001    // Copyright 2005 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    
015    package org.apache.tapestry.record;
016    
017    import org.apache.tapestry.IRequestCycle;
018    import org.apache.tapestry.engine.ServiceEncoding;
019    
020    /**
021     * Service tapestry.persist.ClientPropertyPersistenceScope. Determines whether a particular property
022     * needs to be persisted or not.
023     * 
024     * @author Mindbridge
025     * @since 4.0
026     * @see org.apache.tapestry.record.ClientPropertyPersistenceStrategy
027     */
028    public interface ClientPropertyPersistenceScope
029    {
030        /**
031         * Determines whether state should be encoded for the request.
032         * 
033         * @param encoding
034         *            identifies the service, URL and base set of parameters
035         * @param cycle
036         *            current request
037         * @param pageName
038         *            the page for which data is potentially to be encoded
039         * @param data
040         * @return true if state should be encoded into the encoding, false otherwise
041         */
042    
043        public boolean shouldEncodeState(ServiceEncoding encoding, IRequestCycle cycle,
044                String pageName, PersistentPropertyData data);
045    
046        /**
047         * Constructs a parameter name for a particular page name. The parameter name can be recognized
048         * (in a later request) by the {@link #isParameterForScope(String)} method.
049         * 
050         * @param pageName
051         *            the name of the page for which a corresponding parameter name should be generated.
052         * @returns a query parameter name that identifies the page and this client persistence scope.
053         */
054    
055        public String constructParameterName(String pageName);
056    
057        /**
058         * Checks a parameter to see if it was the result of {@link #constructParameterName(String)} for
059         * this persistence scope.
060         * 
061         * @param parameterName
062         *            a query parameter name
063         * @return true if the parameterName was genereted (i.e., is properly prefixed) by this scope,
064         *         false otherwise.
065         */
066    
067        public boolean isParameterForScope(String parameterName);
068    
069        /**
070         * Extracts a page name from a query parameter name.
071         * 
072         * @param parameterName
073         *            the paramter name, for which {@link #isParameterForScope(String) must return true
074         * @return the name of the page
075         */
076        public String extractPageName(String parameterName);
077    }