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// Metawidget
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

package org.metawidget.faces.component;

import static org.metawidget.inspector.InspectionResultConstants.*;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.MissingResourceException;
import java.util.ResourceBundle;

import javax.faces.application.Application;
import javax.faces.component.EditableValueHolder;
import javax.faces.component.UIComponent;
import javax.faces.component.UIInput;
import javax.faces.component.UIParameter;
import javax.faces.component.UIViewRoot;
import javax.faces.component.ValueHolder;
import javax.faces.context.ExternalContext;
import javax.faces.context.FacesContext;
import javax.faces.el.ValueBinding;
import javax.faces.event.AbortProcessingException;
import javax.faces.event.PreRenderViewEvent;
import javax.faces.event.SystemEvent;
import javax.faces.event.SystemEventListener;
import javax.faces.validator.Validator;

import org.metawidget.config.iface.ConfigReader;
import org.metawidget.config.impl.BaseConfigReader;
import org.metawidget.faces.FacesUtils;
import org.metawidget.iface.MetawidgetException;
import org.metawidget.inspectionresultprocessor.iface.InspectionResultProcessor;
import org.metawidget.inspector.iface.Inspector;
import org.metawidget.layout.iface.Layout;
import org.metawidget.pipeline.w3c.W3CPipeline;
import org.metawidget.util.ClassUtils;
import org.metawidget.util.CollectionUtils;
import org.metawidget.util.LogUtils;
import org.metawidget.util.WidgetBuilderUtils;
import org.metawidget.util.LogUtils.Log;
import org.metawidget.util.XmlUtils;
import org.metawidget.util.simple.StringUtils;
import org.metawidget.widgetbuilder.iface.WidgetBuilder;
import org.metawidget.widgetprocessor.iface.WidgetProcessor;
import org.w3c.dom.Element;

/**
 * Base Metawidget for Java Server Faces environments.
 * 

* Its default RendererType is table. *

*

Resolving Directly To A Single Widget

*

* If the entire Metawidget resolves directly to a single widget, Metawidget allows you to attach * converters, facets and validators to the dynamically chosen component. Tags placed inside the * Metawidget tag will be moved on to the generated component. For example: *

* <m:metawidget value="#{user.name}">
*    <f:validator validatorId="myValidator">
* </m:metawidget>
*

* Conceptually, UIMetawidget should only extend UIComponentBase. This is * because it is not: *

*

    *
  • a UIInput, though it may contain input widgets *
  • a UIOutput, though it may contain output widgets *
  • a ValueHolder, as it does not use a Converter *
  • an EditableValueHolder, as it does not use a Validator *
*

* However by extending UIInput, we enable this useful capability. * * @author Richard Kennard */ @SuppressWarnings( "deprecation" ) public abstract class UIMetawidget extends UIInput { // // Public statics // /** * Component-level attribute used to store metadata. */ public static final String COMPONENT_ATTRIBUTE_METADATA = "metawidget-metadata"; /** * Component-level attribute used to prevent recreation. *

* By default, Metawidget destroys and recreates every component after * processUpdates and before encodeBegin. This allows components to * update to reflect changed state in underlying business objects. For example, components may * change from being UIOutput labels to UIInput text boxes after the * user clicks Edit. *

* Most components work well with this approach. Some, however, maintain internal state that * would get lost if the component was destroyed and recreated. For example, the ICEfaces * SelectInputDate component keeps its popup state internally. If it is destroyed * and recreated, the popup never appears. *

* Such components can be marked with COMPONENT_ATTRIBUTE_NOT_RECREATABLE to * prevent their destruction and recreation. Of course, this somewhat impacts their flexibility. * For example, a SelectInputDate could not change its date format in response to * another component on the form. *

* COMPONENT_ATTRIBUTE_NOT_RECREATABLE is also used to mark components that * override default component generation, such as a UIStub used to suppress a * field. *

* This attribute must be used in conjunction with OverriddenWidgetBuilder. */ public static final String COMPONENT_ATTRIBUTE_NOT_RECREATABLE = "metawidget-not-recreatable"; /** * Component-level attribute used to store metadata. */ public static final String COMPONENT_ATTRIBUTE_SECTION_DECORATOR = "metawidget-section-decorator"; // // Private statics // /** * Application-level attribute used to cache ConfigReader. This can also be used to inject a * different ConfigReader if needed (ie. for Grails) */ private static final String APPLICATION_ATTRIBUTE_CONFIG_READER = "metawidget-config-reader"; private static final String DEFAULT_USER_CONFIG = "metawidget.xml"; private static final String COMPONENT_ATTRIBUTE_PARAMETER_PREFIX = "metawidget-parameter-"; /* package private */static final Log LOG = LogUtils.getLog( UIMetawidget.class ); /* package private */static boolean LOGGED_MISSING_CONFIG; private static Boolean USE_PRERENDER_VIEW_EVENT; // // Private members // /* package private */boolean mExplicitRendererType; private boolean mInspectFromParent; private boolean mReadOnly; private Map mClientProperties; /* package private */Pipeline mPipeline; /* package private */Object mBuildWidgetsSupport; // // Constructor // public UIMetawidget() { mPipeline = newPipeline(); // Default config FacesContext context = FacesContext.getCurrentInstance(); ExternalContext externalContext = context.getExternalContext(); String configFile = externalContext.getInitParameter( "org.metawidget.faces.component.CONFIG_FILE" ); if ( configFile == null ) { setConfig( DEFAULT_USER_CONFIG ); } else { setConfig( configFile ); } FacesContext facesContext = UIMetawidget.this.getFacesContext(); Map applicationMap = facesContext.getExternalContext().getApplicationMap(); ConfigReader configReader = (ConfigReader) applicationMap.get( APPLICATION_ATTRIBUTE_CONFIG_READER ); if ( configReader == null ) { configReader = new BaseConfigReader( new FacesResourceResolver() ); applicationMap.put( APPLICATION_ATTRIBUTE_CONFIG_READER, configReader ); } mPipeline.setConfigReader( configReader ); // Default renderer (not set mExplicitRendererType yet) super.setRendererType( "table" ); mExplicitRendererType = false; registerBuildWidgetsSupport(); } // // Public methods // @Override public String getFamily() { return "org.metawidget"; } public boolean isReadOnly() { // Dynamic read-only (takes precedence if set) ValueBinding bindingReadOnly = getValueBinding( "readOnly" ); if ( bindingReadOnly != null ) { return (Boolean) bindingReadOnly.getValue( getFacesContext() ); } // Default to read-write return mReadOnly; } public void setReadOnly( boolean readOnly ) { mReadOnly = readOnly; } public void setConfig( String config ) { mPipeline.setConfig( config ); } public void setInspector( Inspector inspector ) { mPipeline.setInspector( inspector ); } /** * Useful for WidgetBuilders to perform nested inspections (eg. for Collections). */ public String inspect( Object toInspect, String type, String... names ) { return mPipeline.inspect( toInspect, type, names ); } public void addInspectionResultProcessor( InspectionResultProcessor inspectionResultProcessor ) { mPipeline.addInspectionResultProcessor( inspectionResultProcessor ); } public void removeInspectionResultProcessor( InspectionResultProcessor inspectionResultProcessor ) { mPipeline.removeInspectionResultProcessor( inspectionResultProcessor ); } public void setInspectionResultProcessors( InspectionResultProcessor... inspectionResultProcessors ) { mPipeline.setInspectionResultProcessors( inspectionResultProcessors ); } public void setWidgetBuilder( WidgetBuilder widgetBuilder ) { mPipeline.setWidgetBuilder( widgetBuilder ); } /** * Exposed mainly for those using UIComponent.setBinding. */ public WidgetBuilder getWidgetBuilder() { return mPipeline.getWidgetBuilder(); } /** * Exposed mainly for those using UIComponent.setBinding. */ public void addWidgetProcessor( WidgetProcessor widgetProcessor ) { mPipeline.addWidgetProcessor( widgetProcessor ); } /** * Exposed mainly for those using UIComponent.setBinding. */ public void removeWidgetProcessor( WidgetProcessor widgetProcessor ) { mPipeline.removeWidgetProcessor( widgetProcessor ); } public void setWidgetProcessors( WidgetProcessor... widgetProcessors ) { mPipeline.setWidgetProcessors( widgetProcessors ); } public List> getWidgetProcessors() { return mPipeline.getWidgetProcessors(); } public T getWidgetProcessor( Class widgetProcessorClass ) { return mPipeline.getWidgetProcessor( widgetProcessorClass ); } public void setLayout( Layout layout ) { mPipeline.setLayout( layout ); } public Layout getLayout() { return mPipeline.getLayout(); } /** * Instructs the Metawidget to inspect the value binding from the parent. *

* If the value binding is of the form #{foo.bar}, sometimes * foo.getBar() has useful metadata (such as UiLookup). Metawidget * inspects from parent anyway if #{foo.bar} evaluates to null, but on * occasion it may be necessary to specify parent inspection explicitly. *

* The disadvantage of inspecting from parent (and the reason it is not enabled by default) is * that some Inspectors will not know the parent and so not be able to return anything. For * example, HibernateInspector only knows the Hibernate XML mapping files of persistent classes, * not the business class of a UI controller, so asking HibernateInspector to inspect * #{controller.current} from its parent will always return null. */ public void setInspectFromParent( boolean inspectFromParent ) { mInspectFromParent = inspectFromParent; } /** * @return the text of the label. This may itself contain a value expression, such as * UiLabel( "#{foo.name}'s name" ) */ public String getLabelString( Map attributes ) { if ( attributes == null ) { return ""; } // Explicit label String label = attributes.get( LABEL ); if ( label != null ) { // (may be forced blank) if ( "".equals( label ) ) { return null; } // (localize if possible) String localized = getLocalizedKey( StringUtils.camelCase( label ) ); if ( localized != null ) { return localized.trim(); } return label.trim(); } // Default name String name = attributes.get( NAME ); if ( name != null ) { // (localize if possible) String localized = getLocalizedKey( name ); if ( localized != null ) { return localized.trim(); } return StringUtils.uncamelCase( name ); } return ""; } /** * @return null if no bundle, ???key??? if bundle is missing a key */ public String getLocalizedKey( String key ) { String localizedKey = null; FacesContext context = FacesContext.getCurrentInstance(); Application application = context.getApplication(); String appBundle = application.getMessageBundle(); // Component-specific bundle ValueBinding bindingBundle = getValueBinding( "bundle" ); if ( bindingBundle != null ) { // (watch out when localizing blank labels) if ( key == null || key.trim().length() == 0 ) { return ""; } @SuppressWarnings( "unchecked" ) Map bundleMap = (Map) bindingBundle.getValue( context ); // (check for containsKey first, because BundleMap will return a dummy value otherwise) if ( bundleMap.containsKey( key ) ) { localizedKey = bundleMap.get( key ); } } // App-specific bundle else if ( appBundle != null ) { try { localizedKey = ResourceBundle.getBundle( appBundle, context.getViewRoot().getLocale() ).getString( key ); } catch ( MissingResourceException e ) { // Fail gracefully: we seem to have problems locating, say, // org.jboss.seam.core.SeamResourceBundle? return null; } } // No bundle else { return null; } if ( localizedKey != null ) { return localizedKey; } return StringUtils.RESOURCE_KEY_NOT_FOUND_PREFIX + key + StringUtils.RESOURCE_KEY_NOT_FOUND_SUFFIX; } /** * Sets the parameter with the given name to the given value. *

* This method will not override existing, manually specified <f:param />. * Rather it will store the given parameter in UIComponent.getAttributes. This has * several advantages: *

*

    *
  • Creating child UIParameter components for every parameter seems very heavy
  • *
  • Copying parameters to nested Metawidgets can be done using the getAttributes * Map, without needing to create nested UIParameter components
  • *
  • Nested UIParameter components complicate removeRecreatableChildren because * although they are not manually specified, they will not be automatically recreated either
  • *
*

* A disadvantage of this approach is that clients should always use * UIMetawidget.getParameter to retrieve parameters, rather than searching for * UIParameter components directly. */ public void setParameter( String name, Object value ) { getAttributes().put( COMPONENT_ATTRIBUTE_PARAMETER_PREFIX + name, value ); } /** * Gets the parameter with the given name. *

* As discussed in the setParameter JavaDoc, clients should use this method to * retrieve parameters, rather than searching for UIParameter components directly. */ public String getParameter( String name ) { // Try UIParameters first... for ( UIComponent child : getChildren() ) { if ( !( child instanceof UIParameter ) ) { continue; } // ...with the name we're interested in UIParameter parameter = (UIParameter) child; if ( name.equals( parameter.getName() ) ) { return (String) parameter.getValue(); } } // ...then our internal parameters return (String) getAttributes().get( COMPONENT_ATTRIBUTE_PARAMETER_PREFIX + name ); } /** * As discussed in the setParameter JavaDoc, clients should use this method to * copy parameters, rather than creating UIParameter components directly. */ public void copyParameters( UIMetawidget copyFrom ) { // Copy each child UIParameter for ( UIComponent component : copyFrom.getChildren() ) { if ( !( component instanceof UIParameter ) ) { continue; } UIParameter parameter = (UIParameter) component; setParameter( parameter.getName(), parameter.getValue() ); } // Copy each internal parameter too for ( Map.Entry entry : copyFrom.getAttributes().entrySet() ) { if ( !entry.getKey().startsWith( COMPONENT_ATTRIBUTE_PARAMETER_PREFIX ) ) { continue; } getAttributes().put( entry.getKey(), entry.getValue() ); } } /** * Storage area for WidgetProcessors, Layouts, and other stateless clients. *

* Unlike .setAttribute, these values are not serialized by * ResponseStateManagerImpl. */ public void putClientProperty( Object key, Object value ) { if ( mClientProperties == null ) { mClientProperties = CollectionUtils.newHashMap(); } mClientProperties.put( key, value ); } /** * Storage area for WidgetProcessors, Layouts, and other stateless clients. *

* Unlike .getAttribute, these values are not serialized by * ResponseStateManagerImpl. */ @SuppressWarnings( "unchecked" ) public T getClientProperty( Object key ) { if ( mClientProperties == null ) { return null; } return (T) mClientProperties.get( key ); } @Override public boolean isRendered() { boolean rendered = super.isRendered(); if ( mBuildWidgetsSupport instanceof EncodeBeginSupport ) { ( (EncodeBeginSupport) mBuildWidgetsSupport ).isRendered( rendered ); } return rendered; } /** * Overridden to flag whether the rendererType has been set explicitly by the page. *

* This stops global defaults, if defined in metawidget.xml, from overriding the * page-level renderType. This is because metawidget.xml is not parsed until * after setRendererType has been called. */ @Override public void setRendererType( String rendererType ) { mExplicitRendererType = true; super.setRendererType( rendererType ); } @Override public void encodeBegin( FacesContext context ) throws IOException { if ( mBuildWidgetsSupport instanceof EncodeBeginSupport ) { ( (EncodeBeginSupport) mBuildWidgetsSupport ).encodeBegin(); } super.encodeBegin( context ); } /** * Get the component type used to create this Metawidget. *

* Usually, clients will want to create a nested-Metawidget using the same subclass as * themselves. To be 'proper' in JSF, though, we should go via * application.createComponent. Unfortunately by default a UIComponent does not * know its own component type, so subclasses must override this method. *

* This method is public for use by NestedLayoutDecorators. */ public abstract String getComponentType(); /** * Useful for WidgetBuilders to setup nested Metawidgets (eg. for wrapping them in a * h:column). */ public void initNestedMetawidget( UIMetawidget nestedMetawidget, Map attributes ) { // Don't reconfigure... nestedMetawidget.setConfig( null ); // ...instead, copy runtime values mPipeline.initNestedPipeline( nestedMetawidget.mPipeline, attributes ); // Read-only // // Note: initNestedPipeline takes care of literal values. This is concerned with the value // binding if ( !WidgetBuilderUtils.isReadOnly( attributes ) ) { ValueBinding bindingReadOnly = getValueBinding( "readOnly" ); if ( bindingReadOnly != null ) { nestedMetawidget.setValueBinding( "readOnly", bindingReadOnly ); } } // Bundle nestedMetawidget.setValueBinding( "bundle", getValueBinding( "bundle" ) ); // Renderer type nestedMetawidget.setRendererType( getRendererType() ); // Parameters nestedMetawidget.copyParameters( this ); // Note: it is very dangerous to do, say... // // to.getAttributes().putAll( from.getAttributes() ); // // ...in order to copy all arbitary attributes, because some frameworks (eg. Facelets) use // the attributes map as a storage area for special flags (eg. // ComponentSupport.MARK_CREATED) that should not get copied down from component to // component! } @Override public Object saveState( FacesContext context ) { Object values[] = new Object[5]; values[0] = super.saveState( context ); values[1] = mExplicitRendererType; values[2] = mReadOnly; values[3] = mPipeline.getConfig(); values[4] = mInspectFromParent; return values; } @Override public void restoreState( FacesContext context, Object state ) { if ( !( state instanceof Object[] ) ) { throw MetawidgetException.newException( "State not Object[]. See http://java.net/jira/browse/JAVASERVERFACES-2283 for analysis of this issue" ); } Object values[] = (Object[]) state; super.restoreState( context, values[0] ); mExplicitRendererType = (Boolean) values[1]; mReadOnly = (Boolean) values[2]; mPipeline.setConfig( values[3] ); mInspectFromParent = (Boolean) values[4]; } // // Protected methods // /** * Instantiate the Pipeline used by this Metawidget. *

* Subclasses wishing to use their own Pipeline should override this method to instantiate their * version. */ protected Pipeline newPipeline() { return new Pipeline(); } /** * Register the mechanism used to build widgets. *

* Subclasses wishing to use their own mechanism should override this method to instantiate * their version. */ protected void registerBuildWidgetsSupport() { FacesContext context = FacesContext.getCurrentInstance(); ExternalContext externalContext = context.getExternalContext(); // PreRenderViewEvent support // // This is dependent on http://java.net/jira/browse/JAVASERVERFACES-2283 // and https://issues.apache.org/jira/browse/MYFACES-2935. It is decided once, statically, // for the duration if ( USE_PRERENDER_VIEW_EVENT == null ) { // Use context.class. Using context.application.class returns 'JBoss Application Server // Weld Integration EE Webtier services' under JBoss AS 6 Package contextPackage = context.getClass().getPackage(); String contextImplementationTitle = contextPackage.getImplementationTitle(); String contextImplementationVersion = contextPackage.getImplementationVersion(); if ( TRUE.equals( externalContext.getInitParameter( "org.metawidget.faces.component.DONT_USE_PRERENDER_VIEW_EVENT" ) ) ) { if ( isBadMojarra2( contextImplementationTitle, contextImplementationVersion ) && !FacesUtils.isPartialStateSavingDisabled() ) { throw MetawidgetException.newException( contextImplementationTitle + " " + contextImplementationVersion + " requires setting 'javax.faces.PARTIAL_STATE_SAVING' to 'false'. Or upgrade Mojarra to a version that includes this fix: http://java.net/jira/browse/JAVASERVERFACES-2283" ); } else if ( isBadMyFaces2( contextImplementationTitle, contextImplementationVersion ) && !FacesUtils.isPartialStateSavingDisabled() ) { throw MetawidgetException.newException( contextImplementationTitle + " " + contextImplementationVersion + " requires setting 'javax.faces.PARTIAL_STATE_SAVING' to 'false'. Or upgrade MyFaces to a version that includes this fix: https://issues.apache.org/jira/browse/MYFACES-2935" ); } // Forcibly disabled USE_PRERENDER_VIEW_EVENT = Boolean.FALSE; } else if ( FacesUtils.isJsf2() ) { if ( isBadMojarra2( contextImplementationTitle, contextImplementationVersion ) ) { throw MetawidgetException.newException( contextImplementationTitle + " " + contextImplementationVersion + " requires setting 'org.metawidget.faces.component.DONT_USE_PRERENDER_VIEW_EVENT' to 'true'. Or upgrade Mojarra to a version that includes this fix: http://java.net/jira/browse/JAVASERVERFACES-2283" ); } else if ( isBadMyFaces2( contextImplementationTitle, contextImplementationVersion ) ) { throw MetawidgetException.newException( contextImplementationTitle + " " + contextImplementationVersion + " requires setting 'org.metawidget.faces.component.DONT_USE_PRERENDER_VIEW_EVENT' to 'true'. Or upgrade MyFaces to a version that includes this fix: https://issues.apache.org/jira/browse/MYFACES-2935" ); } if ( context.getViewRoot() == null ) { // No ViewRoot? Maybe PARTIAL_STATE_SAVING disabled under MyFaces? USE_PRERENDER_VIEW_EVENT = Boolean.FALSE; } else { // Supported USE_PRERENDER_VIEW_EVENT = Boolean.TRUE; } } else { // JSF 1.x USE_PRERENDER_VIEW_EVENT = Boolean.FALSE; } } if ( Boolean.TRUE.equals( USE_PRERENDER_VIEW_EVENT ) ) { mBuildWidgetsSupport = new PreRenderViewEventSupport( this ); } else { mBuildWidgetsSupport = new EncodeBeginSupport( this ); } } protected void buildWidgets() throws Exception { // Inspect from the value binding... ValueBinding valueBinding = getValueBinding( "value" ); if ( valueBinding != null ) { mPipeline.buildWidgets( inspect( valueBinding, mInspectFromParent ) ); return; } // ...or from a raw value (for jBPM)... Object value = getValue(); if ( value instanceof String ) { mPipeline.buildWidgets( mPipeline.inspectAsDom( null, (String) value ) ); return; } // ...or a Class (for 'binding' attribute)... if ( value instanceof Class ) { mPipeline.buildWidgets( mPipeline.inspectAsDom( null, ( (Class) value ).getName() ) ); return; } // ...or a direct Object (for 'binding' attribute)... if ( value != null ) { mPipeline.buildWidgets( mPipeline.inspectAsDom( value, value.getClass().getName() ) ); return; } // ...or run without inspection (using the Metawidget purely for layout) mPipeline.buildWidgets( null ); } protected abstract String getDefaultConfiguration(); /** * Build child widgets. */ protected void startBuild() { LOG.trace( "startBuild" ); // Metawidget has no valueBinding? Won't be destroying/recreating any components, then. // // This is an optimisation, but is also important for cases like RichFacesLayout, which // use nested Metawidgets (without a value binding) purely for layout. They populate a new // Metawidget with previously inspected components, and we don't want them destroyed // here and/or unnecessarily re-inspected in endBuild // // Check getValue() is null too, in case the Metawidget is being used with direct objects // or direct classes (through the 'binding' attribute) if ( getValueBinding( "value" ) == null && getValue() == null ) { return; } // Remove any components we created previously (this is // important for polymorphic controls, which may change from // refresh to refresh) List children = getChildren(); for ( Iterator i = children.iterator(); i.hasNext(); ) { UIComponent componentChild = i.next(); Map attributes = componentChild.getAttributes(); // The first time in, children will have no metadata attached. Use this opportunity // to tag the initial children so that we never recreate them if ( !attributes.containsKey( COMPONENT_ATTRIBUTE_METADATA ) ) { attributes.put( COMPONENT_ATTRIBUTE_NOT_RECREATABLE, true ); continue; } // Remove recreatable components if ( removeRecreatableChildren( componentChild ) ) { i.remove(); } } } /** * @param elementName * XML node name of the business field. Typically 'entity', 'property' or 'action'. * Never null */ protected void layoutWidget( UIComponent component, String elementName, Map attributes ) { Map componentAttributes = component.getAttributes(); componentAttributes.put( COMPONENT_ATTRIBUTE_METADATA, attributes ); // If this component already exists in the list, remove it and re-add it. This // enables us to sort existing, manually created components in the correct order // // Doing the remove here, rather than in SimpleLayout, ensures we always remove and // add for cases like moving a Stub from outside a TabPanel to inside it getChildren().remove( component ); // Look up any additional attributes Map additionalAttributes = mPipeline.getAdditionalAttributes( component ); if ( additionalAttributes != null ) { attributes.putAll( additionalAttributes ); } // BasePipeline will call .layoutWidget } protected void endBuild() { List children = getChildren(); // Inspect any remaining components, and sort them to the bottom for ( int loop = 0, index = 0, length = children.size(); loop < length; loop++ ) { UIComponent component = children.get( index ); // If this component has already been processed by the inspection (ie. contains // metadata), is not rendered, or is a UIParameter, skip it // // This is also handy for RichFacesLayout, which uses a nested Metawidget purely as a // layout tool: it populates a new Metawidget with some previously inspected components. // This check makes sure they aren't unnecessarily re-inspected here Map miscAttributes = component.getAttributes(); if ( miscAttributes.containsKey( COMPONENT_ATTRIBUTE_METADATA ) || !component.isRendered() || component instanceof UIParameter ) { index++; continue; } // Try and determine some metadata for the component by inspecting its binding. This // helps our layout display proper labels, required stars etc. - even for components // whose binding is not a descendant of our parent binding Map childAttributes = CollectionUtils.newHashMap(); miscAttributes.put( COMPONENT_ATTRIBUTE_METADATA, childAttributes ); ValueBinding binding = component.getValueBinding( "value" ); if ( binding != null ) { Element inspectionResult = inspect( binding, true ); if ( inspectionResult != null ) { childAttributes.putAll( XmlUtils.getAttributesAsMap( inspectionResult.getFirstChild() ) ); } } else { // If no found metadata, default to no section. // // This is so if a user puts, say, a in the component tree, it doesn't // appear inside an existing section childAttributes.put( SECTION, "" ); } mPipeline.layoutWidget( component, PROPERTY, childAttributes ); } LOG.trace( "endBuild" ); } // // Private methods // /** * Removes all recreatable children (i.e. not marked COMPONENT_ATTRIBUTE_NOT_RECREATABLE). Does * not remove top-level UIComponents if any of their * children are COMPONENT_ATTRIBUTE_NOT_RECREATABLE, but does remove as many of their * children as it can. This allows their siblings to still behave dynamically even if some * components are locked (e.g. SelectInputDate). * * @return true if all children were removed (i.e. none were marked not-recreatable). */ private boolean removeRecreatableChildren( UIComponent component ) { // Do not remove locked or overridden components... Map attributes = component.getAttributes(); if ( attributes.containsKey( COMPONENT_ATTRIBUTE_NOT_RECREATABLE ) ) { // ...but always remove their metadata, otherwise // they will not be removed/re-added (and therefore re-ordered) upon POSTback attributes.remove( COMPONENT_ATTRIBUTE_METADATA ); return false; } // Recurse into children. We may have an auto-generated 'not recreatable' (e.g. // SelectInputDate) or a manually added 'not recreatable', and we don't want to remove the // top-level for it. This includes children that are nested Metawidgets, and children that // are LayoutDecorators List children = component.getChildren(); for ( Iterator i = children.iterator(); i.hasNext(); ) { UIComponent componentChild = i.next(); if ( removeRecreatableChildren( componentChild ) ) { i.remove(); } } return children.isEmpty(); } /** * Inspect the value binding. *

* A value binding is optional. UIMetawidget can be used purely to lay out manually-specified * components */ private Element inspect( ValueBinding valueBinding, boolean inspectFromParent ) { if ( valueBinding == null ) { return null; } // Inspect the object directly FacesContext context = getFacesContext(); String valueBindingString = valueBinding.getExpressionString(); if ( !inspectFromParent || !FacesUtils.isExpression( valueBindingString ) ) { Object toInspect = valueBinding.getValue( context ); if ( toInspect != null && !ClassUtils.isPrimitiveWrapper( toInspect.getClass() ) ) { return mPipeline.inspectAsDom( toInspect, toInspect.getClass().getName() ); } } // In the event the direct object is 'null' or a primitive... String binding = FacesUtils.unwrapExpression( valueBindingString ); // ...and the EL expression is such that we can chop it off to get to the parent... // // Note: using EL functions in generated ValueExpressions only works in JSF 2.0, // see https://javaserverfaces.dev.java.net/issues/show_bug.cgi?id=813. A workaround is // to assign the function's return value to a temporary, request-scoped variable using c:set if ( binding.indexOf( ' ' ) == -1 && binding.indexOf( ':' ) == -1 && binding.indexOf( '(' ) == -1 ) { int lastIndexOf = binding.lastIndexOf( StringUtils.SEPARATOR_DOT_CHAR ); if ( lastIndexOf != -1 ) { // ...traverse from the parent as there may be useful metadata there (such as 'name' // and 'type') Application application = context.getApplication(); ValueBinding bindingParent = application.createValueBinding( FacesUtils.wrapExpression( binding.substring( 0, lastIndexOf ) ) ); Object toInspect = bindingParent.getValue( context ); if ( toInspect != null ) { return mPipeline.inspectAsDom( toInspect, toInspect.getClass().getName(), binding.substring( lastIndexOf + 1 ) ); } } } LOG.debug( "No inspectors matched {0} (evaluated to null)", valueBindingString ); return null; } /** * Mojarra 2.x requires a fix for http://java.net/jira/browse/JAVASERVERFACES-2283. */ private boolean isBadMojarra2( String contextImplementationTitle, String contextImplementationVersion ) { if ( contextImplementationTitle == null ) { return false; } if ( !contextImplementationTitle.contains( "Mojarra" ) ) { return false; } if ( contextImplementationVersion.contains( "2.1." ) || contextImplementationVersion.contains( "2.2." ) ) { return true; } return contextImplementationVersion.contains( "2.0." ); } /** * MyFaces 2.x requires a fix for https://issues.apache.org/jira/browse/MYFACES-2935 (and * ideally https://issues.apache.org/jira/browse/MYFACES-3010 too). */ private boolean isBadMyFaces2( String contextImplementationTitle, String contextImplementationVersion ) { if ( contextImplementationTitle == null ) { return false; } if ( !contextImplementationTitle.contains( "MyFaces" ) ) { return false; } if ( contextImplementationVersion.contains( "2.1.10" ) || contextImplementationVersion.contains( "2.1.11" ) || contextImplementationVersion.contains( "2.1.12" ) ) { return true; } return ( contextImplementationVersion.contains( "2.0.0" ) || contextImplementationVersion.contains( "2.0.1" ) || contextImplementationVersion.contains( "2.0.2" ) ); } // // Inner class // protected class Pipeline extends W3CPipeline { // // Public methods // @Override protected void configure() { boolean wasExplicitRendererType = mExplicitRendererType; String rendererType = getRendererType(); try { super.configure(); } catch ( MetawidgetException e ) { if ( !DEFAULT_USER_CONFIG.equals( getConfig() ) || !( e.getCause() instanceof FileNotFoundException ) ) { throw e; } // Log a warning. Still log the Exception message, in case the FileNotFoundException // is from inside metawidget.xml, for example 'Unable to locate checkout.jpdl.xml on // CLASSPATH' if ( !LOGGED_MISSING_CONFIG ) { LOGGED_MISSING_CONFIG = true; LOG.info( "Could not locate " + DEFAULT_USER_CONFIG + ". This file is optional, but if you HAVE created one then Metawidget isn''t finding it: {0}", e.getMessage() ); } super.configureDefaults(); } // Preserve rendererType if was set explicitly if ( wasExplicitRendererType ) { setRendererType( rendererType ); } } @Override protected String getDefaultConfiguration() { return UIMetawidget.this.getDefaultConfiguration(); } /** * Overriden to just-in-time evaluate EL binding. */ @Override public boolean isReadOnly() { return UIMetawidget.this.isReadOnly(); } @Override public void setReadOnly( boolean readOnly ) { UIMetawidget.this.setReadOnly( readOnly ); } // // Protected methods // @Override protected void startBuild() { super.startBuild(); UIMetawidget.this.startBuild(); } @Override protected UIComponent buildWidget( String elementName, Map attributes ) { UIComponent entityLevelWidget = super.buildWidget( elementName, attributes ); // If we manage to build an entity-level widget, move our children *inside* it // // It's pretty rare we'll manage to create an entity-level widget, and even rarer that // we'll create one when we ourselves have children, but if we do this allows us to // attach, say, f:validator or f:ajax handlers to a dynamically chosen widget if ( entityLevelWidget != null && ENTITY.equals( elementName ) ) { // Move converters if ( entityLevelWidget instanceof ValueHolder ) { ValueHolder valueHolder = (ValueHolder) entityLevelWidget; valueHolder.setConverter( UIMetawidget.this.getConverter() ); // Do not UIMetawidget.this.setConverter( null ), else it will get lost for // subsequent POSTbacks } // Move facets Map metawidgetFacets = UIMetawidget.this.getFacets(); Map entityLevelWidgetFacets = entityLevelWidget.getFacets(); for ( Map.Entry entry : metawidgetFacets.entrySet() ) { UIComponent facet = entry.getValue(); entityLevelWidgetFacets.put( entry.getKey(), facet ); if ( mBuildWidgetsSupport instanceof EncodeBeginSupport ) { ( (EncodeBeginSupport) mBuildWidgetsSupport ).reassignFacet( facet ); } } metawidgetFacets.clear(); // Move validators if ( entityLevelWidget instanceof EditableValueHolder ) { EditableValueHolder entityLevelEditableValueHolder = (EditableValueHolder) entityLevelWidget; for ( Validator metawidgetValidator : UIMetawidget.this.getValidators() ) { entityLevelEditableValueHolder.addValidator( metawidgetValidator ); // Do not UIMetawidget.this.removeValidator( metawidgetValidator ), else // they will get lost for subsequent POSTbacks } } // It's not clear whether we should move .getChildren() too. Err on the side of // caution and don't for now } return entityLevelWidget; } @Override protected Map getAdditionalAttributes( UIComponent widget ) { if ( widget instanceof UIStub ) { return ( (UIStub) widget ).getStubAttributesAsMap(); } return null; } @Override protected UIMetawidget buildNestedMetawidget( Map attributes ) throws Exception { FacesContext context = FacesContext.getCurrentInstance(); UIMetawidget metawidget = (UIMetawidget) context.getApplication().createComponent( UIMetawidget.this.getComponentType() ); UIMetawidget.this.initNestedMetawidget( metawidget, attributes ); return metawidget; } @Override protected void layoutWidget( UIComponent component, String elementName, Map attributes ) { UIMetawidget.this.layoutWidget( component, elementName, attributes ); super.layoutWidget( component, elementName, attributes ); } @Override protected void endBuild() { super.endBuild(); UIMetawidget.this.endBuild(); } @Override protected UIMetawidget getPipelineOwner() { return UIMetawidget.this; } } /** * Dynamically modify the component tree using the JSF1 API. *

*

Background

*

* JSF1 did not have very good support for dynamically modifying the component tree. See * http://osdir.com/ml/java.facelets.user/2008-06/msg00050.html: *

* Jacob Hookum: "What's actually needed in [JSF 1.2] is post component tree creation or post * component creation hooks, providing the ability to then modify the component tree"
* Ken Paulsen: "This hasn't been resolved in the 2.0 EG yet" *

* We tried various workarounds: *

*

    *
  1. Triggering buildWidgets on getChildCount/getChildren. This does not work because those * methods get called at all sorts of other times
  2. *
  3. Doing it in super.encodeBegin for a GET, in processUpdates for a POST. This does not work * because the GET still records the bad components
  4. *
  5. A PhaseListener before PhaseId.RENDER_RESPONSE to trigger buildWidgets. This does not * work because UIViewRoot has no children at that stage in the lifecycle
  6. *
* JSF2 introduced SystemEvents to address this exact problem. See * PreRenderViewEventSupport below. *

*

Why It's A Problem

*

* JSF actually has (sort of) two component trees: the one in the ViewState, and the * components in the original JSP page. The latter is re-merged with the former, then the whole * lot is serialized. This happens after processUpdates but before * encodeBegin, which is a bit of a 'dead zone' for hooking into under JSF1. *

* It can cause an Exception if the original JSP contains a manually coded control (such as an * h:inputHidden) that subsequently gets moved into a Metawidget-generated sub-container (such * as a rich:simpleTogglePanel). Now there are two versions of the component: one in the * original JSP and one in a different place in the ViewState. *

* This hack removes that duplicate. */ private static class EncodeBeginSupport extends BuildWidgetsSupport { // // Constructor // public EncodeBeginSupport( UIMetawidget metawidget ) { super( metawidget ); } // // Public methods // /** * If the component is never going to be rendered, then encodeBegin will never * get called. Therefore our 'remove duplicates' code will never get called either. */ public void isRendered( boolean rendered ) { // Note: we explored not doing this until after the processUpdates phase, in case // the value of 'rendered' changes, but it didn't seem to make any difference to our // unit tests? if ( !rendered ) { getMetawidget().getChildren().clear(); } } /** * Modify the component tree during encodeBegin. This is not the cleanest, but * is the best we can do under JSF 1.x */ public void encodeBegin() throws IOException { try { // Remove duplicate children // // Remove the top-level version of each duplicate, not the nested-level version, // because the top-level is the 'original' whereas the nested-level is the // 'moved' (i.e. at its final destination). for ( Iterator i = getMetawidget().getChildren().iterator(); i.hasNext(); ) { UIComponent component = i.next(); if ( findDuplicateChild( getMetawidget(), component ) != null ) { i.remove(); } } buildWidgets(); } catch ( Exception e ) { // IOException does not take a Throwable 'cause' argument until Java 6, so // as we need to stay 1.5 compatible we output the trace here LogUtils.getLog( getClass() ).error( "Unable to encodeBegin", e ); // At this level, it is more 'proper' to throw an IOException than // a MetawidgetException, as that is what the layers above are expecting throw new IOException( e.getMessage() ); } } /** * Under JSF 1.x, facets will get duplicated just like children do. We can clean them up on * encodeBegin, but in the case of an AJAX POST-back we are not given that * chance. Instead, give them a new unique id. */ public void reassignFacet( UIComponent facet ) { facet.setId( FacesContext.getCurrentInstance().getViewRoot().createUniqueId() ); } // // Private methods // private UIComponent findDuplicateChild( UIComponent componentWithChildren, UIComponent originalComponent ) { String id = originalComponent.getId(); if ( id == null ) { return null; } for ( UIComponent child : componentWithChildren.getChildren() ) { if ( child == originalComponent ) { continue; } if ( id.equals( child.getId() ) ) { return child; } UIComponent found = findDuplicateChild( child, originalComponent ); if ( found != null ) { return found; } } return null; } } /** * Dynamically modify the component tree using the JSF2 API. *

* JSF2 introduced PreRenderViewEvent, which we can use to avoid * RemoveDuplicatesSupport. */ private static class PreRenderViewEventSupport extends BuildWidgetsSupport implements SystemEventListener { // // Constructor // public PreRenderViewEventSupport( UIMetawidget metawidget ) { super( metawidget ); FacesContext context = FacesContext.getCurrentInstance(); UIViewRoot root = context.getViewRoot(); if ( root == null ) { throw MetawidgetException.newException( "UIViewRoot is null. Is faces-config.xml set to version 2.0?" ); } root.subscribeToViewEvent( PreRenderViewEvent.class, this ); } // // Public methods // public boolean isListenerForSource( Object source ) { return ( source instanceof UIViewRoot ); } public void processEvent( SystemEvent event ) throws AbortProcessingException { // Don't do unnecessary work if none of our child components are to be rendered anyway // (work around for https://issues.apache.org/jira/browse/MYFACES-3293) if ( !getMetawidget().isRendered() ) { return; } // Don't run if we are not actually part of the View (HtmlWidgetBuilder uses us as a // dummy Metawidget) if ( getMetawidget().getParent() == null ) { return; } try { buildWidgets(); } catch ( Exception e ) { // At this level, it is more 'proper' to throw an AbortProcessingException than // a MetawidgetException, as that is what the layers above are expecting throw new AbortProcessingException( e ); } } } /** * Base implementation shared by EncodeBeginSupport and * PreRenderViewEventSupport. */ private static class BuildWidgetsSupport { // // Private members // private UIMetawidget mMetawidget; // // Constructor // public BuildWidgetsSupport( UIMetawidget metawidget ) { mMetawidget = metawidget; } // // Protected methods // protected UIMetawidget getMetawidget() { return mMetawidget; } protected void buildWidgets() throws Exception { // Validation error? Do not rebuild, as we will lose the invalid values in the // components if ( FacesUtils.isValidationFailed() ) { return; } // Build the widgets mMetawidget.buildWidgets(); } } }





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