/*
* Copyright (C) 2010 Google Inc.
*
* 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 com.google.clearsilver.jsilver.values;
import com.google.clearsilver.jsilver.autoescape.EscapeMode;
import com.google.clearsilver.jsilver.data.Data;
import com.google.clearsilver.jsilver.data.DataContext;
import com.google.clearsilver.jsilver.data.TypeConverter;
/**
* A value linked to a variable reference. When this value is evaluated in an expression a Data
* object will be fetched from the provided DataContext and and its value returned or {@code null}
* if there is no Data object associated with the given name.
*
* @see Value
* @see Data
*/
public class VariableValue extends VariantValue {
// TODO: Make this non-public and come up with a smarter way
// for it to be used elsewhere without having to be used in a cast.
private final String name;
private final DataContext dataContext;
private boolean gotRef = false;
private Data reference;
public VariableValue(String name, DataContext dataContext) {
// VariableValues always have partiallyEscaped=false since they represent
// a Data object, not a compound expression containing escaping functions.
// We override getEscapeMode() to return the Data object's escape mode,
// so the mode we pass here is just ignored.
super(EscapeMode.ESCAPE_NONE, false);
this.dataContext = dataContext;
this.name = name;
}
public String getName() {
return name;
}
public Data getReference() {
if (!gotRef) {
reference = dataContext.findVariable(name, false);
gotRef = true;
}
return reference;
}
@Override
protected String value() {
Data data = getReference();
return data == null ? null : data.getValue();
}
@Override
public boolean exists() {
return TypeConverter.exists(getReference());
}
// Note we are not overriding asString as we want that to return the value
// of the node located at this address.
@Override
public String toString() {
return name;
}
@Override
public EscapeMode getEscapeMode() {
Data data = getReference();
if (data == null) {
return super.getEscapeMode();
}
return data.getEscapeMode();
}
}