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diff --git a/framework/src/ant/apache-ant-1.9.6/manual/Types/selectors-program.html b/framework/src/ant/apache-ant-1.9.6/manual/Types/selectors-program.html new file mode 100644 index 00000000..074a5426 --- /dev/null +++ b/framework/src/ant/apache-ant-1.9.6/manual/Types/selectors-program.html @@ -0,0 +1,244 @@ +<!-- + 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. +--> +<html> + <head> + <meta http-equiv="Content-Language" content="en-us"> + <link rel="stylesheet" type="text/css" href="../stylesheets/style.css"> +<title>Programming Selectors in Apache Ant</title> + </head> + + <body> + <h2>Programming your own Selectors</h2> + + <h3>Selector Programming API</h3> + + <p>Want to define your own selectors? It's easy!</p> + + <p>First, pick the type of selector that you want to define. There + are three types, and a recipe for each one follows. Chances are + you'll want to work with the first one, Custom Selectors.</p> + + <ol> + <li>Custom Selectors + + <p>This is the category that Apache Ant provides specifically for you to + define your own Selectors. Anywhere you want to use your selector + you use the <code><custom></code> element and specify + the class name of your selector within it. See the + <a href="selectors.html#customselect">Custom Selectors</a> + section of the Selector page for details. The + <code><custom></code> element can be used anywhere + the core selectors can be used. It can be contained within + <a href="selectors.html#selectcontainers">Selector Containers</a>, + for example.</p> + + <p>To create a new Custom Selector, you have to create a class that + implements + <code>org.apache.tools.ant.types.selectors.ExtendFileSelector</code>. + The easiest way to do that is through the convenience base class + <code>org.apache.tools.ant.types.selectors.BaseExtendSelector</code>, + which provides all of the methods for supporting + <code><param></code> tags. First, override the + <code>isSelected()</code> method, and optionally the + <code>verifySettings()</code> method. If your custom + selector requires parameters to be set, you can also override + the <code>setParameters()</code> method and interpret the + parameters that are passed in any way you like. Several of the + core selectors demonstrate how to do that because they can + also be used as custom selectors.</p> + + <li>Core Selectors + + <p>These are the selectors used by Ant itself. To implement one of + these, you will have to alter some of the classes contained within + Ant.</p> + + <ul> + <li><p>First, create a class that implements + <code>org.apache.tools.ant.types.selectors.FileSelector</code>. + You can either choose to implement all methods yourself from + scratch, or you can extend + <code>org.apache.tools.ant.types.selectors.BaseSelector</code> + instead, a convenience class that provides reasonable default + behaviour for many methods.</p> + + <p>There is only one method required. + <code>public boolean isSelected(File basedir, String filename, + File file)</code> + is the real purpose of the whole exercise. It returns true + or false depending on whether the given file should be + selected from the list or not.</p> + + <p>If you are using + <code>org.apache.tools.ant.types.selectors.BaseSelector</code> + there are also some predefined behaviours you can take advantage + of. Any time you encounter a problem when setting attributes or + adding tags, you can call setError(String errmsg) and the class + will know that there is a problem. Then, at the top of your + <code>isSelected()</code> method call <code>validate()</code> and + a BuildException will be thrown with the contents of your error + message. The <code>validate()</code> method also gives you a + last chance to check your settings for consistency because it + calls <code>verifySettings()</code>. Override this method and + call <code>setError()</code> within it if you detect any + problems in how your selector is set up.</p> + + <p>You may also want to override <code>toString()</code>.</p> + + <li><p>Put an <code>add</code> method for your selector in + <code>org.apache.tools.ant.types.selectors.SelectorContainer</code>. + This is an interface, so you will also have to add an implementation + for the method in the classes which implement it, namely + <code>org.apache.tools.ant.types.AbstractFileSet</code>, + <code>org.apache.tools.ant.taskdefs.MatchingTask</code> and + <code>org.apache.tools.ant.types.selectors.BaseSelectorContainer</code>. + Once it is in there, it will be available everywhere that core + selectors are appropriate.</p> + </ul> + + <li>Selector Containers + <p>Got an idea for a new Selector Container? Creating a new one is + no problem:</p> + <ul> + <li><p>Create a new class that implements + <code>org.apache.tools.ant.types.selectors.SelectorContainer</code>. + This will ensure that your new + Container can access any new selectors that come along. Again, there + is a convenience class available for you called + <code>org.apache.tools.ant.types.selectors.BaseSelectorContainer</code>. + </p> + <li><p>Implement the + <code>public boolean isSelected(String filename, File file)</code> + method to do the right thing. Chances are you'll want to iterate + over the selectors under you, so use + <code>selectorElements()</code> to get an iterator that will do + that.</p> + <li><p>Again, put an <code>add</code> method for your container in + <code>org.apache.tools.ant.types.selectors.SelectorContainer</code> + and its implementations + <code>org.apache.tools.ant.types.AbstractFileSet</code> and + <code>org.apache.tools.ant.types.selectors.BaseSelectorContainer</code>. + </p> + </ul> + </ol> + + <h3>Testing Selectors</h3> + + <p>For a robust component (and selectors are (Project)Components) tests are + necessary. For testing Tasks we use JUnit TestCases - more specific + <tt>org.apache.tools.ant.BuildFileRule extends org.junit.rules.ExternalResource</tt>. + Some of its features like configure the (test) project by reading its buildfile and + execute targets we need for selector tests also. Therefore we use that BuildFileRule. + But testing selectors requires some more work: having a set of files, instantiate + and configure the selector, check the selection work and more. Because we usually + extend <tt>BaseExtendSelector</tt> its features have to be tested also (e.g. setError()). + </p> + + <p>That's why we have a test rule for doing our selector tests: + <tt>org.apache.tools.ant.types.selectors.BaseSelectorRule</tt>.</p> + + <p>This class extends ExternalResource and therefore can included in the set of Ant's + unit tests. It holds an instance of preconfigured BuildFileRule. Configuration + is done by parsing the src/etc/testcases/types/selectors.xml. BaseSelectorRule + then gives us helper methods for handling multiple selections. </p> + + <p>Because the term "testcase" or "testenvironment" are so often used, this + special testenvironment got a new name: <i>bed</i>. The setup and cleanup of + the bed is all handled by the BaseSelectorRule so any test only has to handle + the actual test scenarios</p> + + <p>A usual test scenario is:</p> + <ol> + <li>instantiate the selector</li> + <li>configure the selector</li> + <li>let the selector do some work</li> + <li>verify the work</li> + </ol> + + + + <p>An example test would be:<pre> +package org.apache.tools.ant.types.selectors; + +public class MySelectorTest { + + @Rule + public final BaseSelectorRule selectorRule = new BaseSelectorRule(); + + @Test + public void testCase1() { + + + // Configure the selector + MySelector s = new MySelector(); + s.addParam("key1", "value1"); + s.addParam("key2", "value2"); + s.setXX(true); + s.setYY("a value"); + + // do the tests + assertEquals("FTTTTTTTT", selectorRule.selectionString(s)); + } +} + </pre> + As an example of an error JUnit could log<pre> + [junit] FAILED + [junit] Error for files: <font color=blue>.;copy.filterset.filtered;tar/gz/asf-logo.gif.tar.gz</font> + [junit] expected:<<font color=blue>FTTTFTTTF...</font>> but was:<TTTTTTTTT...> + [junit] junit.framework.ComparisonFailure: Error for files: .;copy.filterset.filtered;tar/gz/asf-logo.gif.tar.gz + [junit] expected:<FTTTFTTTF...> but was:<TTTTTTTTT...> + [junit] at junit.framework.Assert.assertEquals(Assert.java:81) + [junit] at org.apache.tools.ant.types.selectors.BaseSelectorTest.performTest(BaseSelectorTest.java:194) + </pre></p> + + <p>Described above the test class should provide a <tt>getInstance()</tt> + method. But that isn't used here. The used <tt>getSelector()</tt> method is + implemented in the base class and gives an instance of an Ant Project to + the selector. This is usually done inside normal build file runs, but not + inside this special environment, so this method gives the selector the + ability to use its own Project object (<tt>getProject()</tt>), for example + for logging.</p> + + + <h3>Logging</h3> + + <p>During development and maybe later you sometimes need the output of information. + Therefore Logging is needed. Because the selector extends BaseExtendSelector or directly + BaseSelector it is an Ant <tt>DataType</tt> and therefore a <tt>ProjectComponent</tt>. <br> + That means that you have access to the project object and its logging capability. + <tt>ProjectComponent</tt> itself provides <i>log</i> methods which will do the + access to the project instance. Logging is therefore done simply with: + <pre> + log( "message" ); + </pre> + or + <pre> + log( "message" , loglevel ); + </pre> + where the <tt>loglevel</tt> is one of the values <ul> + <li> org.apache.tools.ant.Project.MSG_ERR </li> + <li> org.apache.tools.ant.Project.MSG_WARN </li> + <li> org.apache.tools.ant.Project.MSG_INFO (= default) </li> + <li> org.apache.tools.ant.Project.MSG_VERBOSE </li> + <li> org.apache.tools.ant.Project.MSG_DEBUG </li> + </ul> + </p> + + + </body> + +</html> |