Permalink
Browse files

Added util component for looking up other components by their ID.

  • Loading branch information...
arjantijms committed Jul 4, 2014
1 parent 32113c7 commit 2286fd4cdd258cc4e6f461d0d7a906a6b2400f3b
@@ -0,0 +1,145 @@
/*
* Copyright 2014 OmniFaces.
*
* 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.omnifaces.component.util;
import static java.lang.String.format;
import static org.omnifaces.component.util.ResolveComponent.PropertyKeys.name;
import static org.omnifaces.component.util.ResolveComponent.PropertyKeys.scope;
import static org.omnifaces.util.Components.findComponentRelatively;
import static org.omnifaces.util.Events.subscribeToViewEvent;
import static org.omnifaces.util.Faces.isPostback;
import static org.omnifaces.util.Faces.setRequestAttribute;
import static org.omnifaces.util.Utils.isEmpty;
import javax.faces.component.FacesComponent;
import javax.faces.component.UIComponent;
import javax.faces.event.AbortProcessingException;
import javax.faces.event.ComponentSystemEvent;
import javax.faces.event.PostRestoreStateEvent;
import javax.faces.event.PreRenderViewEvent;
import javax.faces.event.SystemEvent;
import javax.faces.event.SystemEventListener;
import javax.faces.view.facelets.FaceletContext;
import org.omnifaces.el.ReadOnlyValueExpression;
import org.omnifaces.util.Callback.Returning;
import org.omnifaces.util.State;
/**
* <strong>ResolveComponent</strong> is a utility component via which a component can be looked up by its ID and
* a reference to it put in either the "facelet scope" (default) or the request scope.
*
* @since 2.0
* @author Arjan Tijms
*/
@FacesComponent(ResolveComponent.COMPONENT_TYPE)
public class ResolveComponent extends UtilFamily implements FaceletContextConsumer, SystemEventListener {
public static final String COMPONENT_TYPE = "org.omnifaces.component.util.ResolveComponent";
private static final String ERROR_COMPONENT_NOT_FOUND =
"A component with ID '%s' as specified by the 'for' attribute of the ResolveComponent with Id '%s' could not be found.";
public static final String DEFAULT_SCOPE = "facelet";
private UIComponent foundComponent;
private final State state = new State(getStateHelper());
enum PropertyKeys {
name, scope, /* for */
}
// Actions --------------------------------------------------------------------------------------------------------
@Override
public void setFaceletContext(FaceletContext faceletContext) {
if (getScope().equals("facelet")) {
faceletContext.getVariableMapper().setVariable(getName(), new ReadOnlyValueExpression(UIComponent.class, new Returning<Object>() { @Override public Object invoke() {
return foundComponent;
}}));
}
}
public ResolveComponent() {
if (!isPostback()) { // For an initial (GET) request, there's no restore state event and we use pre-render view
subscribeToViewEvent(PreRenderViewEvent.class, this);
}
}
@Override
public boolean isListenerForSource(Object source) {
return true;
}
@Override
public void processEvent(SystemEvent event) throws AbortProcessingException {
doProcess();
}
@Override
public void processEvent(ComponentSystemEvent event) throws AbortProcessingException {
if (event instanceof PostRestoreStateEvent) { // For a postback we use the post-restore state event
doProcess();
}
}
public void doProcess() {
String forValue = getFor();
if (!isEmpty(forValue)) {
UIComponent component = findComponentRelatively(this, forValue);
if (component == null) {
component = findComponent(forValue);
}
if (component == null) {
throw new IllegalArgumentException(format(ERROR_COMPONENT_NOT_FOUND, forValue, getId()));
}
foundComponent = component;
if (getScope().equals("request")) {
setRequestAttribute(getName(), foundComponent);
}
}
}
// Attribute getters/setters --------------------------------------------------------------------------------------
public String getName() {
return state.get(name);
}
public void setName(String nameValue) {
state.put(name, nameValue);
}
public String getFor() {
return state.get("for");
}
public void setFor(String nameValue) {
state.put("for", nameValue);
}
public String getScope() {
return state.get(scope, DEFAULT_SCOPE);
}
public void setScope(String scopeValue) {
state.put(scope, scopeValue);
}
}
@@ -0,0 +1,48 @@
/*
* Copyright 2014 OmniFaces.
*
* 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.omnifaces.component.util;
import javax.faces.component.UIComponentBase;
/**
* Base class which is to be shared between all components of the Util family.
*
* @author Arjan Tijms
* @since 2.0
*/
public abstract class UtilFamily extends UIComponentBase {
// Public constants -----------------------------------------------------------------------------------------------
/** The standard component family. */
public static final String COMPONENT_FAMILY = "org.omnifaces.component.util";
// UIComponent overrides ------------------------------------------------------------------------------------------
/**
* Returns {@link #COMPONENT_FAMILY}.
*/
@Override
public String getFamily() {
return COMPONENT_FAMILY;
}
/**
* Returns <code>true</code>.
*/
@Override
public boolean getRendersChildren() {
return true;
}
}
@@ -1961,6 +1961,55 @@ public class ValidateValuesBean implements MultiFieldValidator {
<type>java.lang.String</type>
</attribute>
</tag>
<tag>
<description>
<![CDATA[
<strong>ResolveComponent</strong> is a utility component via which a component can be looked up by its ID and
a reference to it put in either the "facelet scope" (default) or the request scope.
]]>
</description>
<tag-name>resolveComponent</tag-name>
<component>
<component-type>org.omnifaces.component.util.ResolveComponent</component-type>
<handler-class>org.omnifaces.taghandler.ComponentExtraHandler</handler-class>
</component>
<attribute>
<description>
<![CDATA[
Name under which the component will be made available to EL, scoped to the body of the Facelets tag (default)
or to the request.
]]>
</description>
<name>name</name>
<required>true</required>
<type>java.lang.String</type>
</attribute>
<attribute>
<description>
<![CDATA[
ID of the component that will be resolved (looked-up) and if found a reference of it made available to EL.
]]>
</description>
<name>for</name>
<required>true</required>
<type>java.lang.String</type>
</attribute>
<attribute>
<description>
<![CDATA[
Optional scope identifier used to set the scope in which the component reference is inserted. If no scope is specified,
the default scope "facelet" will be used.
<p>
Values values are "facelet" (default) and "request".
]]>
</description>
<name>scope</name>
<required>false</required>
<type>java.lang.String</type>
</attribute>
</tag>
<tag>
<description>

0 comments on commit 2286fd4

Please sign in to comment.