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| <html> |
| |
| <head> |
| <meta http-equiv="Content-Language" content="en-us"> |
| <link rel="stylesheet" type="text/css" href="../stylesheets/style.css"> |
| <title>Scriptdef Task</title> |
| </head> |
| |
| <body> |
| |
| <h2><a name="script">Scriptdef</a></h2> |
| <h3>Description</h3> |
| <p>Scriptdef can be used to define an Apache Ant task using a scripting language. Ant |
| scripting languages supported by |
| <a href="http://jakarta.apache.org/bsf" target="_top">Apache BSF</a> |
| or |
| <a href="https://scripting.dev.java.net">JSR 223</a> |
| may be |
| used to define the script. Scriptdef provides a mechanism to encapsulate |
| control logic from a build within an Ant task minimizing the need for |
| providing control style tasks in Ant itself. Complex logic can be made |
| available while retaining the simple structure of an Ant build file. Scriptdef |
| is also useful for prototyping new custom tasks. Certainly as the complexity |
| of the script increases it would be better to migrate the task definition |
| into a Java based custom task. |
| </p> |
| |
| <p><b>Note:</b> This task depends on external libraries not included in the |
| Ant distribution. See |
| <a href="../install.html#librarydependencies">Library Dependencies</a> |
| for more information.</p> |
| |
| |
| |
| <p>The attributes and nested elements supported by the task may be defined |
| using <code><attribute></code> and <code><element></code> nested elements. These are |
| available to the script that implements the task as two collection style |
| script variables <code>attributes</code> and <code>elements</code>. The |
| elements in the <code>attributes</code> collection may be accessed by the |
| attribute name. The <code>elements</code> collection is accessed by the nested |
| element name. This will return a list of all instances of the nested element. |
| The instances in this list may be accessed by an integer index. |
| </p> |
| |
| <p><b>Note:</b> Ant will turn all attribute and element names into all |
| lowercase names, so even if you use name="SomeAttribute", you'll have |
| to use "someattribute" to retrieve the attribute's value from the |
| <code>attributes</code> collection.</p> |
| |
| <p>The name "self" (<i>since Ant 1.6.3</i>) is a pre-defined reference to the |
| script def task instance. |
| It can be used for logging, or for integration with the rest of |
| ant. the <code>self.text attribute</code> contains |
| any nested text passed to the script</p> |
| |
| <p>If an attribute or element is not passed in, |
| then <code>attributes.get()</code> or <code>elements.get()</code> will |
| return null. It is up to the script to perform any checks and validation. |
| <code>self.fail(String message)</code>can be used to raise a |
| <code>BuildException</code>. |
| </p> |
| |
| |
| <p>The name "project" is a pre-defined reference to the Ant Project. For |
| more information on writing scripts, please refer to the |
| <a href="script.html"><code><script></code></a> task |
| </p> |
| |
| |
| <h3>Parameters</h3> |
| <table border="1" cellpadding="2" cellspacing="0"> |
| <tr> |
| <td valign="top"><b>Attribute</b></td> |
| <td valign="top"><b>Description</b></td> |
| <td align="center" valign="top"><b>Required</b></td> |
| </tr> |
| <tr> |
| <td valign="top">name</td> |
| <td valign="top">the name of the task to be created using the script</td> |
| <td valign="top" align="center">Yes</td> |
| </tr> |
| <tr> |
| <td valign="top">language</td> |
| <td valign="top">The programming language the script is written in. |
| Must be a supported Apache BSF or JSR 223 language</td> |
| <td valign="top" align="center">Yes</td> |
| </tr> |
| <tr> |
| <td valign="top">manager</td> |
| <td valign="top"> |
| The script engine manager to use. |
| See the <a href="../Tasks/script.html">script</a> task |
| for using this attribute. |
| </td> |
| <td valign="top" align="center">No - default is "auto"</td> |
| </tr> |
| <tr> |
| <td valign="top">src</td> |
| <td valign="top">The location of the script as a file, if not inline</td> |
| <td valign="top" align="center">No</td> |
| </tr> |
| <tr> |
| <td valign="top">uri</td> |
| <td valign="top"> |
| The XML namespace uri that this definition should live in. |
| </td> |
| <td valign="top" align="center">No</td> |
| </tr> |
| <tr> |
| <td valign="top">classpath</td> |
| <td valign="top"> |
| The classpath to pass into the script. |
| </td> |
| <td align="center" valign="top">No</td> |
| </tr> |
| <tr> |
| <td valign="top">classpathref</td> |
| <td valign="top">The classpath to use, given as a |
| <a href="../using.html#references">reference</a> to a path defined elsewhere. |
| <td align="center" valign="top">No</td> |
| </tr> |
| <tr> |
| <td valign="top">loaderRef</td> |
| <td valign="top">the name of the loader that is |
| used to load the script, constructed from the specified |
| classpath. This allows multiple script definitions |
| to reuse the same class loader. |
| </td> |
| <td align="center" valign="top">No</td> |
| </tr> |
| </table> |
| |
| <h3>Nested elements</h3> |
| <h4>attribute</h4> |
| <table border="1" cellpadding="2" cellspacing="0"> |
| <tr> |
| <td valign="top"><b>Attribute</b></td> |
| <td valign="top"><b>Description</b></td> |
| <td align="center" valign="top"><b>Required</b></td> |
| </tr> |
| <tr> |
| <td valign="top">name</td> |
| <td valign="top">the name of the attribute</td> |
| <td valign="top" align="center">Yes</td> |
| </tr> |
| </table> |
| |
| <h4>element</h4> |
| <table border="1" cellpadding="2" cellspacing="0"> |
| <tr> |
| <td valign="top"><b>Attribute</b></td> |
| <td valign="top"><b>Description</b></td> |
| <td align="center" valign="top"><b>Required</b></td> |
| </tr> |
| <tr> |
| <td valign="top">name</td> |
| <td valign="top">the name of the nested element to be supported by the |
| task defined by the script</td> |
| <td valign="top" align="center">Yes</td> |
| </tr> |
| <tr> |
| <td valign="top">classname</td> |
| <td valign="top">the classname of the class to be used for the nested element. |
| This specifies the class directly and is an alternative to specifying |
| the Ant type name.</td> |
| <td valign="top" align="center">No</td> |
| </tr> |
| <tr> |
| <td valign="top">type</td> |
| <td valign="top">This is the name of an Ant task or type which is to |
| be used when this element is to be created. This is an alternative |
| to specifying the class name directly. If the type is in a namespace, |
| the URI and a : must be prefixed to the type. For example |
| <code>type="antlib:example.org:newtype"</code></td> |
| <td valign="top" align="center">No</td> |
| </tr> |
| <tr> |
| <td valign="top">any resource or resource collection</td> |
| <td valign="top">Since Ant1.7.1, this task can load scripts |
| from any resource supplied as a nested element. when </td> |
| <td valign="top" align="center">No</td> |
| </tr> |
| |
| </table> |
| |
| <h4>classpath</h4> |
| <p> |
| See the <a href="../Tasks/script.html">script</a> task |
| for using this nested element. |
| </p> |
| |
| |
| <h3>Examples</h3> |
| |
| <p> |
| The following definition creates a task which supports an attribute called |
| attr and two nested elements, one being a fileset and the other a path. When |
| executed, the resulting task logs the value of the attribute and the basedir |
| of the first fileset. |
| </p> |
| |
| <pre> |
| <scriptdef name="scripttest" language="javascript"> |
| <attribute name="attr1"/> |
| <element name="fileset" type="fileset"/> |
| <element name="path" type="path"/> |
| <![CDATA[ |
| |
| self.log("Hello from script"); |
| self.log("Attribute attr1 = " + attributes.get("attr1")); |
| self.log("First fileset basedir = " |
| + elements.get("fileset").get(0).getDir(project)); |
| |
| ]]> |
| </scriptdef> |
| |
| <scripttest attr1="test"> |
| <path> |
| <pathelement location="src"/> |
| </path> |
| <fileset dir="src"/> |
| <fileset dir="main"/> |
| </scripttest> |
| </pre> |
| |
| <p> |
| The following variation on the above script lists the number of fileset elements |
| and iterates through them |
| </p> |
| <pre> |
| <scriptdef name="scripttest2" language="javascript"> |
| <element name="fileset" type="fileset"/> |
| <![CDATA[ |
| filesets = elements.get("fileset"); |
| self.log("Number of filesets = " + filesets.size()); |
| for (i = 0; i < filesets.size(); ++i) { |
| self.log("fileset " + i + " basedir = " |
| + filesets.get(i).getDir(project)); |
| } |
| ]]> |
| </scriptdef> |
| |
| <scripttest2> |
| <fileset dir="src"/> |
| <fileset dir="main"/> |
| </scripttest2> |
| </pre> |
| |
| <p> |
| When a script has a syntax error, the scriptdef name will be listed in the |
| error. For example in the above script, removing the closing curly bracket |
| would result in this error |
| </p> |
| |
| <p><code>build.xml:15: SyntaxError: missing } in compound |
| statement (scriptdef <code><scripttest2></code>; line 10)</code></p> |
| |
| <p> |
| Script errors are only detected when a script task is actually executed. |
| </p> |
| <p> |
| The next example does uses nested text in Jython. It also declares |
| the script in a new xml namespace, which must be used to refer to |
| the task. Declaring scripts in a new namespace guarantees that Ant will |
| not create a task of the same (namespace,localname) name pair. |
| </p> |
| |
| <pre> |
| <target name="echo-task-jython"> |
| <scriptdef language="jython" |
| name="echo" |
| uri="http://example.org/script"> |
| <![CDATA[ |
| self.log("text: " +self.text) |
| ]]> |
| </scriptdef> |
| </target> |
| |
| <target name="testEcho" depends="echo-task-jython" |
| xmlns:s="http://example.org/script"> |
| <s:echo>nested text</s:echo> |
| </target> |
| </pre> |
| |
| The next example shows the use of <classpath> and |
| "loaderref" to get access to the beanshell jar. |
| <pre> |
| <scriptdef name="b1" language="beanshell" |
| loaderref="beanshell-ref"> |
| <attribute name="a"/> |
| <classpath |
| path="${user.home}/scripting/beanshell/bsh-1.3b1.jar"/> |
| self.log("attribute a is " + attributes.get("a")); |
| </scriptdef> |
| |
| <scriptdef name="b2" language="beanshell" |
| loaderref="beanshell-ref"> |
| <attribute name="a2"/> |
| self.log("attribute a2 is " + attributes.get("a2")); |
| </scriptdef> |
| |
| <b1 a="this is an 'a'"/> |
| <b2 a2="this is an 'a2' for b2"/> |
| </pre> |
| <h3>Testing Scripts</h3> |
| |
| <p> |
| The easiest way to test scripts is to use the |
| <a href="http://ant.apache.org/antlibs/antunit/">AntUnit</a> ant library. |
| This will run all targets in a script that begin with "test" (and their dependencies). </p> |
| |
| |
| |
| |
| </body> |
| </html> |
