A first attempt at writing a Phing Task

RandomStringTask.php

<?php

require_once "phing/Task.php";

class RandomStringTask extends Task {

    /**
     * The length of the random string
     */
    private $length = 32;

    /** 
     * The ASCII range start character number for the characters 
     * used in the string
     */
    private $ascii_start = 33;

    /** 
     * The ASCII range end character number for the characters 
     * used in the string
     */
    private $ascii_stop = 126;

    /**
     * Set the return value to this property
     */
    private $propertyName = null;

    /** 
     * Exclude these comma seperated ascii numbers by default
     * by default exclude: double quote, single quote and apastroph
     */
    private $exclude = '34, 39, 96';


    /**
     * The setter for the attribute "length"
     */
    public function setLength($length) {
        $this->length = (int) $length; 
    }

    /**
     * The setter for the attribute "ascii_start"
     */
    public function setAscii_Start($ascii_start) {
        $this->ascii_start = (int) $ascii_start; 
    }

    /**
     * The setter for the attribute "ascii_stop"
     */
    public function setAscii_Stop($ascii_stop) {
        $this->ascii_stop = (int) $ascii_stop; 
    }


    /**
     * The getter for the attribute "ascii_start"
     */
    public function getAscii_Start($ascii_start) {
        return $this->ascii_start; 
    }

    /**
     * The getter for the attribute "ascii_stop"
     */
    public function getAscii_Stop($ascii_stop) {
        return $this->ascii_stop; 
    }



    /**
     * The setter for the attribute "value"
     */
    public function setPropertyName($propertyName) {
        $this->propertyName = $propertyName; 
    }

    /**
     * The getter for the attribute "value"
     */
    public function getPropertyName() {
        return $this->propertyName;  
    }

    
    /**
     * The init method: Do init steps.
     */
    public function init() {
      // nothing to do here
    }

    /**
     * The main entry point method.
     */
    public function main() {
      if ( $this->propertyName === null) {
        throw new BuildException("You must specify a value for propertyName attribute.");
      }

      // prevent non printable characters from selecting
      if( $this->ascii_start < (int) 33) {
        throw new BuildException("The ascii_start property value needs a value bigger than 33");
      }  
        
      if( $this->ascii_stop > (int) 126) {
        throw new BuildException("The ascii_stop property value needs a value smaller than 126");
      }  

      $this->project->setUserProperty( $this->getPropertyName(), $this->randomString()); 
    }

    /**
     * Retrieves and processes the ascii numbers which should not be used 
     */
    private function getExcludedAsciiNumbers() {
      $excluded = explode(',', $this->exclude);
      if( is_array($excluded) ) {
        array_walk( $excluded, function(&$value, $key) { $value = trim($value); $value = (int)$value; } );
      }      
      return $excluded;
    }


    /** 
     * Generate a string of a given length with random characters in the ASCII
     * range given See for instance http://www.asciitable.com/
     */ 
    private function randomString() {
      $str = '';
      $excluded = $this->getExcludedAsciiNumbers();
      
      for( $i = 0; $i <= $this->length; $i++) {
        $ascii_nr = $this->randomNumber(); 
        $str .= chr( $ascii_nr );
      }
      return $str;
    }

    
    /** 
     * Generates a random number between the 
     * $ascii_start and $ascii_top values and prevents using
     * an excluded number
     */ 
    function randomNumber() {
      $excluded = $this->getExcludedAsciiNumbers();
      $ascii_nr = mt_rand( $this->ascii_start, $this->ascii_stop );
      if( in_array($ascii_nr, $excluded) ) {
        $this->randomNumber(); 
      } else {
        return $ascii_nr;
      }
    }

}
?>

test-random-string.xlm

<?xml version="1.0" ?>

<project name="test-random-string-task" basedir="." default="test.randomstring">
  <taskdef name="randomstring" classname="RandomStringTask" />

    <target name="test.randomstring">
      <randomstring length="32" propertyName="test.rndstr" ascii_start="33" ascii_stop="100" />
      <echo message="The Random String: ${test.rndstr}" />
    </target>
</project>