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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>The Command Line Processor Plugin: ArgumentProcessor</title> |
| </head> |
| |
| <body> |
| <h1>The Command Line Processor Plugin: ArgumentProcessor</h1> |
| |
| <h2><a name="definition">What is an ArgumentProcessor?</a></h2> |
| |
| <p> |
| An <code>ArgumentProcessor</code> is a parser of command line argument which is |
| then call before and after the build file is being parsed. Third party |
| libraries may then be able to have custom argument line argument which modify |
| Ant behaviour. |
| </p> |
| |
| <p> |
| An <code>ArgumentProcessor</code> is called each time Ant parse an unknown |
| argument, an <code>ArgumentProcessor</code> doesn't take precedence over Ant to |
| parse already suported options. It is then recommended to third party |
| <code>ArgumentProcessor</code> implementation to chose specific 'enough' |
| argument name, avoiding for instance one letter arguments. |
| </p> |
| |
| <p> |
| It is also called at the different phases so different behaviour can be |
| implemented. It is called just after every arguments are parsed, just |
| before the project is being configured (the build file being parsed), |
| and just after. Some of the methods to be implemented return a boolean: |
| if <code>true</code> is returned, Ant will terminate immediately, without |
| error. |
| </p> |
| |
| <p> |
| Being called during all these phases, an <code>ArgumentProcessor</code> |
| can just print some specific system properties and quit (like |
| <code>-diagnose</code>), or print some specific properties of a project after |
| being parsed and quit (like <code>-projectHelp</code>), or just set some |
| custom properties on the project and let it run. |
| </p> |
| |
| <h2><a name="repository">How to register it's own ArgumentProcessor</a></h2> |
| |
| <p>First, the <code>ArgumentProcessor</code> must be an implementation of |
| <code>org.apache.tools.ant.ArgumentProcessor</code>. |
| </p> |
| |
| <p>Then to decare it: create a file |
| <code>META-INF/services/org.apache.tools.ant.ArgumentProcessor</code> which |
| contains only one line the fully qualified name of the class of the |
| implementation. This file together with the implementation class need then to |
| be found in Ant's classpath. |
| </p> |
| </body> |
| </html> |
| |
