<?php
/**
 * @pricefield.module
 * add a price field.
 *
 */

 /**
 * Implements hook_field_formatter_info().
 */
function pricefield_field_info() {
  return array(
    'pricefield_format' => array( //Machine name of the formatter
      'label' => t('Price'),
      'field types' => array('text'), //This will only be available to text fields
      'settings'  => array( //Array of the settings we'll create
        'currency' => '$', //give a default value for when the form is first loaded
      ),
      'default_widget' => 'pricefield_field',
      'default_formatter' => 'pricefield_format',
    ),
  );
}

/**
 * Implements hook_field_formatter_settings_form().
 */
function pricefield_field_formatter_settings_form($field, $instance, $view_mode, $form, &$form_state) {
  //This gets the view_mode where our settings are stored
  $display = $instance['display'][$view_mode];
  //This gets the actual settings
  $settings = $display['settings'];
  //Initialize the element variable
  $element = array();
  //Add your select box
  $element['currency'] = array(
    '#type'           => 'textfield',                           // Use a select box widget
    '#title'          => 'Select Currency',                   // Widget label
    '#description'    => t('Select currency used by the field'), // Helper text
    '#default_value'  => $settings['currency'],              // Get the value if it's already been set
  );
  return $element;
}

/**
 * Implements hook_field_formatter_settings_summary().
 */
function pricefield_field_formatter_settings_summary($field, $instance, $view_mode) {
  $display = $instance['display'][$view_mode];
  $settings = $display['settings'];
  $summary = t('The default currency is: @currency ', array(
    '@currency'     => $settings['currency'],
  )); // we use t() for translation and placeholders to guard against attacks
  return $summary;
}

/**
 * Implements hook_field_formatter_view().
 */
function pricefield_field_formatter_view($entity_type, $entity, $field, $instance, $langcode, $items, $display) {
  $element = array(); // Initialize the var
  $settings = $display['settings']; // get the settings
  $currency = $settings['currency']; // Get the currency
  foreach ($items as $delta => $item) {
    $price = $item['safe_value']; // Getting the actual value
  }

  if($price==0){
      $element[0] = array('#markup' => 'Free');
  } else {
      $element[0] = array('#markup' => $currency.' '.$price);
  }
  return $element;
}

function pricefield_field_widget_form(&$form, &$form_state, $field, $instance, $langcode, $items, $delta = 0, $element){
    if ($instance['widget']['type'] == 'pricefield_field') {
        return $element + array(
            '#type' => 'textfield',
            '#size' => 6,
        );
    }
}

function pricefield_widget_info(){
    return array(
    'percentage_field' => array(
    'label' => t('Percentage field'),
    'field types' => array('percentage'),
        ),
    );
}
?>