    001// Copyright 2006, 2007, 2008, 2010 The Apache Software Foundation
    002//
    003// Licensed under the Apache License, Version 2.0 (the "License");
    004// you may not use this file except in compliance with the License.
    005// You may obtain a copy of the License at
    006//
    007// http://www.apache.org/licenses/LICENSE-2.0
    008//
    009// Unless required by applicable law or agreed to in writing, software
    010// distributed under the License is distributed on an "AS IS" BASIS,
    011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012// See the License for the specific language governing permissions and
    013// limitations under the License.
    014
    015package org.apache.tapestry5.runtime;
    016
    017import org.apache.tapestry5.ComponentResourcesCommon;
    018import org.apache.tapestry5.EventContext;
    019
    020/**
    021 * An event that may originate in application logic, or as a result of a client interaction (a GET or POST from the
    022 * client).
    023 *
    024 * @see ComponentResourcesCommon#triggerEvent(String, Object[], org.apache.tapestry5.ComponentEventCallback)
    025 * @see org.apache.tapestry5.ComponentEventCallback
    026 */
    027public interface ComponentEvent extends Event
    028{
    029    /**
    030     * Returns true if the event matches the provided criteria and the event has not yet been aborted.
    031     *
    032     * @param eventType
    033     *            the type of event (case insensitive match)
    034     * @param componentId
    035     *            component is to match against (case insensitive), or the empty string
    036     * @param parameterCount
    037     *            minimum number of context values
    038     * @return true if the event matches (and has not yet been aborted)
    039     */
    040    boolean matches(String eventType, String componentId, int parameterCount);
    041
    042    /**
    043     * Returns true if the event matches the provided criteria and the event has not yet been aborted.
    044     *
    045     * @param eventType
    046     *            the type of event (case insensitive match)
    047     * @param componentId
    048     *            component is to match against (case insensitive), or the empty string
    049     * @param parameterCount
    050     *            minimum number of context values
    051     * @param staticActivationContextValues
    052     *            a String array. If null, there are no static activation context values. If
    053     *            any value in the array is null, it's considered dynamic and ignored.
    054     *            I any value in the arra isn't null, it's compared to the corresponding
    055     *            activation context value. If it doesn't match, this method will return null.
    056     * @return true if the event matches (and has not yet been aborted)
    057     * @since 5.8.0
    058     */
    059    default boolean matches(String eventType, String componentId, int parameterCount, String[] staticActivationContextValues)
    060    {
    061        boolean matches = matches(eventType, componentId, parameterCount);
    062        if (matches && staticActivationContextValues != null)
    063        {
    064            for (int i = 0; i < staticActivationContextValues.length; i++)
    065            {
    066                if (staticActivationContextValues[i] != null &&
    067                        !staticActivationContextValues[i].equals(getEventContext().get(String.class, i)))
    068                {
    069                    matches = false;
    070                    break;
    071                }
    072            }
    073        }
    074        return matches;
    075    }
    076
    077    /**
    078     * Coerces a context value to a particular type. The context is an array of objects; typically it is an array of
    079     * strings of extra path information encoded into the action URL.
    080     *
    081     * @param index
    082     *            the index of the context value
    083     * @param desiredTypeName
    084     *            the desired type
    085     * @return the coerced value (a wrapper type if the desired type is a primitive)
    086     */
    087    Object coerceContext(int index, String desiredTypeName);
    088
    089    /**
    090     * Returns the underlying {@link org.apache.tapestry5.EventContext} as a (possibly empty) array.
    091     */
    092    Object[] getContext();
    093
    094    /**
    095     * Returns the underlying event context.
    096     */
    097    EventContext getEventContext();
    098}