Command options

The CTL get-opts task provides a command line option parsing facility. This task accepts one or more <opt> tags, each defining a new option. Options can be defined to take an argument or work like a boolean flag. Options that take arguments can also have a default value assigned if the option is not provided by the user. The values of these options can be referenced from within your implementations as a property value.

The example below describes a command that takes an option called -message. The value of the -message argument is used by the echo task:

    
      <command name="hello" description="say hello with Ant." 
               command-type="AntCommand" is-static="true">
        <implementation>
	  <echo message="${opts.message}"/>
        </implementation>
        <!--
	  ** Define an option called "-message".
	  ** The command line will be parsed and set the 
	  ** value to the property named opts.message
	  -->
        <opts>
          <opt parameter="message" description="option name" required="false"
	       property="opts.message" type="string" default="hello"/>
        </opts>
      </command>
      

Running the command without argument will return the default string "hello":

	ctl -m poly -c hello
	hello
      

Now run the command with an argument:

	ctl -m poly -c hello -- -message hola
	hola
      

Attributes and options

The ProjectBuilder's build-type command will generate a file called type.properties that is automatically read in before the tasks within the implementation tags.

    
    <!-- 
      ** define an attribute named "message" to use as a default.
      -->
     <attributes>
       <attribute-default name="message" value="guten tag"/>
     </attributes>
     <commands>
      <command name="hello" description="say hello with Ant." 
               command-type="AntCommand" is-static="true">
        <implementation>
	  <echo message="${opts.message}"/>
        </implementation>
        <opts>
	  <!-- 
	    ** the "defaultproperty" (if set) takes precedence 
	       over the literal value, "hello"
	    -->
          <opt parameter="message" description="option name" required="false"
	       property="opts.message" type="string" default="hello" 
	       defaultproperty="entity.attribute.message"/>
        </opts>
      </command>
    </commands>
      

      ctl -m poly -c hello
      guten tag
      

Of course, the command line has overall precedence:

      ctl -m poly -c hello -- -message hi
      hi