Create a revision archive for field values

ATK Howto: Create a revision archive for field values Complexity: Expert Author: Olav B. Lygre <soppel at lygre dot no>

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Describes how to create a revision system so every change in selected fields in a node can be tracked.

First create a table:

 CREATE TABLE IF NOT EXISTS `revision` (
 `rev_table` varchar( 50 ) NOT NULL ,
 `rev_field` varchar( 50 ) NOT NULL ,
 `rev_atkprimkey` varchar( 200 ) NOT NULL ,
 `rev_datetime` datetime NOT NULL ,
 `rev_username` varchar( 25 ) NOT NULL ,
 `rev_value` text,
 PRIMARY KEY ( `rev_table` , `rev_field` , `rev_datetime` , `rev_username` , `rev_atkprimkey` ))

Then use this baseclass instead of your usual atkNode. Add fields from your node to $this->m_revision_fields(array("field1","field")); Then every fieldchange in these fields will be saved to the database.

 class watkNode extends atkNode {   
 var $m_revision_fields=array();  //Add fields from your node here to track changes
 function watkNode($type, $flags="")
   { 
   $this->atkNode($type, $flags);  
   if (count($this->m_revision_fields)>0)
     $this->addFlag(NF_TRACK_CHANGES);
   }
 function postUpdate($record)
   {
   if (count($this->m_revision_fields)>0)
     $this->checkrevision($record);  
   parent::postUpdate($record);
   return true;       
   }
 function postAdd($record)
   {
   if (count($this->m_revision_fields)>0)
     $this->checkrevision($record);  
   parent::postAdd($record);
   return true;       
   }
 function  checkrevision($record)
   {
   $save_revision_fields=array();
   foreach($this->m_revision_fields as $revision_field)
     if ($record[$revision_field]<>$record['atkorgrec'][$revision_field])
       $save_revision_fields[$revision_field]=$record[$revision_field];
   if (count($save_revision_fields)>0)
     $this->updaterevision($record['atkprimkey'],$save_revision_fields);
   $return;
   }
 function updaterevision($rev_atkprimkey,$save_revision_fields)
   {
   $revnode=&atkGetNode("revision.revision");
   global $g_user;
   $update_datetime=array('year'=>date('Y'),
        'month'=>date('m'),
        'day'=>date('d'),
        'hours'=>date('H'),
        'minutes'=>date('i'),
        'seconds'=>date('s')); 
        $rev_atkprimkey=str_replace("'","",$rev_atkprimkey);  //due to problems with ' in urls
   foreach($save_revision_fields as $field=>$value) {
     $rec['rev_atkprimkey']=$rev_atkprimkey;
     $rec['rev_table']=$this->m_table;
     $rec['rev_field']=$field;
     $rec['rev_username']=$g_user["full_name"];
     $rec['rev_datetime']= $update_datetime;
     $rec['rev_value']=$value;
     $revnode->addDb($rec); 
     unset($rec);
     }
   }
 }

The revision node:

 useattrib("atkattribute"); 
 useattrib("atkdatetimeattribute"); 
 useattrib("atktextattribute"); 
 class revision extends atkNode { 
   function revision()
   { $this->atkNode("revision",NF_ADD_LINK);
     $this->add(new atkAttribute("rev_atkprimkey", AF_SEARCHABLE|AF_PRIMARY));
     $this->add(new atkAttribute("rev_table", AF_SEARCHABLE|AF_PRIMARY));
     $this->add(new atkAttribute("rev_field", AF_SEARCHABLE|AF_PRIMARY));
     $this->add(new atkDateTimeAttribute("rev_datetime", AF_SEARCHABLE|AF_PRIMARY));
     $this->add(new atkAttribute("rev_username", AF_SEARCHABLE));
     $this->add(new atkTextAttribute("rev_value", AF_SEARCHABLE));          
      $this->setOrder("rev_table,rev_field,rev_datetime");
     $this->setTable("revision");
   }
 }

What's missing here is a generic way of showing the different revisions. An example of how this may look in the outlook theme is showed below. This requires editing the edit & view handler, and the two templates.