| /* |
| * 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 javax.servlet.jsp.tagext; |
| |
| import java.util.Map; |
| |
| /** |
| * Translation-time validator class for a JSP page. |
| * A validator operates on the XML view associated with the JSP page. |
| * |
| * <p> |
| * The TLD file associates a TagLibraryValidator class and some init |
| * arguments with a tag library. |
| * |
| * <p> |
| * The JSP container is reponsible for locating an appropriate |
| * instance of the appropriate subclass by |
| * |
| * <ul> |
| * <li> new a fresh instance, or reuse an available one |
| * <li> invoke the setInitParams(Map) method on the instance |
| * </ul> |
| * |
| * once initialized, the validate(String, String, PageData) method will |
| * be invoked, where the first two arguments are the prefix |
| * and uri for this tag library in the XML View. The prefix is intended |
| * to make it easier to produce an error message. However, it is not |
| * always accurate. In the case where a single URI is mapped to more |
| * than one prefix in the XML view, the prefix of the first URI is provided. |
| * Therefore, to provide high quality error messages in cases where the |
| * tag elements themselves are checked, the prefix parameter should be |
| * ignored and the actual prefix of the element should be used instead. |
| * TagLibraryValidators should always use the uri to identify elements |
| * as beloning to the tag library, not the prefix. |
| * |
| * <p> |
| * A TagLibraryValidator instance |
| * may create auxiliary objects internally to perform |
| * the validation (e.g. an XSchema validator) and may reuse it for all |
| * the pages in a given translation run. |
| * |
| * <p> |
| * The JSP container is not guaranteed to serialize invocations of |
| * validate() method, and TagLibraryValidators should perform any |
| * synchronization they may require. |
| * |
| * <p> |
| * As of JSP 2.0, a JSP container must provide a jsp:id attribute to |
| * provide higher quality validation errors. |
| * The container will track the JSP pages |
| * as passed to the container, and will assign to each element |
| * a unique "id", which is passed as the value of the jsp:id |
| * attribute. Each XML element in the XML view available will |
| * be extended with this attribute. The TagLibraryValidator |
| * can then use the attribute in one or more ValidationMessage |
| * objects. The container then, in turn, can use these |
| * values to provide more precise information on the location |
| * of an error. |
| * |
| * <p> |
| * The actual prefix of the <code>id</code> attribute may or may not be |
| * <code>jsp</code> but it will always map to the namespace |
| * <code>http://java.sun.com/JSP/Page</code>. A TagLibraryValidator |
| * implementation must rely on the uri, not the prefix, of the <code>id</code> |
| * attribute. |
| */ |
| |
| abstract public class TagLibraryValidator { |
| |
| /** |
| * Sole constructor. (For invocation by subclass constructors, |
| * typically implicit.) |
| */ |
| public TagLibraryValidator() { |
| } |
| |
| /** |
| * Set the init data in the TLD for this validator. |
| * Parameter names are keys, and parameter values are the values. |
| * |
| * @param map A Map describing the init parameters |
| */ |
| public void setInitParameters(Map map) { |
| initParameters = map; |
| } |
| |
| |
| /** |
| * Get the init parameters data as an immutable Map. |
| * Parameter names are keys, and parameter values are the values. |
| * |
| * @return The init parameters as an immutable map. |
| */ |
| public Map getInitParameters() { |
| return initParameters; |
| } |
| |
| /** |
| * Validate a JSP page. |
| * This will get invoked once per unique tag library URI in the |
| * XML view. This method will return null if the page is valid; otherwise |
| * the method should return an array of ValidationMessage objects. |
| * An array of length zero is also interpreted as no errors. |
| * |
| * @param prefix the first prefix with which the tag library is |
| * associated, in the XML view. Note that some tags may use |
| * a different prefix if the namespace is redefined. |
| * @param uri the tag library's unique identifier |
| * @param page the JspData page object |
| * @return A null object, or zero length array if no errors, an array |
| * of ValidationMessages otherwise. |
| */ |
| public ValidationMessage[] validate(String prefix, String uri, |
| PageData page) |
| { |
| return null; |
| } |
| |
| /** |
| * Release any data kept by this instance for validation purposes. |
| */ |
| public void release() { |
| initParameters = null; |
| } |
| |
| // Private data |
| private Map initParameters; |
| |
| } |