InputfieldDecimal.module

<?php

/**
 * ProcessWire Decimal Inputfield
 *
 * Part of FieldtypeDecimal. See
 * https://processwire.com/talk/topic/7542-development-fieldtypefloat-fieldtypedecimal/
 *
 * ProcessWire 2.x 
 * 
 */
 
class InputfieldDecimal extends InputfieldInteger
{
  public static function getModuleInfo()
  {
    return array(
      'title'     => __('Decimal', __FILE__),
      'summary'   => __('Floating point number with exact precision', __FILE__),
      'version'   => 100,
      'author'    => 'Sebastian Forsman',
      'href'      => 'https://github.com/sforsman/InputfieldDecimal',
      'requires'  => 'FieldtypeDecimal',
    );
  }

  public function __construct()
  {
    $this->set('digits', 12); 
    $this->set('precision', 2); 
    parent::__construct();
  }

  public function init()
  {
    parent::init();
    $this->attr('step', 'any'); // HTML5 attr required to support decimals with 'number' types
  }
  
  public function getConfigInputfields()
  {
    $inputfields = parent::getConfigInputfields();
    
    // TODO: Switch min/max vals so they use this class

    return $inputfields; 
  }


  protected function sanitizeValue($value)
  {
    // We accept the decimal separator as humans naturally write them
    $value = str_replace(",",".",$value);
    
    // According to wire/core/Fieldtype.php:
    // "If it can't be sanitized, it should be blanked."
    // is_numeric() lets weird stuff through, but that's fine for now
    if(!is_numeric($value))
      $value = "";
    
    return $value; 
  }

  /**
   * Returns true if number is in valid range, false if not
   *
   * Overriding the function from InputfieldInteger to ensure float types (rather than int types) are used
   *
   */
  protected function isInRange($value)
  {
    $inRange = true;
    $min = $this->attr('min');
    $max = $this->attr('max');
    if(strlen("$value")) {
      if(strlen("$min") && ($this->compareNumbers($value, $min) == -1)) {
        $inRange = false;
      }
      if(strlen("$max") && ($this->compareNumbers($value, $max) == 1)) {
        $inRange = false;
      }
    }
    return $inRange;
  }
  
  /**
   * Returns a comparison integer based on the best possible method
   *
   * Falls back in to floating-point comparison if no precision library is available
   *
   */
  protected function compareNumbers($a,$b)
  {
    if(function_exists("gmp_cmp"))
    {
      return gmp_cmp($a,$b);
    }
    elseif(function_exists("bccomp"))
    {
      return bccomp($a,$b,$this->precision);
    }
    else
    {
      $a = round($a, $this->precision);
      $b = round($b, $this->precision);
      
      if($a == $b)
        return 0;
      elseif($a < $b)
        return -1;
      else
        return 1;
    }
  }
}