| /* |
| * 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.template; |
| |
| import java.io.FilterWriter; |
| import java.io.IOException; |
| import java.io.Writer; |
| import java.util.Map; |
| |
| import freemarker.template.utility.DeepUnwrap; |
| |
| /** |
| * "transform" template language data type: user-defined directives |
| * (much like macros) specialized on filtering output; you should rather use the newer {@link TemplateDirectiveModel} |
| * instead. This interface will certainly be deprecated in FreeMarker 2.4. |
| */ |
| public interface TemplateTransformModel extends TemplateModel { |
| |
| /** |
| * Returns a writer that will be used by the engine to feed the transformation input to the transform. Each call to |
| * this method must return a new instance of the writer so that the transformation is thread-safe. |
| * <p> |
| * This method should not throw {@link RuntimeException}, nor {@link IOException} that wasn't caused by writing to |
| * the output. Such exceptions should be catched inside the method and wrapped inside a |
| * {@link TemplateModelException}. (Note that setting {@link Configuration#setWrapUncheckedExceptions(boolean)} to |
| * {@code true} can mitigate the negative effects of implementations that throw {@link RuntimeException}-s.) |
| * |
| * @param out |
| * the character stream to which to write the transformed output |
| * |
| * @param args |
| * the arguments (if any) passed to the transformation as a map of key/value pairs where the keys are |
| * strings and the arguments are {@link TemplateModel} instances. This is never {@code null}. (If you |
| * need to convert the template models to POJOs, you can use the utility methods in the |
| * {@link DeepUnwrap} class. Though it's recommended to work with {@link TemplateModel}-s directly.) |
| * |
| * @return The {@link Writer} to which the engine will write the content to transform, or {@code null} if the |
| * transform does not support nested content (body). The returned {@link Writer} may implements the |
| * {@link TransformControl} interface if it needs advanced control over the evaluation of the nested |
| * content. FreeMarker will call {@link Writer#close()} after the transform end-tag. {@link Writer#close()} |
| * must not close the {@link Writer} received as the {@code out} parameter (so if you are using a |
| * {@link FilterWriter}, you must override {@link FilterWriter#close()}, as by default that closes the |
| * wrapped {@link Writer}). Since 2.3.27 its also allowed to return the {@code out} writer as is, in which |
| * case it won't be closed. |
| * |
| * @throws TemplateModelException |
| * If any problem occurs that's not an {@link IOException} during writing the template output. |
| * @throws IOException |
| * When writing to {@code out} (the parameter) fails. Other {@link IOException}-s should be catched in |
| * this method and wrapped into {@link TemplateModelException}. |
| */ |
| Writer getWriter(Writer out, Map args) throws TemplateModelException, IOException; |
| } |