freemarker.core.Interpret Maven / Gradle / Ivy
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/*
* Copyright 2014 Attila Szegedi, Daniel Dekany, Jonathan Revusky
*
* 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 freemarker.core;
import java.io.IOException;
import java.io.Writer;
import java.util.Map;
import freemarker.template.Template;
import freemarker.template.TemplateException;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelException;
import freemarker.template.TemplateScalarModel;
import freemarker.template.TemplateSequenceModel;
import freemarker.template.TemplateTransformModel;
/**
* A method that takes a parameter and evaluates it as a scalar,
* then treats that scalar as template source code and returns a
* transform model that evaluates the template in place.
* The template inherits the configuration and environment of the executing
* template. By default, its name will be equal to
* executingTemplate.getName() + "$anonymous_interpreted". You can
* specify another parameter to the method call in which case the
* template name suffix is the specified id instead of "anonymous_interpreted".
*/
class Interpret extends BuiltIn
{
/**
* Constructs a template on-the-fly and returns it embedded in a
* {@link TemplateTransformModel}.
*
* The built-in has two arguments:
* the arguments passed to the method. It can receive at
* least one and at most two arguments, both must evaluate to a scalar.
* The first scalar is interpreted as a template source code and a template
* is built from it. The second (optional) is used to give the generated
* template a name.
*
* @return a {@link TemplateTransformModel} that when executed inside
* a <transform> block will process the generated template
* just as if it had been <transform>-ed at that point.
*/
TemplateModel _eval(Environment env)
throws TemplateException
{
TemplateModel model = target.eval(env);
Expression sourceExpr = null;
String id = "anonymous_interpreted";
if(model instanceof TemplateSequenceModel)
{
sourceExpr = ((Expression)new DynamicKeyName(target, new NumberLiteral(new Integer(0))).copyLocationFrom(target));
if(((TemplateSequenceModel)model).size() > 1)
{
id = ((Expression)new DynamicKeyName(target, new NumberLiteral(new Integer(1))).copyLocationFrom(target)).evalAndCoerceToString(env);
}
}
else if (model instanceof TemplateScalarModel)
{
sourceExpr = target;
}
else
{
throw new UnexpectedTypeException(
target, model,
"sequence or string", new Class[] { TemplateSequenceModel.class, TemplateScalarModel.class },
env);
}
String templateSource = sourceExpr.evalAndCoerceToString(env);
Template parentTemplate = env.getTemplate();
final Template interpretedTemplate;
try
{
interpretedTemplate = new Template(
(parentTemplate.getName() != null ? parentTemplate.getName() : "nameless_template") + "->" + id,
templateSource,
parentTemplate.getConfiguration());
}
catch(IOException e)
{
throw new _MiscTemplateException(this, e, env, new Object[] {
"Template parsing with \"?", key, "\" has failed with this error:\n\n",
MessageUtil.EMBEDDED_MESSAGE_BEGIN,
new _DelayedGetMessage(e),
MessageUtil.EMBEDDED_MESSAGE_END,
"\n\nThe failed expression:" });
}
interpretedTemplate.setLocale(env.getLocale());
return new TemplateProcessorModel(interpretedTemplate);
}
private class TemplateProcessorModel
implements
TemplateTransformModel
{
private final Template template;
TemplateProcessorModel(Template template)
{
this.template = template;
}
public Writer getWriter(final Writer out, Map args) throws TemplateModelException, IOException
{
try
{
Environment env = Environment.getCurrentEnvironment();
boolean lastFIRE = env.setFastInvalidReferenceExceptions(false);
try {
env.include(template);
} finally {
env.setFastInvalidReferenceExceptions(lastFIRE);
}
}
catch(Exception e)
{
throw new _TemplateModelException(e, new Object[] {
"Template created with \"?", key, "\" has stopped with this error:\n\n",
MessageUtil.EMBEDDED_MESSAGE_BEGIN,
new _DelayedGetMessage(e),
MessageUtil.EMBEDDED_MESSAGE_END });
}
return new Writer(out)
{
public void close()
{
}
public void flush() throws IOException
{
out.flush();
}
public void write(char[] cbuf, int off, int len) throws IOException
{
out.write(cbuf, off, len);
}
};
}
}
}