/*
* $Id: Attribute.java 788065 2009-06-24 16:05:28Z apetrelli $
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.tiles;
import static org.apache.tiles.CompareUtil.*;
import java.io.Serializable;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
/**
* Common implementation of attribute definition.
*
* @version $Rev: 788065 $ $Date: 2009-06-24 18:05:28 +0200 (mer, 24 giu 2009) $
*/
public class Attribute implements Serializable, Cloneable {
/**
* The name of the template renderer.
*/
private static final String TEMPLATE_RENDERER = "template";
/**
* Attribute types.
*
* @deprecated Use {@link Attribute#setRenderer(String)} and
* {@link Attribute#getRenderer()}.
*/
public static enum AttributeType {
/**
* Attribute of type string.
*/
STRING("string"),
/**
* Attribute of type definition.
*/
DEFINITION("definition"),
/**
* Attribute of type template.
*/
TEMPLATE("template"),
/**
* Attribute of type object.
*/
OBJECT("object");
/**
* The string representation of the enum element.
*/
private String stringRepresentation;
/**
* Maps the string representation to the attribute type.
*/
private static Map<String, AttributeType> representation2type;
static {
representation2type = new HashMap<String, AttributeType>();
representation2type.put("string", AttributeType.STRING);
representation2type.put("definition", AttributeType.DEFINITION);
representation2type.put("template", AttributeType.TEMPLATE);
representation2type.put("object", AttributeType.OBJECT);
}
/**
* Returns the type for the given string representation.
*
* @param stringRepresentation The string representation of the needed
* type.
* @return The corresponding attribute type, if found, or
* <code>null</code> if not.
*/
public static AttributeType getType(String stringRepresentation) {
return representation2type.get(stringRepresentation);
}
/**
* Constructor.
*
* @param stringRepresentation The string representation of the enum
* element.
*/
private AttributeType(String stringRepresentation) {
this.stringRepresentation = stringRepresentation;
}
/**
* Returns the string representation of the element.
*
* @return The string representation.
*/
@Override
public String toString() {
return stringRepresentation;
}
};
/**
* The roles that can render this attribute.
* @since 2.0.6
*/
protected Set<String> roles = null;
/**
* The value of the attribute.
*/
protected Object value = null;
/**
* The expression to evaluate. Ignored if {@link #value} is not
* <code>null</code>.
*
* @since 2.1.2
* @deprecated Use {@link #expressionObject}.
*/
protected String expression = null;
/**
* The expression to evaluate. Ignored if {@link #value} is not
* <code>null</code>.
*
* @since 2.2.0
*/
protected Expression expressionObject = null;
/**
* The renderer name of the attribute. Default names are <code>string</code>,
* <code>template</code>, <code>definition</code>, <code>object</code>.
*/
private String renderer = null;
/**
* The name of the attribute. If it is <code>null</code>, it should be used
* as an element of a list attribute.
* @deprecated It is not used.
*/
@Deprecated
private String name = null;
/**
* Constructor.
*
*/
public Attribute() {
}
/**
* Constructor.
*
* @param value Object to store.
*/
public Attribute(Object value) {
this.value = value;
}
/**
* Copy constructor.
*
* @param attribute The attribute to copy from.
*/
public Attribute(Attribute attribute) {
this.name = attribute.name;
this.roles = attribute.roles;
this.value = attribute.getValue();
if (attribute.expressionObject != null) {
this.expressionObject = new Expression(attribute.expressionObject);
} else {
this.expressionObject = null;
}
this.renderer = attribute.renderer;
}
/**
* Constructor.
*
* @param name name of the attribute
* @param value Object to store.
*/
public Attribute(String name, Object value) {
this.name = name;
this.value = value;
}
/**
* Constructor.
*
* @param value Object to store.
* @param role Asociated role.
*/
public Attribute(Object value, String role) {
this.value = value;
setRole(role);
}
/**
* Constructor.
*
* @param value Object to store.
* @param role Associated role.
* @param type Attribute type.
* @deprecated Use {@link Attribute#Attribute(Object, String, String, String)}.
*/
@Deprecated
public Attribute(Object value, String role, AttributeType type) {
this.value = value;
setType(type);
setRole(role);
}
/**
* Constructor.
*
* @param value Object to store. If specified, the <code>expression</code>
* parameter will be ignored.
* @param expression The expression to be evaluated. Ignored if the
* <code>value</code> is not null.
* @param role Associated role.
* @param rendererName The renderer name.
* @since 2.1.2
* @deprecated Use {@link #Attribute(Object, Expression, String, String)}.
*/
public Attribute(Object value, String expression, String role, String rendererName) {
this(value, new Expression(expression), role, rendererName);
}
/**
* Constructor.
*
* @param value Object to store. If specified, the <code>expression</code>
* parameter will be ignored.
* @param expression The expression to be evaluated. Ignored if the
* <code>value</code> is not null.
* @param role Associated role.
* @param rendererName The renderer name.
* @since 2.2.0
*/
public Attribute(Object value, Expression expression, String role, String rendererName) {
this.value = value;
this.expressionObject = expression;
this.renderer = rendererName;
setRole(role);
}
/**
* Constructor.
*
* @param name name of the attribute
* @param value Object to store.
* @param role Asociated role.
* @param type Attribute type.
* @deprecated Use
* {@link Attribute#Attribute(Object, String, String, String)}.
*/
public Attribute(String name, Object value, String role,
AttributeType type) {
this.name = name;
this.value = value;
setType(type);
setRole(role);
}
/**
* Creates a template attribute, starting from the name of the template.
*
* @param template The template that will be rendered.
* @return The template attribute.
* @since 2.1.2
*/
public static Attribute createTemplateAttribute(String template) {
Attribute attribute = new Attribute();
attribute.setValue(template);
attribute.setRenderer(TEMPLATE_RENDERER);
return attribute;
}
/**
* Creates a template attribute, starting from the expression to evaluate to
* obtain the template.
*
* @param templateExpression The expression to evaluate.
* @return The template attribute.
* @since 2.1.2
*/
public static Attribute createTemplateAttributeWithExpression(
String templateExpression) {
Attribute attribute = new Attribute();
attribute.setExpressionObject(new Expression(templateExpression));
attribute.setRenderer(TEMPLATE_RENDERER);
return attribute;
}
/**
* Get role.
* @return the name of the required role(s)
*/
public String getRole() {
String retValue = null;
if (roles != null && !roles.isEmpty()) {
StringBuilder builder = new StringBuilder();
Iterator<String> roleIt = roles.iterator();
if (roleIt.hasNext()) {
builder.append(roleIt.next());
while (roleIt.hasNext()) {
builder.append(",");
builder.append(roleIt.next());
}
retValue = builder.toString();
}
}
return retValue;
}
/**
* Returns the roles that can render this attribute.
*
* @return The enabled roles.
* @since 2.0.6
*/
public Set<String> getRoles() {
return roles;
}
/**
* Set role.
*
* @param role Associated role.
*/
public void setRole(String role) {
if (role != null && role.trim().length() > 0) {
String[] rolesStrings = role.split("\\s*,\\s*");
roles = new HashSet<String>();
for (int i = 0; i < rolesStrings.length; i++) {
roles.add(rolesStrings[i]);
}
} else {
roles = null;
}
}
/**
* Sets the roles that can render this attribute.
*
* @param roles The enabled roles.
* @since 2.0.6
*/
public void setRoles(Set<String> roles) {
this.roles = roles;
}
/**
* Get value.
* @return the value
*/
public Object getValue() {
return value;
}
/**
* Set value.
*
* @param value New value.
*/
public void setValue(Object value) {
this.value = value;
}
/**
* Returns The expression to evaluate. Ignored if {@link #value} is not
* <code>null</code>.
*
* @return The expression to be evaluated.
* @since 2.1.2
* @deprecated Use {@link #getExpressionObject()}.
*/
public String getExpression() {
if (expressionObject != null) {
return expressionObject.getExpression();
}
return null;
}
/**
* Sets The expression to evaluate. Ignored if {@link #value} is not
* <code>null</code>.
*
* @param expression The expression to be evaluated.
* @since 2.1.2
* @deprecated Use {@link #setExpressionObject(Expression)}.
*/
public void setExpression(String expression) {
if (expression != null) {
expressionObject = new Expression(expression);
} else {
expressionObject = null;
}
}
/**
* Returns The expression to evaluate. Ignored if {@link #value} is not
* <code>null</code>.
*
* @return The expression to be evaluated.
* @since 2.2.0
*/
public Expression getExpressionObject() {
return expressionObject;
}
/**
* Sets The expression to evaluate. Ignored if {@link #value} is not
* <code>null</code>.
*
* @param expressionObject The expression to be evaluated.
* @since 2.2.0
*/
public void setExpressionObject(Expression expressionObject) {
this.expressionObject = expressionObject;
}
/** {@inheritDoc} */
public String toString() {
if (value != null) {
return value.toString();
}
return null;
}
/**
* Returns the type of this attribute.
*
* @return The attribute type. It can be <code>string</code>,
* <code>template</code>, <code>definition</code>, <code>object</code>.
* @deprecated Use {@link Attribute#getRenderer()}.
*/
public AttributeType getType() {
return AttributeType.getType(renderer);
}
/**
* Sets the type of this attribute.
*
* @param type The attribute type.
* @deprecated Use {@link Attribute#setRenderer(String)}.
*/
public void setType(AttributeType type) {
this.renderer = type.toString();
}
/**
* Returns the renderer name to use.
*
* @return The renderer name.
* @since 2.1.0
*/
public String getRenderer() {
return renderer;
}
/**
* Sets the renderer name to use.
*
* @param rendererName The renderer.
* @since 2.1.0
*/
public void setRenderer(String rendererName) {
this.renderer = rendererName;
}
/**
* Returns the name of the attribute.
*
* @return The name of the attribute. It can be <code>null</code>, but in
* this case it should be used as an element of <code>ListAttribute</code>
* @deprecated Use the <code>getName</code> methods in object that contain
* attributes.
*/
@Deprecated
public String getName() {
return name;
}
/**
* Sets the name of the attribute.
*
* @param name The name of the attribute. It can be <code>null</code>,
* but in this case it should be used as an element of
* <code>ListAttribute</code>
* @deprecated Use the <code>setName</code> methods in object that contain
* attributes.
*/
@Deprecated
public void setName(String name) {
this.name = name;
}
/**
* Sets the body of this attribute.
*
* @param body The attribute body.
*/
// FIXME Is it necessary?
public void setBody(String body) {
if (body != null && body.length() != 0) {
setValue(body);
}
}
/**
* Inherits an attribute, i.e. overwrites null properties with the ones
* provided by the attribute.
*
* @param attribute The attribute to inherit.
* @since 2.1.2
*/
public void inherit(Attribute attribute) {
if (value == null) {
value = attribute.getValue();
}
Expression targetExpressionObject = attribute.getExpressionObject();
if (targetExpressionObject != null
&& (expressionObject == null || expressionObject
.getExpression() == null)) {
expressionObject = new Expression(targetExpressionObject);
}
if (roles == null || roles.isEmpty()) {
roles = attribute.getRoles();
}
if (renderer == null) {
renderer = attribute.getRenderer();
}
}
/** {@inheritDoc} */
@Override
public boolean equals(Object obj) {
Attribute attribute = (Attribute) obj;
return nullSafeEquals(value, attribute.value)
&& nullSafeEquals(renderer, attribute.renderer)
&& nullSafeEquals(roles, attribute.roles)
&& nullSafeEquals(expressionObject, attribute.expressionObject);
}
/** {@inheritDoc} */
@Override
public int hashCode() {
return nullSafeHashCode(value) + nullSafeHashCode(renderer)
+ nullSafeHashCode(roles) + nullSafeHashCode(expressionObject);
}
/** {@inheritDoc} */
@Override
public Attribute clone() {
return new Attribute(this);
}
}
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