auto taxonomy terms based on CCK field values

Here it is.

README.txt

Taxonomy terms by range

by Dave Rosenhauer, dave@dmrenterprises.com


This module allows you to gefine taxonomy categories and terms to be auto filled in based on numeric (or alpha?) ranges.

Setup:
1. Install the module.
2. Create a Category (administer->categories)
3. In the "Help Text:" field start the field with "AUTOFILL:" for example "AUTOFILL:Pricing Group" 
4. Add terms to the Category.
5. In the description field enter the range information in the following format:
  RANGE:<field_name>:<min_value>:<max_value> 
  <field_name> = the field name as it's refered to in the $node element.
  <min_value> = the lowest value to be in the range (uses field > min_value)
  <max_value> = the lowest value to be considered above the range (uses field < <max_value)
  for example 
    RANGE:price:0:50000
  This allows for adjacent ranges to use the same endpoints. you can setup several ranges (in seperate terms) as follows:
    RANGE:price:0:50000 >>> True if >= 0 and < 50000
    RANGE:price:50000:100000 >>> True if >= 50000 and < 100000
        
How it works:
Whenever a form is created the module checks if any Taxonomy categories are included. If one is included it then checks to see if the category has the "AUTOFILL:" in the help text.  If it finds it, it then removes the entry from the form.  Then during the form save (or update) it checks the values and assigns the proper term(s).

What if I need to change the ranges?  
In the Administration/Site Configuration menu select Taxonomy By Range.  If you check the "Force Update" box then submit it will scan for all nodes in the system that have AutoFill Taxonomy categories and update all of the terms (may take a while on large sites).  This is also helpful for adding new terms/categories.  Just Force an update and all current content is up to date.

taxbyrange.info

name = taxbyrange
dependencies  = taxonomy
description = "Set taxonomy terms by field value ranges"
package = "DMR Enterprises"

taxbyrange.module

<?php

/*
*******************************************************************************
** Update the terms based on the description field 
*******************************************************************************
*/
function taxbyrange_node_save($node) {  
  // Get the Taxonomy terms for this node
  $vocabularies = taxonomy_get_vocabularies($node->type);
  foreach ($vocabularies as $vocabulary) {
    $tree = taxonomy_get_tree($vocabulary->vid);
    foreach ($tree as $term) {

      if ($term->description) { // We have a description
        if (substr($term->description,0,6) == 'RANGE:') { //does the description start with 'RANGE'
          $params = explode(':',$term->description);  
          // $params[0] = 'RANGE' identifier
          // $params[1] = field name
          // $params[2] = min value (will use >=)
          // $params[3] = max value (will use <)
          $clearterm = false;
                    
          if ($node->$params[1]) {
            // The field in question has a value
            $fieldval = $node->$params[1];
             
            if (($fieldval >= $params[2]) && ($fieldval < $params[3])) {
              // Update the Taxonomy value
              // Check if it is already marked
              $query = "SELECT * FROM {term_node} WHERE nid = %d and tid = %d;"; 
              if (!db_result(db_query($query,$node->nid,$term->tid))) {          
                db_query("INSERT INTO {term_node} (nid,tid) VALUES (%d,%d)",$node->nid,$term->tid);
              }
            } else {
              // Have value and not in range so clear the term
              $clearterm = true;
            }
          } else {
            // Don't have value so clear term
            $clearterm = true;
           } 
          if ($clearterm == true) {
            // Delete the current term
            $query = "DELETE FROM {term_node} WHERE nid = %d and tid = %d;";  
            db_query($query,$node->nid,$term->tid);
          }
        }
      }
    }     
  }
}


/**
 * Implementation of hook_form_alter().
 * Generate a form for selecting terms to associate with a node.
 */
function taxbyrange_form_alter($form_id, &$form) {
  if (isset($form['type']) && $form['type']['#value'] .'_node_form' == $form_id) {
    $node = $form['#node'];

    // Check if any taxonomy fields are present
    if (is_array($form['taxonomy']) && !empty($form['taxonomy'])) {
      foreach ($form['taxonomy'] as $vid => $term) {
        if (substr($term['#description'],0,9) == 'AUTOFILL:') { //does the description start with 'AUTOFILL'
          // Remove the item as it will be auto filled
          unset($form['taxonomy'][$vid]);
        }  
      }
    }
  }
}


function taxbyrange_nodeapi($node, $op, $arg = 0) {
  switch ($op) {
    case 'insert':
      taxbyrange_node_save($node);
      break;
    case 'update':
      taxbyrange_node_save($node);
      break;
  }
}

function taxbyrange_admin_settings() {
  $form['queries'] = array('#type' => 'fieldset', '#title' => t('Update all Autolilled taxonomy fields'));
  
  $form['queries']['taxbyrange_update'] = array('#type' => 'checkbox',
    '#title' => t('Force Update'),
    '#default_value' => 0,
    '#description' => t("You should do this after changing the ranges for auto fill fields."),
  );
  
  return system_settings_form($form);
}

function taxbyrange_admin_settings_submit($form_id, $form_values) {
  if ($form_values['taxbyrange_update']){
    // get all of the autofill categories
    $vocabularies = taxonomy_get_vocabularies();
    $nodetypes = array();
  
    foreach ($vocabularies as $id => $vocabulary) {
      if (substr($vocabulary->help,0,9) == 'AUTOFILL:') { //does the description start with 'AUTOFILL' 
        // Add each node type that uses this vocab to the array (without dupes)
        foreach ($vocabulary->nodes as $node) {
          $nodetypes[$node] = $node;
        }  
      }  
    }
    
    // Now we have a list of the node types to process
    foreach ($nodetypes as $nodetype) {
      // Get the nodes for that type
      $query = "SELECT * FROM {node} WHERE type = '%s';"; 
              
      $result = db_query($query,$nodetype);
      while ($row = db_fetch_object($result)) {
        $tempnode = node_load($row->nid); 
        taxbyrange_node_save($tempnode);   
      }
    }
    
    form_set_error('form_token', t('Finished Updating all of the AutoFill taxonomy terms.'));
  }
}

/**
 * Implementation of hook_menu.
 */
function taxbyrange_menu($may_cache) {
  $items = array();
  if ($may_cache) {
   $items[] = array(
      'path' => 'admin/settings/taxbyrange',
      'title' => t('Taxonomy By Range'),
      'description' => t('Update Autofilled Taxonomy fields.'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('taxbyrange_admin_settings'),
      'access' => user_access('administer site configuration'),
      'type' => MENU_NORMAL_ITEM
    );
  }
  return $items;
}

?>

I actually didn't end up using your code.

Dave