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/*
 * 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.io.IOException;
import java.io.StringReader;
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;
import freemarker.template._VersionInts;


/**
 * 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 OutputFormatBoundBuiltIn {
    
    /**
     * 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. */ @Override protected TemplateModel calculateResult(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(Integer.valueOf(0))).copyLocationFrom(target)); if (((TemplateSequenceModel) model).size() > 1) { id = ((Expression) new DynamicKeyName(target, new NumberLiteral(Integer.valueOf(1))).copyLocationFrom(target)).evalAndCoerceToPlainText(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.evalAndCoerceToPlainText(env); Template parentTemplate = env.getConfiguration().getIncompatibleImprovements().intValue() >= _VersionInts.V_2_3_26 ? env.getCurrentTemplate() : env.getTemplate(); final Template interpretedTemplate; try { ParserConfiguration pCfg = parentTemplate.getParserConfiguration(); // pCfg.outputFormat is exceptional: it's inherited from the lexical context if (pCfg.getOutputFormat() != outputFormat) { pCfg = new _ParserConfigurationWithInheritedFormat( pCfg, outputFormat, Integer.valueOf(autoEscapingPolicy)); } interpretedTemplate = new Template( (parentTemplate.getName() != null ? parentTemplate.getName() : "nameless_template") + "->" + id, null, new StringReader(templateSource), parentTemplate.getConfiguration(), pCfg, null); } 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; } @Override 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, "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) { @Override public void close() { } @Override public void flush() throws IOException { out.flush(); } @Override public void write(char[] cbuf, int off, int len) throws IOException { out.write(cbuf, off, len); } }; } } }





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