Attachment 37867 Details for Bug 65124 – Sample plug-in for <c:set .../>

Sample plug-in for <c:set .../>

CoreSetPlugin.java (text/plain), 2.59 KB, created by Mark Thomas on 2021-05-18 16:23:12 UTC

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Creator: Mark Thomas

Created: 2021-05-18 16:23:12 UTC

Size: 2.59 KB

patch

obsolete

>/*
>* 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 jsp2.examples.plugins;
>
>import org.apache.jasper.compiler.tagplugin.TagPlugin;
>import org.apache.jasper.compiler.tagplugin.TagPluginContext;
>
>/**
> * Tag plug-in implementation intended to demonstrate a simple optimisation case
> * based on the requirements described in
> * <a href="https://bz.apache.org/bugzilla/show_bug.cgi?id=65124">bug 65124</a>.
> */
>public class CoreSetPlugin implements TagPlugin {
>
>    @Override
>    public void doTag(TagPluginContext ctxt) {
>        if (!ctxt.isAttributeSpecified("value")) {
>            // Value is defined in tag body.
>            // Don't optimise
>            ctxt.dontUseTagPlugin();
>            return;
>        }
>
>        if (ctxt.isAttributeSpecified("target") || ctxt.isAttributeSpecified("property")) {
>            // Attempting to set a property on an object
>            // Don't optimise
>            ctxt.dontUseTagPlugin();
>            return;
>        }
>
>        if (!ctxt.isAttributeSpecified("var")) {
>            // No target variable defined
>            // Don't optimise
>            ctxt.dontUseTagPlugin();
>            return;
>        }
>
>        if (ctxt.isAttributeSpecified("scope")) {
>            // TODO - we can easily parse this rather than only support the default.
>            ctxt.dontUseTagPlugin();
>            return;
>        }
>
>        ctxt.generateJavaSource("pageContext.setAttribute(");
>        if (ctxt.isConstantAttribute("var")) {
>            ctxt.generateJavaSource("\"" + ctxt.getConstantAttribute("var") + "\"");
>        } else {
>            ctxt.generateAttribute("var");
>        }
>        ctxt.generateJavaSource(", ");
>        if (ctxt.isConstantAttribute("value")) {
>            ctxt.generateJavaSource("\"" + ctxt.getConstantAttribute("value") + "\"");
>        } else {
>            ctxt.generateAttribute("value");
>        }
>        ctxt.generateJavaSource(", 1);");
>    }
>}

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Attachments on bug 65124: 37726 | 37867