freemarker.core.NewBI Maven / Gradle / Ivy
/*
* 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 freemarker.core;
import java.util.List;
import freemarker.ext.beans.BeanModel;
import freemarker.ext.beans.BeansWrapper;
import freemarker.template.ObjectWrapper;
import freemarker.template.Template;
import freemarker.template.TemplateException;
import freemarker.template.TemplateMethodModelEx;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelException;
/**
* A built-in that allows us to instantiate an instance of a java class.
* Usage is something like: <#assign foobar = "foo.bar.MyClass"?new()>;
*/
class NewBI extends BuiltIn {
static Class JYTHON_MODEL_CLASS;
static {
try {
JYTHON_MODEL_CLASS = Class.forName("freemarker.ext.jython.JythonModel");
} catch (Throwable e) {
JYTHON_MODEL_CLASS = null;
}
}
@Override
TemplateModel _eval(Environment env)
throws TemplateException {
return new ConstructorFunction(target.evalAndCoerceToPlainText(env), env, target.getTemplate());
}
class ConstructorFunction implements TemplateMethodModelEx {
private final Class cl;
private final Environment env;
public ConstructorFunction(String classname, Environment env, Template template) throws TemplateException {
this.env = env;
cl = env.getNewBuiltinClassResolver().resolve(classname, env, template);
if (!TemplateModel.class.isAssignableFrom(cl)) {
throw new _MiscTemplateException(NewBI.this, env,
"Class ", cl.getName(), " does not implement freemarker.template.TemplateModel");
}
if (BeanModel.class.isAssignableFrom(cl)) {
throw new _MiscTemplateException(NewBI.this, env,
"Bean Models cannot be instantiated using the ?", key, " built-in");
}
if (JYTHON_MODEL_CLASS != null && JYTHON_MODEL_CLASS.isAssignableFrom(cl)) {
throw new _MiscTemplateException(NewBI.this, env,
"Jython Models cannot be instantiated using the ?", key, " built-in");
}
}
public Object exec(List arguments) throws TemplateModelException {
ObjectWrapper ow = env.getObjectWrapper();
BeansWrapper bw =
ow instanceof BeansWrapper
? (BeansWrapper) ow
: BeansWrapper.getDefaultInstance();
return bw.newInstance(cl, arguments);
}
}
}