| // Copyright 2004 The Apache Software Foundation |
| // |
| // 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.apache.tapestry.engine; |
| |
| import java.io.IOException; |
| |
| import javax.servlet.ServletException; |
| |
| import org.apache.tapestry.ApplicationRuntimeException; |
| import org.apache.tapestry.IComponent; |
| import org.apache.tapestry.IExternalPage; |
| import org.apache.tapestry.IRequestCycle; |
| import org.apache.tapestry.Tapestry; |
| import org.apache.tapestry.request.ResponseOutputStream; |
| |
| /** |
| * The external service enables external applications |
| * to reference Tapestry pages via a URL. Pages which can be referenced |
| * by the external service must implement the {@link IExternalPage} |
| * interface. The external service enables the bookmarking of pages. |
| * |
| * <p> |
| * The external service may also be used by the Tapestry JSP taglibrary |
| * ({@link org.apache.tapestry.jsp.ExternalURLTag} and {@link org.apache.tapestry.jsp.ExternalTag}). |
| * |
| * <p> |
| * You can try and second guess the URL format used by Tapestry. |
| * The default URL format for the external service is: |
| * <blockquote> |
| * <tt>http://localhost/app?service=external/<i>[Page Name]</i>&sp=[Param 0]&sp=[Param 1]...</tt> |
| * </blockquote> |
| * For example to view the "ViewCustomer" page the service parameters 5056 (customer ID) and |
| * 309 (company ID) the external service URL would be: |
| * <blockquote> |
| * <tt>http://localhost/myapp?service=external&context=<b>ViewCustomer</b>&sp=<b>5056</b>&sp=<b>302</b></tt> |
| * </blockquote> |
| * In this example external service will get a "ViewCustomer" page and invoke the |
| * {@link IExternalPage#activateExternalPage(Object[], IRequestCycle)} method with the parameters: |
| * Object[] { new Integer(5056), new Integer(302) }. |
| * <p> |
| * Note service parameters (sp) need to be prefixed by valid |
| * {@link org.apache.tapestry.util.io.DataSqueezer} adaptor char. These adaptor chars are automatically provided in |
| * URL's created by the <tt>buildGesture()</tt> method. However if you hand coded an external |
| * service URL you will need to ensure valid prefix chars are present. |
| * <p> |
| * <table border="1" cellpadding="2"> |
| * <tr> |
| * <th>Prefix char(s)</th><th>Mapped Java Type</th> |
| * </tr> |
| * <tr> |
| * <td> TF</td><td> boolean</td> |
| * </tr> |
| * <tr> |
| * <td> b</td><td> byte</td> |
| * </tr> |
| * <tr> |
| * <td> c</td><td> char</td> |
| * </tr> |
| * <tr> |
| * <td> d</td><td> double</td> |
| * </tr> |
| * <tr> |
| * <td> -0123456789</td><td> integer</td> |
| * </tr> |
| * <tr> |
| * <td> l</td><td> long</td> |
| * </tr> |
| * <tr> |
| * <td> S</td><td> String</td> |
| * </tr> |
| * <tr> |
| * <td> s</td><td> short</td> |
| * </tr> |
| * <tr> |
| * <td> other chars</td> |
| * <td> <tt>String</tt> without truncation of first char</td> |
| * </tr> |
| * <table> |
| * <p> |
| * <p> |
| * A good rule of thumb is to keep the information encoded in the URL short and simple, and restrict it |
| * to just Strings and Integers. Integers can be encoded as-is. Prefixing all Strings with the letter 'S' |
| * will ensure that they are decoded properly. Again, this is only relevant if an |
| * {@link org.apache.tapestry.IExternalPage} is being referenced from static HTML or JSP and the |
| * URL must be assembled in user code ... when the URL is generated by Tapestry, it is automatically |
| * created with the correct prefixes and encodings (as with any other service). |
| * |
| * @see org.apache.tapestry.IExternalPage |
| * @see org.apache.tapestry.jsp.ExternalTag |
| * @see org.apache.tapestry.jsp.ExternalURLTag |
| * |
| * @author Howard Lewis Ship |
| * @author Malcolm Edgar |
| * @since 2.2 |
| * |
| **/ |
| |
| public class ExternalService extends AbstractService |
| { |
| |
| /** |
| * Builds a URL for a service. This is performed during the |
| * rendering phase of one request cycle and bulds URLs that will |
| * invoke activity in a subsequent request cycle. |
| * |
| * @param cycle Defines the request cycle being processed. |
| * @param component The component requesting the URL. Generally, the |
| * service context is established from the component. |
| * @param parameters Additional parameters specific to the |
| * component requesting the EngineServiceLink. |
| * @return The URL for the service. The URL always be encoded when it is returned. |
| * |
| **/ |
| |
| public ILink getLink(IRequestCycle cycle, IComponent component, Object[] parameters) |
| { |
| if (parameters == null || parameters.length == 0) |
| throw new ApplicationRuntimeException( |
| Tapestry.format("service-requires-parameters", Tapestry.EXTERNAL_SERVICE)); |
| |
| String pageName = (String) parameters[0]; |
| String[] context = new String[] { pageName }; |
| |
| Object[] pageParameters = new Object[parameters.length - 1]; |
| System.arraycopy(parameters, 1, pageParameters, 0, parameters.length - 1); |
| |
| return constructLink(cycle, Tapestry.EXTERNAL_SERVICE, context, pageParameters, true); |
| } |
| |
| public void service( |
| IEngineServiceView engine, |
| IRequestCycle cycle, |
| ResponseOutputStream output) |
| throws ServletException, IOException |
| { |
| IExternalPage page = null; |
| |
| String[] context = getServiceContext(cycle.getRequestContext()); |
| |
| if (context == null || context.length != 1) |
| throw new ApplicationRuntimeException( |
| Tapestry.format("service-single-context-parameter", Tapestry.EXTERNAL_SERVICE)); |
| |
| String pageName = context[0]; |
| |
| try |
| { |
| page = (IExternalPage) cycle.getPage(pageName); |
| } |
| catch (ClassCastException ex) |
| { |
| throw new ApplicationRuntimeException( |
| Tapestry.format("ExternalService.page-not-compatible", pageName), |
| ex); |
| } |
| |
| Object[] parameters = getParameters(cycle); |
| |
| cycle.setServiceParameters(parameters); |
| |
| cycle.activate(page); |
| |
| page.activateExternalPage(parameters, cycle); |
| |
| // Render the response. |
| engine.renderResponse(cycle, output); |
| } |
| |
| public String getName() |
| { |
| return Tapestry.EXTERNAL_SERVICE; |
| } |
| } |