", blockId, element.getCompleteId());
BlockImpl block = new BlockImpl(token.getLocation(), description);
if (blockId != null)
element.addBlock(blockId, block);
// Start directing template content into the Block
pageAssembly.bodyElement.push(block);
}
});
consumeToEndElementAndPopBodyElement(context);
}
private void consumeToEndElementAndPopBodyElement(AssemblerContext context)
{
while (true)
{
switch (context.peekType())
{
case END_ELEMENT:
context.next();
context.add(new PageAssemblyAction()
{
public void execute(PageAssembly pageAssembly)
{
pageAssembly.bodyElement.pop();
}
});
return;
default:
processTemplateToken(context);
}
}
}
private void comment(AssemblerContext context)
{
CommentToken token = context.next(CommentToken.class);
RenderCommand commentElement = new CommentPageElement(token.getComment());
context.addComposable(commentElement);
}
private void component(AssemblerContext context)
{
EmbeddedComponentAssembler embeddedAssembler = startComponent(context);
while (true)
{
switch (context.peekType())
{
case ATTRIBUTE:
bindAttributeAsParameter(context, embeddedAssembler);
break;
case END_ELEMENT:
context.next();
context.add(POP_EMBEDDED_COMPONENT_ACTION);
return;
default:
processTemplateToken(context);
}
}
}
private void bindAttributeAsParameter(AssemblerContext context, EmbeddedComponentAssembler embeddedAssembler)
{
AttributeToken token = context.next(AttributeToken.class);
addParameterBindingAction(context, embeddedAssembler, token.getName(), token.getValue(),
BindingConstants.LITERAL, token.getLocation());
}
private void element(AssemblerContext context)
{
StartElementToken token = context.next(StartElementToken.class);
RenderCommand element = new StartElementPageElement(token.getNamespaceURI(), token.getName());
context.addComposable(element);
while (true)
{
switch (context.peekType())
{
case ATTRIBUTE:
attribute(context);
break;
case END_ELEMENT:
context.next();
context.addComposable(END_ELEMENT);
// Pop out a level.
return;
default:
processTemplateToken(context);
}
}
}
private EmbeddedComponentAssembler startComponent(AssemblerContext context)
{
StartComponentToken token = context.next(StartComponentToken.class);
ComponentAssembler assembler = context.assembler;
String elementName = token.getElementName();
// Initial guess: the type from the token (but this may be null in many cases).
String embeddedType = token.getComponentType();
// This may be null for an anonymous component.
String embeddedId = token.getId();
String embeddedComponentClassName = null;
final EmbeddedComponentModel embeddedModel = embeddedId == null ? null : assembler.getModel()
.getEmbeddedComponentModel(embeddedId);
if (embeddedId == null)
embeddedId = assembler.generateEmbeddedId(embeddedType);
if (embeddedModel != null)
{
String modelType = embeddedModel.getComponentType();
if (InternalUtils.isNonBlank(modelType) && embeddedType != null) { throw new TapestryException(
PageloadMessages.redundantEmbeddedComponentTypes(embeddedId, embeddedType, modelType), token, null); }
embeddedType = modelType;
embeddedComponentClassName = embeddedModel.getComponentClassName();
}
String componentClassName = embeddedComponentClassName;
// This awkwardness is making me think that the page loader should resolve the component
// type before invoking this method (we would then remove the componentType parameter).
if (InternalUtils.isNonBlank(embeddedType))
{
// The type actually overrides the specified class name. The class name is defined
// by the type of the field. In many scenarios, the field type is a common
// interface,
// and the type is used to determine the concrete class to instantiate.
try
{
componentClassName = componentClassResolver.resolveComponentTypeToClassName(embeddedType);
}
catch (RuntimeException ex)
{
throw new TapestryException(ex.getMessage(), token, ex);
}
}
// OK, now we can record an action to get it instantiated.
EmbeddedComponentAssembler embeddedAssembler = assembler.createEmbeddedAssembler(embeddedId,
componentClassName, embeddedModel, token.getMixins(), token.getLocation());
addActionForEmbeddedComponent(context, embeddedAssembler, embeddedId, elementName, componentClassName);
addParameterBindingActions(context, embeddedAssembler, embeddedModel);
if (embeddedModel != null && embeddedModel.getInheritInformalParameters())
{
// Another two-step: The first "captures" the container and embedded component. The second
// occurs at the end of the page setup.
assembler.add(new PageAssemblyAction()
{
public void execute(PageAssembly pageAssembly)
{
final ComponentPageElement container = pageAssembly.activeElement.peek();
final ComponentPageElement embedded = pageAssembly.createdElement.peek();
pageAssembly.deferred.add(new PageAssemblyAction()
{
public void execute(PageAssembly pageAssembly)
{
copyInformalParameters(container, embedded);
}
});
}
});
}
return embeddedAssembler;
}
private void copyInformalParameters(ComponentPageElement container, ComponentPageElement embedded)
{
// TODO: Much more, this is an area where we can make things a bit more efficient by tracking
// what has and hasn't been bound in the EmbeddedComponentAssembler (and identifying what is
// and isn't informal).
ComponentModel model = embedded.getComponentResources().getComponentModel();
Map<String, Binding> informals = container.getInformalParameterBindings();
for (String name : informals.keySet())
{
if (model.getParameterModel(name) != null)
continue;
Binding binding = informals.get(name);
embedded.bindParameter(name, binding);
}
}
private void addParameterBindingActions(AssemblerContext context, EmbeddedComponentAssembler embeddedAssembler,
EmbeddedComponentModel embeddedModel)
{
if (embeddedModel == null)
return;
for (String parameterName : embeddedModel.getParameterNames())
{
String parameterValue = embeddedModel.getParameterValue(parameterName);
addParameterBindingAction(context, embeddedAssembler, parameterName, parameterValue, BindingConstants.PROP,
embeddedModel.getLocation());
}
}
private void addParameterBindingAction(AssemblerContext context,
final EmbeddedComponentAssembler embeddedAssembler, final String parameterName,
final String parameterValue, final String metaDefaultBindingPrefix, final Location location)
{
if (embeddedAssembler.isBound(parameterName))
return;
embeddedAssembler.setBound(parameterName);
if (parameterValue.startsWith(InternalConstants.INHERIT_BINDING_PREFIX))
{
String containerParameterName = parameterValue.substring(InternalConstants.INHERIT_BINDING_PREFIX.length());
addInheritedBindingAction(context, parameterName, containerParameterName);
return;
}
context.add(new PageAssemblyAction()
{
public void execute(PageAssembly pageAssembly)
{
// Because of published parameters, we have to wait until page assembly time to throw out
// informal parameters bound to components that don't support informal parameters ...
// otherwise we'd throw out (sometimes!) published parameters.
final ParameterBinder binder = embeddedAssembler.createParameterBinder(parameterName);
// Null meaning an informal parameter and the component (and mixins) doesn't support informals.
if (binder != null)
{
final String defaultBindingPrefix = binder.getDefaultBindingPrefix(metaDefaultBindingPrefix);
InternalComponentResources containerResources = pageAssembly.activeElement.peek()
.getComponentResources();
ComponentPageElement embeddedElement = pageAssembly.createdElement.peek();
InternalComponentResources embeddedResources = embeddedElement.getComponentResources();
Binding binding = elementFactory.newBinding(parameterName, containerResources, embeddedResources,
defaultBindingPrefix, parameterValue, location);
binder.bind(embeddedElement, binding);
}
}
});
}
/**
* Adds a deferred action to the PageAssembly, to handle connecting the embedded components' parameter to the
* container component's parameter once everything else has been built.
*
* @param context
* @param parameterName
* @param containerParameterName
*/
private void addInheritedBindingAction(AssemblerContext context, final String parameterName,
final String containerParameterName)
{
context.add(new PageAssemblyAction()
{
public void execute(PageAssembly pageAssembly)
{
// At the time this action executes, we'll be able to capture the containing and embedded
// component. We can then defer the connection logic until after all other construction.
final ComponentPageElement container = pageAssembly.activeElement.peek();
final ComponentPageElement embedded = pageAssembly.createdElement.peek();
// Parameters are normally bound bottom to top. Inherited parameters run differently, and should be
// top to bottom.
pageAssembly.deferred.add(new PageAssemblyAction()
{
public void execute(PageAssembly pageAssembly)
{
connectInheritedParameter(container, embedded, parameterName, containerParameterName);
}
});
}
});
}
private void connectInheritedParameter(ComponentPageElement container, ComponentPageElement embedded,
String parameterName, String containerParameterName)
{
// TODO: This assumes that the two parameters are both on the core component and not on
// a mixin. I think this could be improved with more static analysis.
Binding containerBinding = container.getBinding(containerParameterName);
if (containerBinding == null)
return;
// This helps with debugging, and re-orients any thrown exceptions
// to the location of the inherited binding, rather than the container component's
// binding.
// Binding inherited = new InheritedBinding(description, containerBinding, embedded.getLocation());
embedded.bindParameter(parameterName, containerBinding);
}
private void addActionForEmbeddedComponent(AssemblerContext context,
final EmbeddedComponentAssembler embeddedAssembler, final String embeddedId, final String elementName,
final String componentClassName)
{
context.add(new PageAssemblyAction()
{
public void execute(PageAssembly pageAssembly)
{
pageAssembly.checkForRecursion(componentClassName, embeddedAssembler.getLocation());
ComponentResourceSelector selector = pageAssembly.page.getSelector();
ComponentAssembler assemblerForSubcomponent = getAssembler(componentClassName, selector);
// Remember: this pushes onto to the createdElement stack, but does not pop it.
assemblerForSubcomponent.assembleEmbeddedComponent(pageAssembly, embeddedAssembler, embeddedId,
elementName, embeddedAssembler.getLocation());
// ... which is why we can find it via peek() here. And it's our responsibility
// to clean it up.
ComponentPageElement embeddedElement = pageAssembly.createdElement.peek();
// Add the new element to the template of its container.
pageAssembly.addRenderCommand(embeddedElement);
// And redirect any futher content from this component's template to go into
// the body of the embedded element.
pageAssembly.bodyElement.push(embeddedElement);
pageAssembly.embeddedAssembler.push(embeddedAssembler);
// The means we need to pop the createdElement, bodyElement and embeddedAssembler stacks
// when done with this sub-component, which is what POP_EMBEDDED_COMPONENT_ACTION does.
}
});
}
private void attribute(AssemblerContext context)
{
final AttributeToken token = context.next(AttributeToken.class);
String value = token.getValue();
// No expansion makes this easier, more efficient.
if (value.indexOf(InternalConstants.EXPANSION_START) < 0)
{
RenderCommand command = new RenderAttribute(token);
context.addComposable(command);
return;
}
context.add(new PageAssemblyAction()
{
public void execute(PageAssembly pageAssembly)
{
InternalComponentResources resources = pageAssembly.activeElement.peek().getComponentResources();
RenderCommand command = elementFactory.newAttributeElement(resources, token);
pageAssembly.addRenderCommand(command);
}
});
}
private void body(AssemblerContext context)
{
context.add(new PageAssemblyAction()
{
public void execute(PageAssembly pageAssembly)
{
ComponentPageElement element = pageAssembly.activeElement.peek();
pageAssembly.addRenderCommand(new RenderBodyElement(element));
}
});
}
private void expansion(AssemblerContext context)
{
final ExpansionToken token = context.next(ExpansionToken.class);
context.add(new PageAssemblyAction()
{
public void execute(PageAssembly pageAssembly)
{
ComponentResources resources = pageAssembly.activeElement.peek().getComponentResources();
RenderCommand command = elementFactory.newExpansionElement(resources, token);
pageAssembly.addRenderCommand(command);
}
});
}
private void text(AssemblerContext context)
{
TextToken textToken = context.next(TextToken.class);
context.addComposable(new TextPageElement(textToken.getText()));
}
}