content: /*
   *  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 org.apache.causeway.extensions.fullcalendar.wkt.integration.fc.callback;
  
  import org.apache.wicket.Component;
  import org.apache.wicket.ajax.attributes.AjaxCallListener;
  
  /**
   * Prevents multiple clicks while ajax request is executing. We keep a variable that is set to {@code true} while the
   * request is running and to any other value when its done.
   */
  public class BlockingDecorator extends AjaxCallListener {
  
      private static final long serialVersionUID = 1L;
  
  	private static String clean(final String str) {
  		return str != null ? str.replaceAll("[^0-9a-zA-Z]", "") : null;
  	}
  
  	private String var(final Component component) {
  		if (!component.getOutputMarkupId()) {
  			throw new IllegalStateException();
  		}
  		// Calling clean() ensures that no Javascript operators (+, -, etc) are accidentally
  		// used in the markup id, which breaks this functionality.
  		String id = clean(component.getMarkupId());
  		return "window.wicketblock" + id;
  
  	}
  
  	@Override
  	public CharSequence getPrecondition(final Component component) {
  		// before we allow the request we check if one is already running by checking the var
  
  		// return false if the var is set to true (request running)
  		return var(component) + "!==true;";
  	}
  
  	@Override
  	public CharSequence getBeforeSendHandler(final Component component) {
  		// just before we start the request, we set the var to true
  		return var(component) + "=true;";
  	}
  
  	@Override
  	public CharSequence getCompleteHandler(final Component component) {
  		// when the request is complete we set the var to false
  		return var(component) + "=false;";
  	}
  }
  