/**
* **** 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.RubyObject;
import org.jruby.runtime.builtin.IRubyObject;
import org.jruby.runtime.builtin.InstanceVariables;
/**
* An implementation of BiVariable for a Ruby instance variable.
*
* @author Yoko Harada <yokolet@gmail.com>
*/
public class InstanceVariable 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 an instance
* variable is put in {@link BiVariableMap}.
*
* @param runtime Ruby runtime
* @param name a variable name
* @param javaObject Java object that should be assigned to.
* @return the instance of InstanceVariable
*/
public static BiVariable getInstance(RubyObject receiver, String name, Object... javaObject) {
if (name.matches(pattern)) {
return new InstanceVariable(receiver, name, javaObject);
}
return null;
}
private InstanceVariable(RubyObject receiver, String name, Object... javaObjects) {
super(receiver, name, false);
updateByJavaObject(receiver.getRuntime(), javaObjects);
}
/**
* A constructor used when instance variables are 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 instance variable name
* @param irubyObject Ruby instance object
*/
public InstanceVariable(IRubyObject receiver, String name, IRubyObject irubyObject) {
super(receiver, name, true, irubyObject);
}
/**
* Retrieves instance 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 instance variables.
*/
public static void retrieve(RubyObject receiver, BiVariableMap vars) {
if (vars.isLazy()) return;
updateInstanceVar(receiver, vars);
updateInstanceVar((RubyObject)receiver.getRuntime().getTopSelf(), vars);
}
static void updateInstanceVar(RubyObject receiver, BiVariableMap vars) {
InstanceVariables ivars = receiver.getInstanceVariables();
List<String> keys = ivars.getInstanceVariableNameList();
for (String key : keys) {
IRubyObject value = ivars.getInstanceVariable(key);
BiVariable var = vars.getVariable(receiver, key);
if (var != null) {
var.setRubyObject(value);
} else {
var = new InstanceVariable(receiver, key, value);
vars.update(key, var);
}
}
}
/**
* Retrieves a instance 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) {
InstanceVariables ivars = receiver.getInstanceVariables();
// if the specified key doesn't exist, this method is called before the
// evaluation. Don't update value in this case.
if (!ivars.getInstanceVariableNameList().contains(key)) return;
// the specified key is found, so let's update
IRubyObject value = ivars.getInstanceVariable(key);
BiVariable var = vars.getVariable(receiver, key);
if (var != null) {
var.setRubyObject(value);
} else {
var = new InstanceVariable(receiver, key, value);
vars.update(key, var);
}
}
/**
* Returns enum type of this variable defined in {@link BiVariable}.
*
* @return this enum type, BiVariable.Type.InstanceVariable.
*/
public Type getType() {
return Type.InstanceVariable;
}
/**
* Returns true if the given name is a decent Ruby instance variable. Unless
* returns false.
*
* @param name is a name to be checked.
* @return true if the given name is of a Ruby instance variable.
*/
public static boolean isValidName(Object name) {
return isValidName(pattern, name);
}
/**
* Injects an instance 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() {
((RubyObject)receiver).setInstanceVariable(name.intern(), getRubyObject());
}
/**
* Attempts to remove this variable from top self or receiver.
*
*/
public void remove() {
((RubyObject)receiver).removeInstanceVariable(name);
}
}