farmOS/farm_log.module

<?php
/**
 * @file
 * Code for the Farm Log feature.
 */

// Include Features code.
include_once 'farm_log.features.inc';

/**
 * Implements hook_permission().
 */
function farm_log_permission() {
  return array(
    'view farm logs' => array(
      'title' => t('View farm logs'),
      'description' => t('View all farm-related log items.'),
    ),
  );
}

/**
 * Implements hook_farm_access_perms().
 */
function farm_log_farm_access_perms($role) {
  $perms = array();

  // Grant access to view farm logs.
  $perms[] = 'view farm logs';

  return $perms;
}

/**
 * Implements hook_farm_admin_actions().
 */
function farm_log_farm_admin_actions() {

  // Define farm area actions.
  $actions = array(
    'log' => array(
      'title' => t('Add a log'),
      'href' => 'log/add',
      'paths' => array(
        'farm',
        'farm/logs',
      ),
      'weight' => 1,
    ),
  );
  return $actions;
}

/**
 * Implements hook_form_alter().
 */
function farm_log_form_alter(&$form, &$form_state, $form_id) {

  // If this is a log form...
  if ($form_id == 'log_form') {

    // If there is an asset(s) reference field.
    if (!empty($form['field_farm_asset'])) {

      // Alter the form using our helper function.
      farm_log_form_prepopulate_asset($form, 'field_farm_asset');
    }

    // If there is an area(s) reference field...
    if (!empty($form['field_farm_area'])) {

      // Alter the form with the farm_log helper function.
      farm_log_form_prepopulate_area($form, 'field_farm_area');
    }
  }
}

/**
 * Implements hook_entityreference_view_widget_views_arguments_alter().
 */
function farm_crop_entityreference_view_widget_views_arguments_alter(&$arguments, $form_state, $view) {

  // This module provides a View that is used for searching and selecting assets
  // for the field_farm_asset entity reference field, using the Entity
  // Reference View Widget module.
  //
  // In some cases, we want to limit what shows up in the View of assets, based
  // on the log type that the field is on. For instance, a seeding should only
  // be able to reference planting assets, but it still uses the general
  // field_farm_asset field, which technically can reference any asset type.
  //
  // The Entity Reference View Widget module provides this hook to allow the
  // View arguments to be altered. We implement this hook, and invoke our own
  // custom hook to allow farmOS modules to filter the View results to a
  // specific entity type, given the current log type.
  //
  // The View that we use is farm_asset_entityreference_view, which has two
  // contextual arguments: asset id (to filter out already-selected assets), and
  // asset type. The code below only tries to set the asset type argument, and
  // maintains any asset id argument that is already set.

  /**
   * @todo
   * Note that this does NOT alter the "Asset type" exposed filter. So users
   * will still see that filter, and it will still default to "- Any -". If
   * the contextual filter is activated here, however, then selecting any other
   * asset type with the exposed filter will return an empty result set. That's
   * confusing, so perhaps we should find a way to hide that exposed filter if
   * this code successfully sets a contextual filter argument.
   */

  // Figure out what the log type is.
  if (!empty($form_state['build_info']['args'][0]->type)) {
    $log_type = $form_state['build_info']['args'][0]->type;
  }

  // If that failed, bail.
  else {
    return;
  }

  // Ask modules if we should limit the asset type.
  $limit_types = module_invoke_all('farm_log_allowed_asset_reference_type', $log_type);

  // The asset type argument only supports a single value, so we're just going
  // to take the first one.
  if (!empty($limit_types[0])) {
    $type = $limit_types[0];
  }

  // If a type was not found, bail.
  if (empty($type)) {
    return;
  }

  // We need to ensure that the first argument is reserved for asset id(s). So
  // if it's not set, set it to 'all'.
  if (empty($arguments)) {
    $arguments[0] = 'all';
  }

  // Add the asset type as the second argument.
  $arguments[1] = $type;
}

/**
 * Implements hook_entity_presave().
 */
function farm_log_entity_presave($entity, $type) {

  // When a log is saved, populate the Geometry field if available.
  if ($type == 'log') {

    // In the case of movement logs, the area reference field name is
    // 'field_farm_move_to'.
    /**
     * @todo
     * Migrate field_farm_move_to to field_farm_area? Currently farm_log depends
     * on farm_log_movement, but if that needs to change in the future this will
     * also need to change.
     */
    $area_field = 'field_farm_area';
    if ($entity->type == 'farm_movement') {
      $area_field = 'field_farm_move_to';
    }
    farm_log_geometry_populate($entity, $area_field);
  }
}

/**
 * Populate the geometry of logs from the area(s) they reference, if no
 * geometry is already defined.
 *
 * @param Log $log
 *   The log entity.
 * @param string $area_field
 *   Optionally, the machine name of the area reference field to look for.
 *   Defaults to 'field_farm_area'.
 */
function farm_log_geometry_populate(&$log, $area_field = 'field_farm_area') {

  // If the log doesn't have an area reference field, bail.
  if (!isset($log->{$area_field})) {
    return;
  }

  // If a geometry is already defined, bail.
  if (!empty($log->field_farm_geofield[LANGUAGE_NONE][0]['geom'])) {
    return;
  }

  // Load the area(s) referenced by the area reference field.
  $areas = array();
  if (!empty($log->{$area_field}[LANGUAGE_NONE])) {
    foreach ($log->{$area_field}[LANGUAGE_NONE] as $area_reference) {
      if (!empty($area_reference['tid'])) {
        $areas[] = taxonomy_term_load($area_reference['tid']);
      }
    }
  }

  // If no areas are referenced, bail.
  if (empty($areas)) {
    return;
  }

  // Iterate over the areas to find geometries.
  $geoms = array();
  foreach ($areas as $area) {
    if (!empty($area->field_farm_geofield[LANGUAGE_NONE][0]['geom'])) {
      $geoms[] = $area->field_farm_geofield[LANGUAGE_NONE][0]['geom'];
    }
  }

  // Populate the geofield.
  farm_map_geofield_populate($log, $geoms);
}

/**
 * Helper function for enabling asset prepopulation in log forms.
 *
 * @param array $form
 *   The form array to modify, passed by reference.
 * @param string $field_name
 *   The machine name of the entity reference field that should be populated.
 *
 * @return array|bool
 *   Returns the asset objects in an array, if found, FALSE otherwise.
 */
function farm_log_form_prepopulate_asset(array &$form, $field_name = 'field_farm_asset') {

  // Load assets from the ?farm_asset query parameter.
  $assets = farm_asset_load_assets_from_url();

  // If there are no assets, bail.
  if (empty($assets)) {
    return FALSE;
  }

  // Load the field instance definition.
  $entity_type = $form['#entity_type'];
  $bundle = $form['#bundle'];
  $field_instance = field_info_instance($entity_type, $field_name, $bundle);

  // If the widget type is "radios/checkboxes" or "select list"...
  if (in_array($field_instance['widget']['type'], array('options_buttons', 'options_select'))) {

    // Build a list of asset ID.
    $asset_ids = array();
    foreach ($assets as $asset) {
      $asset_ids[] = $asset->id;
    }

    // Use the array of asset IDs as the field's default value.
    if (empty($form[$field_name][LANGUAGE_NONE]['#default_value'])) {
      $form[$field_name][LANGUAGE_NONE]['#default_value'] = $asset_ids;
    }
  }

  // If the widget type is "autocomplete" or "autocomplete tags"...
  elseif (in_array($field_instance['widget']['type'], array('entityreference_autocomplete', 'entityreference_autocomplete_tags'))) {

    // Build a list of asset labels in the format that the widget expects.
    $asset_labels = array();
    foreach ($assets as $asset) {
      $asset_labels[] = entity_label('farm_asset', $asset) . ' (' . $asset->id . ')';
    }

    // For "autocomplete", add each one as a separate field.
    if ($field_instance['widget']['type'] == 'entityreference_autocomplete') {
      foreach ($asset_labels as $key => $label) {

        // If the item isn't empty, skip it.
        if (!empty($form[$field_name][LANGUAGE_NONE][$key]['target_id']['#default_value'])) {
          continue;
        }

        /**
         * @todo
         * This seems to be the easiest way to autopopulate entityreference_autocomplete
         * widgets, but it is MESSY! If anyone can figure out a better way, I will buy
         * you a beer.
         */
        // Copy the initial array structure from the first element.
        $form[$field_name][LANGUAGE_NONE][$key] = $form[$field_name][LANGUAGE_NONE][0];

        // Set the default, delta, and weight values.
        $form[$field_name][LANGUAGE_NONE][$key]['target_id']['#default_value'] = $label;
        $form[$field_name][LANGUAGE_NONE][$key]['target_id']['#delta'] = $key;
        $form[$field_name][LANGUAGE_NONE][$key]['target_id']['#weight'] = $key;

        // Only make the first one required.
        if ($key > 0) {
          $form[$field_name][LANGUAGE_NONE][$key]['target_id']['#required'] = 0;
        }

        $form[$field_name][LANGUAGE_NONE]['#max_delta'] = $key;
        $form[$field_name][LANGUAGE_NONE][$key]['_weight']['#delta'] = $key;
        $form[$field_name][LANGUAGE_NONE][$key]['_weight']['#default_value'] = $key;
      }
    }

    // For "autocomplete tags", implode them all into one comma-separated list.
    elseif ($field_instance['widget']['type'] == 'entityreference_autocomplete_tags') {
      if (empty($form[$field_name][LANGUAGE_NONE]['#default_value'])) {
        $form[$field_name][LANGUAGE_NONE]['#default_value'] = implode(', ', $asset_labels);
      }
    }
  }

  // If the widget type is "entity reference view widget"...
  elseif ($field_instance['widget']['type'] == 'entityreference_view_widget') {

    // Add a set of checkbox form elements, as the entityreference_view_widget
    // module expects...
    foreach ($assets as $key => $asset) {

      // If the item isn't empty, skip it.
      if (!empty($form[$field_name][LANGUAGE_NONE][$key]['target_id'])) {
        continue;
      }

      // Add the checkbox element.
      $form[$field_name][LANGUAGE_NONE][$key]['target_id'] = array(
        '#type' => 'checkbox',
        '#return_value' => $asset->id,
        '#value' => $asset->id,
        '#title_display' => 'after',
        '#attributes' => array(
          'checked' => 'checked',
        ),
        '#title' => entity_label('farm_asset', $asset),
      );
    }
  }

  return $assets;
}

/**
 * Helper function for enabling area prepopulation in log forms.
 *
 * @param array $form
 *   The form array to modify, passed by reference.
 * @param string $field_name
 *   The machine name of the term reference field that should be populated.
 *
 * @return TaxonomyTerm term
 *   Returns the taxonomy term object, if found.
 */
function farm_log_form_prepopulate_area(array &$form, $field_name = 'field_farm_area') {
  $area = NULL;

  // Alias for the field's default value.
  $field_value = &$form[$field_name][LANGUAGE_NONE]['#default_value'];

  // If the "farm_area" query parameter is set...
  $params = drupal_get_query_parameters();
  if (!empty($params['farm_area'])) {

    // Verify that the farm_area is valid.
    $area = taxonomy_term_load($params['farm_area']);
    if ($area) {

      // Add the area to the form.
      $form['farm_area'] = array(
        '#type' => 'value',
        '#value' => $area,
      );

      // Prepopulate the area reference field.
      if (empty($field_value)) {
        $field_value = $area->tid;
      }
    }
  }

  return $area;
}