com.sun.faces.facelets.tag.jsf.core.EventHandler Maven / Gradle / Ivy
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package com.sun.faces.facelets.tag.jsf.core;
import com.sun.faces.application.ApplicationAssociate;
import javax.el.ELContext;
import javax.el.MethodExpression;
import javax.el.MethodNotFoundException;
import javax.faces.FacesException;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.event.AbortProcessingException;
import javax.faces.event.ComponentSystemEvent;
import javax.faces.event.ComponentSystemEventListener;
import javax.faces.event.PostRenderViewEvent;
import javax.faces.event.SystemEvent;
import javax.faces.view.facelets.ComponentHandler;
import javax.faces.view.facelets.FaceletContext;
import javax.faces.view.facelets.TagAttribute;
import javax.faces.view.facelets.TagConfig;
import javax.faces.view.facelets.TagHandler;
import java.io.IOException;
import java.io.Serializable;
import javax.faces.component.UIViewRoot;
import javax.faces.event.PreRenderViewEvent;
/**
* This is the TagHandler for the f:event tag.
*/
public class EventHandler extends TagHandler {
protected final TagAttribute type;
protected final TagAttribute listener;
public EventHandler(TagConfig config) {
super(config);
this.type = this.getRequiredAttribute("type");
this.listener = this.getRequiredAttribute("listener");
}
@Override
public void apply(FaceletContext ctx, UIComponent parent) throws IOException {
if (ComponentHandler.isNew(parent)) {
Class eventClass = getEventClass(ctx);
UIViewRoot viewRoot = ctx.getFacesContext().getViewRoot();
// ensure that f:event can be used anywhere on the page for preRenderView and postRenderView,
// not just as a direct child of the viewRoot
if (null != viewRoot && (PreRenderViewEvent.class == eventClass || PostRenderViewEvent.class == eventClass) &&
parent != viewRoot) {
parent = viewRoot;
}
if (eventClass != null) {
parent.subscribeToEvent(eventClass,
new DeclarativeSystemEventListener(
listener.getMethodExpression(ctx, Object.class, new Class[] { ComponentSystemEvent.class }),
listener.getMethodExpression(ctx, Object.class, new Class[] { })));
}
}
}
protected Class getEventClass(FaceletContext ctx) {
String eventType = (String) this.type.getValueExpression(ctx, String.class).getValue(ctx);
if (eventType == null) {
throw new FacesException("Attribute 'type' can not be null");
}
return ApplicationAssociate.getInstance(ctx.getFacesContext().getExternalContext())
.getNamedEventManager().getNamedEvent(eventType);
}
}
class DeclarativeSystemEventListener implements ComponentSystemEventListener, Serializable {
private static final long serialVersionUID = 8945415935164238908L;
private MethodExpression oneArgListener;
private MethodExpression noArgListener;
// Necessary for state saving
public DeclarativeSystemEventListener() {}
public DeclarativeSystemEventListener(MethodExpression oneArg, MethodExpression noArg) {
this.oneArgListener = oneArg;
this.noArgListener = noArg;
}
@Override
public void processEvent(ComponentSystemEvent event) throws AbortProcessingException {
final ELContext elContext = FacesContext.getCurrentInstance().getELContext();
try{
noArgListener.invoke(elContext, new Object[]{});
} catch (MethodNotFoundException | IllegalArgumentException mnfe) {
// Attempt to call public void method(ComponentSystemEvent event)
oneArgListener.invoke(elContext, new Object[]{event});
}
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
DeclarativeSystemEventListener that = (DeclarativeSystemEventListener) o;
if (noArgListener != null
? !noArgListener.equals(that.noArgListener)
: that.noArgListener != null) {
return false;
}
if (oneArgListener != null
? !oneArgListener.equals(that.oneArgListener)
: that.oneArgListener != null) {
return false;
}
return true;
}
@Override
public int hashCode() {
int result = oneArgListener != null ? oneArgListener.hashCode() : 0;
result = 31 * result + (noArgListener != null
? noArgListener.hashCode()
: 0);
return result;
}
}