callbackutils.java

来自「exTreme taglib的使用」· Java 代码 · 共 75 行

/*
 * Copyright 2004 original author or authors.
 * 
 * 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 org.extremecomponents.table.callback;

import java.util.Collection;

import org.apache.commons.beanutils.PropertyUtils;
import org.apache.commons.lang.StringUtils;
import org.extremecomponents.table.bean.Table;
import org.extremecomponents.table.core.BaseModel;
import org.extremecomponents.util.ExtremeUtils;

/**
 * Deal with callback specific utils.
 * 
 * @author Jeff Johnston
 */
class CallbackUtils {

    private CallbackUtils() {
    }

    static Collection findCollection(BaseModel model, Table table)
            throws Exception {
        Collection collection = null;

        String items = String.valueOf(table.getItems());

        if (StringUtils.isBlank(items) || "null".equals(items)) {
            throw new Exception("The eXtremeComponent needs to have the items or collection attribute defined.");
        }

        if (StringUtils.contains(items, ".")) {
            String split[] = StringUtils.split(items, ".");
            Object obj = ExtremeUtils.retrieveFromScope(model.getPageContext(), split[0], table.getScope());
            String collectionToFind = StringUtils.substringAfter(items, ".");
            if (ExtremeUtils.isBeanPropertyReadable(obj, collectionToFind)) {
                obj = PropertyUtils.getProperty(obj, collectionToFind);
            }

            if (!(obj instanceof Collection)) {
                throw new Exception("The object passed into the eXtremeComponent is not of type Collection.");
            }

            collection = (Collection) obj;
        } else {
            Object obj = ExtremeUtils.retrieveFromScope(model.getPageContext(), items, table.getScope());
            if (obj instanceof Collection) {
                collection = (Collection) obj;
            } else {
                throw new Exception("The object passed into the eXtremeComponent is not of type Collection.");
            }
        }

        if (collection == null) {
            throw new Exception("The eXtremeComponent could not find the Collection of Beans (or Maps).");
        }

        return collection;
    }
}