// Copyright 2006, 2007 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.tapestry.internal.services;
import static org.apache.tapestry.TapestryConstants.PROP_BINDING_PREFIX;
import static org.apache.tapestry.ioc.internal.util.CollectionFactory.newList;
import java.util.List;
import org.apache.tapestry.Binding;
import org.apache.tapestry.ComponentResources;
import org.apache.tapestry.MarkupWriter;
import org.apache.tapestry.internal.parser.AttributeToken;
import org.apache.tapestry.internal.parser.CommentToken;
import org.apache.tapestry.internal.parser.DTDToken;
import org.apache.tapestry.internal.parser.ExpansionToken;
import org.apache.tapestry.internal.parser.StartElementToken;
import org.apache.tapestry.internal.parser.TextToken;
import org.apache.tapestry.internal.structure.CommentPageElement;
import org.apache.tapestry.internal.structure.ComponentPageElement;
import org.apache.tapestry.internal.structure.ComponentPageElementImpl;
import org.apache.tapestry.internal.structure.DTDPageElement;
import org.apache.tapestry.internal.structure.ExpansionPageElement;
import org.apache.tapestry.internal.structure.Page;
import org.apache.tapestry.internal.structure.PageElement;
import org.apache.tapestry.internal.structure.StartElementPageElement;
import org.apache.tapestry.internal.structure.TextPageElement;
import org.apache.tapestry.ioc.Location;
import org.apache.tapestry.ioc.internal.util.InternalUtils;
import org.apache.tapestry.ioc.internal.util.TapestryException;
import org.apache.tapestry.ioc.services.TypeCoercer;
import org.apache.tapestry.model.ComponentModel;
import org.apache.tapestry.runtime.RenderQueue;
import org.apache.tapestry.services.BindingSource;
import org.apache.tapestry.services.ComponentClassResolver;
import org.apache.tapestry.services.ComponentMessagesSource;
public class PageElementFactoryImpl implements PageElementFactory
{
private final ComponentInstantiatorSource _componentInstantiatorSource;
private final ComponentClassResolver _componentClassResolver;
private final TypeCoercer _typeCoercer;
private final BindingSource _bindingSource;
private final ComponentMessagesSource _messagesSource;
private static final String EXPANSION_START = "${";
private static class LiteralStringProvider implements StringProvider
{
private final String _string;
LiteralStringProvider(String string)
{
_string = string;
}
public String provideString()
{
return _string;
}
}
public PageElementFactoryImpl(ComponentInstantiatorSource componentInstantiatorSource,
ComponentClassResolver resolver, TypeCoercer typeCoercer, BindingSource bindingSource,
ComponentMessagesSource messagesSource)
{
_componentInstantiatorSource = componentInstantiatorSource;
_componentClassResolver = resolver;
_typeCoercer = typeCoercer;
_bindingSource = bindingSource;
_messagesSource = messagesSource;
}
/** Singleton instance that represents any close tag of any element in any template. */
private final PageElement _endElement = new PageElement()
{
public void render(MarkupWriter writer, RenderQueue queue)
{
writer.end();
}
@Override
public String toString()
{
return "End";
}
};
public PageElement newStartElement(StartElementToken token)
{
return new StartElementPageElement(token.getName());
}
public PageElement newTextElement(TextToken token)
{
return new TextPageElement(token.getText());
}
public PageElement newEndElement()
{
return _endElement;
}
public PageElement newAttributeElement(ComponentResources componentResources,
final AttributeToken token)
{
final StringProvider provider = parseAttributeExpansionExpression(
token.getValue(),
componentResources,
token.getLocation());
final String name = token.getName();
return new PageElement()
{
public void render(MarkupWriter writer, RenderQueue queue)
{
writer.attributes(name, provider.provideString());
}
};
}
private StringProvider parseAttributeExpansionExpression(String expression,
ComponentResources resources, final Location location)
{
final List<StringProvider> providers = newList();
int startx = 0;
while (true)
{
int expansionx = expression.indexOf(EXPANSION_START, startx);
// No more expansions, add in the rest of the string as a literal.
if (expansionx < 0)
{
if (startx < expression.length())
providers.add(new LiteralStringProvider(expression.substring(startx)));
break;
}
// Add in a literal string chunk for the characters between the last expansion and
// this expansion.
if (startx != expansionx)
providers.add(new LiteralStringProvider(expression.substring(startx, expansionx)));
int endx = expression.indexOf("}", expansionx);
if (endx < 0)
throw new TapestryException(ServicesMessages
.unclosedAttributeExpression(expression), location, null);
String expansion = expression.substring(expansionx + 2, endx);
final Binding binding = _bindingSource.newBinding(
"attribute expansion",
resources,
resources,
PROP_BINDING_PREFIX,
expansion,
location);
final StringProvider provider = new StringProvider()
{
public String provideString()
{
try
{
Object raw = binding.get();
return _typeCoercer.coerce(raw, String.class);
}
catch (Exception ex)
{
throw new TapestryException(ex.getMessage(), location, ex);
}
}
};
providers.add(provider);
// Restart the search after '}'
startx = endx + 1;
}
// Simplify the typical case, where the entire attribute is just a single expansion:
if (providers.size() == 1) return providers.get(0);
return new StringProvider()
{
public String provideString()
{
StringBuilder builder = new StringBuilder();
for (StringProvider provider : providers)
builder.append(provider.provideString());
return builder.toString();
}
};
}
public PageElement newExpansionElement(ComponentResources componentResources,
ExpansionToken token)
{
Binding binding = _bindingSource.newBinding(
"expansion",
componentResources,
componentResources,
PROP_BINDING_PREFIX,
token.getExpression(),
token.getLocation());
return new ExpansionPageElement(binding, _typeCoercer);
}
public ComponentPageElement newComponentElement(Page page, ComponentPageElement container,
String id, String componentType, String componentClassName, String elementName,
Location location)
{
try
{
String finalClassName = componentClassName;
// 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(componentType))
{
// 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
{
finalClassName = _componentClassResolver
.resolveComponentTypeToClassName(componentType);
}
catch (IllegalArgumentException ex)
{
throw new TapestryException(ex.getMessage(), location, ex);
}
}
Instantiator instantiator = _componentInstantiatorSource
.findInstantiator(finalClassName);
// This is actually a good place to check for recursive templates, here where we've
// resolved
// the component type to a fully qualified class name.
checkForRecursion(finalClassName, container, location);
// The container for any components is the loading component, regardless of
// how the component elements are nested within the loading component's
// template.
ComponentPageElementImpl result = new ComponentPageElementImpl(page, container, id,
elementName, instantiator, _typeCoercer, _messagesSource, location);
page.addLifecycleListener(result);
container.addEmbeddedElement(result);
addMixins(result, instantiator);
return result;
}
catch (RuntimeException ex)
{
throw new TapestryException(ex.getMessage(), location, ex);
}
}
private void checkForRecursion(String componentClassName, ComponentPageElement container,
Location location)
{
// Container may be null for a root element;
if (container == null) return;
ComponentResources resources = container.getComponentResources();
while (resources != null)
{
if (resources.getComponentModel().getComponentClassName().equals(componentClassName))
throw new TapestryException(
ServicesMessages.componentRecursion(componentClassName), location, null);
resources = resources.getContainerResources();
}
}
public ComponentPageElement newRootComponentElement(Page page, String componentType)
{
Instantiator instantiator = _componentInstantiatorSource.findInstantiator(componentType);
ComponentPageElementImpl result = new ComponentPageElementImpl(page, instantiator,
_typeCoercer, _messagesSource);
addMixins(result, instantiator);
page.addLifecycleListener(result);
return result;
}
private void addMixins(ComponentPageElement component, Instantiator instantiator)
{
ComponentModel model = instantiator.getModel();
for (String mixinClassName : model.getMixinClassNames())
addMixinByClassName(component, mixinClassName);
}
public PageElement newRenderBodyElement(final ComponentPageElement component)
{
return new PageElement()
{
public void render(MarkupWriter writer, RenderQueue queue)
{
component.enqueueBeforeRenderBody(queue);
}
@Override
public String toString()
{
return String.format("RenderBody[%s]", component.getNestedId());
}
};
}
public void addMixinByTypeName(ComponentPageElement component, String mixinType)
{
String mixinClassName = _componentClassResolver.resolveMixinTypeToClassName(mixinType);
addMixinByClassName(component, mixinClassName);
}
public void addMixinByClassName(ComponentPageElement component, String mixinClassName)
{
Instantiator mixinInstantiator = _componentInstantiatorSource
.findInstantiator(mixinClassName);
component.addMixin(mixinInstantiator);
}
public PageElement newCommentElement(CommentToken token)
{
return new CommentPageElement(token.getComment());
}
public PageElement newDTDElement(DTDToken token)
{
return new DTDPageElement(token.getName(), token.getPublicId(), token.getSystemId());
}
public Binding newBinding(String parameterName, ComponentResources loadingComponentResources,
ComponentResources embeddedComponentResources, String defaultBindingPrefix,
String expression, Location location)
{
if (expression.contains(EXPANSION_START))
{
StringProvider provider = parseAttributeExpansionExpression(
expression,
loadingComponentResources,
location);
return new AttributeExpansionBinding(provider, location);
}
return _bindingSource.newBinding(
"parameter " + parameterName,
loadingComponentResources,
embeddedComponentResources,
defaultBindingPrefix,
expression,
location);
}
}