javax.faces.component.UIImportConstants Maven / Gradle / Ivy
Show all versions of jakarta.faces-api Show documentation
/*
* Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package javax.faces.component;
import javax.el.ValueExpression;
import javax.faces.view.ViewMetadata;
/**
*
*
* UIImportConstants imports a mapping of all constant field values of the given type in the current
* view.
*
* The {@link javax.faces.view.ViewDeclarationLanguage} implementation must cause an instance of this component to be
* placed in the view for each occurrence of an <f:importConstants /> element placed inside of an
* <f:metadata /> element. The user must place <f:metadata /> as a direct child of
* the UIViewRoot. The {@link ViewMetadata#createMetadataView(javax.faces.context.FacesContext)} must
* take care of actual task of importing the constants.
*
* Instances of this class participate in the regular JSF lifecycle, including on Ajax requests.
*
* The purpose of this component is to provide a mapping of all constant field values of the given type in the
* current view. Constant field values are all public static final fields of the given type. The map key
* represents the constant field name as String. The map value represents the actual constant field value.
* This works for classes, interfaces and enums.
*
* Usage
*
* The below constant fields:
*
*
* package com.example;
*
* public class Foo {
* public static final String FOO1 = "foo1";
* public static final String FOO2 = "foo2";
* }
*
*
*
* package com.example;
*
* public interface Bar {
* public static final String BAR1 = "bar1";
* public static final String BAR2 = "bar2";
* }
*
*
*
* package com.example;
*
* public enum Baz {
* BAZ1, BAZ2;
* }
*
*
* Can be imported as below:
*
*
* <f:metadata>
* <f:importConstants type="com.example.Foo" />
* <f:importConstants type="com.example.Bar" var="Barrr" />
* <f:importConstants type="com.example.Baz" />
* </f:metadata>
*
*
* And can be referenced as below:
*
*
* #{Foo.FOO1}, #{Foo.FOO2}, #{Barrr.BAR1}, #{Barrr.BAR2}, #{Baz.BAZ1}, #{Baz.BAZ2}
*
*
*
* <h:selectOneMenu value="#{bean.baz}" >
* <f:selectItems value="#{Baz}" />
* </h:selectOneMenu>
*
*
*
*
* @since 2.3
*/
public class UIImportConstants extends UIComponentBase {
// ---------------------------------------------------------------------------------------------- Manifest Constants
/**
*
* The standard component type for this component.
*
*/
public static final String COMPONENT_TYPE = "javax.faces.ImportConstants";
/**
*
* The standard component family for this component.
*
*/
public static final String COMPONENT_FAMILY = "javax.faces.ImportConstants";
/**
* Properties that are tracked by state saving.
*/
enum PropertyKeys {
type, var;
}
// ---------------------------------------------------------------------------------------------------- Constructors
/**
*
* Create a new {@link UIImportConstants} instance with renderer type set to null.
*
*/
public UIImportConstants() {
setRendererType(null);
}
// ------------------------------------------------------------------------------------------------------ Properties
@Override
public String getFamily() {
return COMPONENT_FAMILY;
}
/**
*
* Returns the fully qualified name of the type to import the constant field values for.
*
*
* @return The fully qualified name of the type to import the constant field values for.
*/
public String getType() {
return (String) getStateHelper().eval(PropertyKeys.type);
}
/**
*
* Sets the fully qualified name of the type to import the constant field values for.
*
*
* @param type The fully qualified name of the type to import the constant field values for.
*/
public void setType(final String type) {
getStateHelper().put(PropertyKeys.type, type);
}
/**
*
* Returns name of request scope attribute under which constants will be exposed as a Map.
*
*
* @return Name of request scope attribute under which constants will be exposed as a Map.
*/
public String getVar() {
return (String) getStateHelper().eval(PropertyKeys.var);
}
/**
*
* Sets name of request scope attribute under which constants will be exposed as a Map.
*
*
* @param var Name of request scope attribute under which constants will be exposed as a Map.
*/
public void setVar(final String var) {
getStateHelper().put(PropertyKeys.var, var);
}
// --------------------------------------------------------------------------------------------- UIComponent Methods
/**
*
* Set the {@link ValueExpression} used to calculate the value for the specified attribute or property name, if any.
* If a {@link ValueExpression} is set for the var property, throw an illegal argument exception.
*
*
* @throws IllegalArgumentException If name is one of id, parent, or
* var.
* @throws NullPointerException If name is null.
*/
@Override
public void setValueExpression(String name, ValueExpression binding) {
if (PropertyKeys.var.toString().equals(name)) {
throw new IllegalArgumentException(name);
}
super.setValueExpression(name, binding);
}
}