Default or Calculated Dependee Attributes

ATK Howto: Default or Calculated Dependee Attributes Complexity: Easy Author: [Wayne H] wayne@hulls.net.nz

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Example code of how to create dependee attributes which can be defaulted to a calculated value and edited or always calauated and read only

class.testdeps.inc

<?php
  /**
  *
  * testdeps - test dependees
  *
  * attribute "number" can have any number entered
  * attributes "depnoedit" and depnoro" are BOT dependeess of attribute "number"
  * attribute "depnoedit" IF blank is set to a default value of half of attribute "number"
  *	attribute "depnoedit" is EDITABLE
  * attribute "depnoro" is always half of attribute "number" and is READ ONLY
  *
  * TABLE create SQL
  * CREATE TABLE `testdeps` (
  *	`pktestdep` INT(10) UNSIGNED NOT NULL DEFAULT '0',
  *	`number` INT(10) UNSIGNED NULL DEFAULT NULL,
  *	`depnoedit` INT(10) UNSIGNED NULL DEFAULT NULL,
  *	`depnoro` INT(10) UNSIGNED NULL DEFAULT NULL,
  *	PRIMARY KEY (`pktestdep`)
  *	)
  * COLLATE=utf8_general_ci
  * ENGINE=MyISAM
  * ROW_FORMAT=DYNAMIC
  * AVG_ROW_LENGTH=0
  */
  
  useattrib("atknumberattribute");

  class testdeps extends atkNode
  {
    function testdeps()
    {
      $this->atkNode("testdeps", NF_ADD_LINK|NF_ADDAFTERADD);
	  
	  // Primary key
      $this->add(new atkAttribute("pktestdep", AF_AUTOINCREMENT|AF_PRIMARY|AF_HIDE));
      
	  // value for "number" can be entered
	  $attr_number = &$this->add(new atkNumberAttribute("number"));
	  
	  // Fields are dependent on "number"
      $attr_number->addDependee("depnoedit");
      $attr_number->addDependee("depnoro");

	  
	  // If blank is set to a default value. Is always editable 
      $attr_depnoedit = &$this->add(new atkNumberAttribute("depnoedit"));

	  // Is always calculated from "number" and is always READ ONLY
      $attr_depnoro = &$this->add(new atkNumberAttribute("depnoro",AF_READONLY));
	  	  
	  $this->setOrder("pktestdep");
      $this->setIndex("pktestdep");	  
	  $this->setTable("testdeps");
	  
    } // function testdeps
	

   // Override normal attribute edit
   function depnoedit_edit($record, $mode)
   {
      // Set default value IF attribute is empty
	  if ($record["depnoedit"]=='') {
	    $record["depnoedit"] = $record["number"] * 0.5;     
	  }
	    // return editable value
	    $attr = &$this->getAttribute("depnoedit");
        return $attr->edit($record, $mode); 
	} //function    

   // Overrode normal attribute display 	
   function depnoro_display($record, $mode)
   {
      // Calculate value of attribute "depnoro"
	  $record["depnoro"] = $record["number"] * 0.5;     
	  
	  // return displayable value
	  $attr = &$this->getAttribute("depnoro");
      return $attr->display($record, $mode); 
   }
   
  } //Class
?>