/**
* **** BEGIN LICENSE BLOCK *****
* Version: CPL 1.0/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Common Public
* License Version 1.0 (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.eclipse.org/legal/cpl-v10.html
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* Copyright (C) 2009-2011 Yoko Harada <yokolet@gmail.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the CPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the CPL, the GPL or the LGPL.
* **** END LICENSE BLOCK *****
*/
package org.jruby.embed.variable;
import org.jruby.embed.internal.BiVariableMap;
import java.util.List;
import org.jruby.RubyClass;
import org.jruby.RubyModule;
import org.jruby.RubyObject;
import org.jruby.runtime.builtin.IRubyObject;
/**
* An implementation of BiVariable for a Ruby class variable.
*
* @author Yoko Harada <yokolet@gmail.com>
*/
public class ClassVariable extends AbstractVariable {
private static String pattern = "@@([a-zA-Z]|_)([a-zA-Z]|_|\\d)*";
/**
* Returns an instance of this class. This factory method is used when a class
* variables is put in {@link BiVariableMap}. This variable is originated from Java.
*
* @param runtime
* @param name a variable name
* @param javaObject Java object that should be assigned to.
* @return the instance of ClassVariable
*/
public static BiVariable getInstance(RubyObject receiver, String name, Object... javaObject) {
if (name.matches(pattern)) {
return new ClassVariable(receiver, name, javaObject);
}
return null;
}
/**
* Constructor when the variable is originated from Java
*
* @param receiver
* @param name
* @param javaObject
*/
private ClassVariable(RubyObject receiver, String name, Object... javaObjects) {
super(receiver, name, false);
updateByJavaObject(receiver.getRuntime(), javaObjects);
}
/**
* A constructor used when this variable is retrieved from Ruby.
*
* @param receiver a receiver object that this variable/constant is originally in. When
* the variable/constant is originated from Ruby, receiver may not be null.
* @param name the class variable name
* @param irubyObject Ruby class variable object
*/
ClassVariable(IRubyObject receiver, String name, IRubyObject irubyObject) {
super(receiver, name, true, irubyObject);
}
/**
* Retrieves class variables from Ruby after the evaluation.
*
* @param runtime Ruby runtime
* @param receiver receiver object returned when a script is evaluated.
* @param vars map to save retrieved class variables.
*/
public static void retrieve(RubyObject receiver, BiVariableMap vars) {
if (vars.isLazy()) return;
// trying to get variables from receiver;
updateClassVar(receiver, vars);
// trying to get variables from topself.
RubyObject topSelf = (RubyObject) receiver.getRuntime().getTopSelf();
updateClassVar(topSelf, vars);
}
private static void updateClassVar(RubyObject receiver, BiVariableMap vars) {
List<String> keys = receiver.getMetaClass().getClassVariableNameList();
for (String key : keys) {
IRubyObject value = receiver.getMetaClass().getClassVar(key);
BiVariable var = vars.getVariable(receiver, key);
if (var != null) {
var.setRubyObject(value);
} else {
var = new ClassVariable(receiver, key, value);
vars.update(key, var);
}
}
}
/**
* Retrieves a class variable by key from Ruby runtime after the evaluation.
* This method is used when eager retrieval is off.
*
* @param receiver receiver object returned when a script is evaluated.
* @param vars map to save retrieved instance variables.
* @param key instace varible name
*/
public static void retrieveByKey(RubyObject receiver, BiVariableMap vars, String key) {
IRubyObject value = null;
if (receiver == receiver.getRuntime().getTopSelf()
&& receiver.getMetaClass().getClassVariableNameList().contains(key)) {
value = receiver.getMetaClass().getClassVar(key);
} else {
RubyClass klazz = receiver.getMetaClass();
if (klazz.fastHasClassVariable(key.intern())) {
value = klazz.fastGetClassVar(key.intern());
}
}
if (value == null) return;
BiVariable var = vars.getVariable(receiver, key);
if (var != null) {
var.setRubyObject(value);
} else {
var = new ClassVariable(receiver, key, value);
vars.update(key, var);
}
}
/**
* Returns enum type of this variable defined in {@link BiVariable}.
*
* @return this enum type, BiVariable.Type.ClassVariable.
*/
public Type getType() {
return Type.ClassVariable;
}
/**
* Returns true if the given name is a decent Ruby class variable. Unless
* returns false.
*
* @param name is a name to be checked.
* @return true if the given name is of a Ruby class variable.
*/
public static boolean isValidName(Object name) {
return isValidName(pattern, name);
}
/**
* Injects a class variable value to a parsed Ruby script. This method is
* invoked during EvalUnit#run() is executed.
*
* @param runtime is environment where a variable injection occurs
* @param receiver is the instance that will have variable injection.
*/
public void inject() {
RubyModule rubyClass = getRubyClass(receiver.getRuntime());
rubyClass.setClassVar(name, irubyObject);
}
/**
* Attempts to remove this variable from top self or receiver.
*
*/
public void remove() {
RubyModule rubyClass = getRubyClass(receiver.getRuntime());
rubyClass.removeClassVariable(name);
}
}