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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.template.utility;

import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.Map;

import freemarker.core.Environment;
import freemarker.ext.util.WrapperTemplateModel;
import freemarker.template.AdapterTemplateModel;
import freemarker.template.ObjectWrapper;
import freemarker.template.TemplateBooleanModel;
import freemarker.template.TemplateCollectionModel;
import freemarker.template.TemplateDateModel;
import freemarker.template.TemplateHashModelEx;
import freemarker.template.TemplateHashModelEx2;
import freemarker.template.TemplateHashModelEx2.KeyValuePair;
import freemarker.template.TemplateHashModelEx2.KeyValuePairIterator;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelException;
import freemarker.template.TemplateModelIterator;
import freemarker.template.TemplateNumberModel;
import freemarker.template.TemplateScalarModel;
import freemarker.template.TemplateSequenceModel;

/**
 * Utility methods for unwrapping {@link TemplateModel}-s.
 */
public class DeepUnwrap {
    private static final Class OBJECT_CLASS = Object.class;
    /**
     * Unwraps {@link TemplateModel}-s recursively.
     * The converting of the {@link TemplateModel} object happens with the following rules:
     * 
    *
  1. If the object implements {@link AdapterTemplateModel}, then the result * of {@link AdapterTemplateModel#getAdaptedObject(Class)} for Object.class is returned. *
  2. If the object implements {@link WrapperTemplateModel}, then the result * of {@link WrapperTemplateModel#getWrappedObject()} is returned. *
  3. If the object is identical to the null model of the current object * wrapper, null is returned. *
  4. If the object implements {@link TemplateScalarModel}, then the result * of {@link TemplateScalarModel#getAsString()} is returned. *
  5. If the object implements {@link TemplateNumberModel}, then the result * of {@link TemplateNumberModel#getAsNumber()} is returned. *
  6. If the object implements {@link TemplateDateModel}, then the result * of {@link TemplateDateModel#getAsDate()} is returned. *
  7. If the object implements {@link TemplateBooleanModel}, then the result * of {@link TemplateBooleanModel#getAsBoolean()} is returned. *
  8. If the object implements {@link TemplateSequenceModel} or * {@link TemplateCollectionModel}, then a java.util.ArrayList is * constructed from the subvariables, and each subvariable is unwrapped with * the rules described here (recursive unwrapping). *
  9. If the object implements {@link TemplateHashModelEx}, then a * java.util.HashMap is constructed from the subvariables, and each * subvariable is unwrapped with the rules described here (recursive unwrapping). *
  10. Throw a TemplateModelException, because it doesn't know how to * unwrap the object. *
*/ public static Object unwrap(TemplateModel model) throws TemplateModelException { return unwrap(model, false); } /** * Same as {@link #unwrap(TemplateModel)}, but it doesn't throw exception * if it doesn't know how to unwrap the model, but rather returns it as-is. * @since 2.3.14 */ public static Object permissiveUnwrap(TemplateModel model) throws TemplateModelException { return unwrap(model, true); } /** * @deprecated the name of this method is mistyped. Use * {@link #permissiveUnwrap(TemplateModel)} instead. */ @Deprecated public static Object premissiveUnwrap(TemplateModel model) throws TemplateModelException { return unwrap(model, true); } private static Object unwrap(TemplateModel model, boolean permissive) throws TemplateModelException { Environment env = Environment.getCurrentEnvironment(); TemplateModel nullModel = null; if (env != null) { ObjectWrapper wrapper = env.getObjectWrapper(); if (wrapper != null) { nullModel = wrapper.wrap(null); } } return unwrap(model, nullModel, permissive); } private static Object unwrap(TemplateModel model, TemplateModel nullModel, boolean permissive) throws TemplateModelException { if (model instanceof AdapterTemplateModel) { return ((AdapterTemplateModel) model).getAdaptedObject(OBJECT_CLASS); } if (model instanceof WrapperTemplateModel) { return ((WrapperTemplateModel) model).getWrappedObject(); } if (model == nullModel) { return null; } if (model instanceof TemplateScalarModel) { return ((TemplateScalarModel) model).getAsString(); } if (model instanceof TemplateNumberModel) { return ((TemplateNumberModel) model).getAsNumber(); } if (model instanceof TemplateDateModel) { return ((TemplateDateModel) model).getAsDate(); } if (model instanceof TemplateBooleanModel) { return Boolean.valueOf(((TemplateBooleanModel) model).getAsBoolean()); } if (model instanceof TemplateSequenceModel) { TemplateSequenceModel seq = (TemplateSequenceModel) model; int size = seq.size(); ArrayList list = new ArrayList(size); for (int i = 0; i < size; ++i) { list.add(unwrap(seq.get(i), nullModel, permissive)); } return list; } if (model instanceof TemplateCollectionModel) { TemplateCollectionModel coll = (TemplateCollectionModel) model; ArrayList list = new ArrayList(); TemplateModelIterator it = coll.iterator(); while (it.hasNext()) { list.add(unwrap(it.next(), nullModel, permissive)); } return list; } if (model instanceof TemplateHashModelEx) { TemplateHashModelEx hash = (TemplateHashModelEx) model; Map map = new LinkedHashMap<>(); if (model instanceof TemplateHashModelEx2) { KeyValuePairIterator kvps = ((TemplateHashModelEx2) model).keyValuePairIterator(); while (kvps.hasNext()) { KeyValuePair kvp = kvps.next(); map.put( unwrap(kvp.getKey(), nullModel, permissive), unwrap(kvp.getValue(), nullModel, permissive)); } } else { TemplateModelIterator keys = hash.keys().iterator(); while (keys.hasNext()) { String key = (String) unwrap(keys.next(), nullModel, permissive); map.put(key, unwrap(hash.get(key), nullModel, permissive)); } } return map; } if (permissive) { return model; } throw new TemplateModelException("Cannot deep-unwrap model of type " + model.getClass().getName()); } }




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