field.crud.inc 21.5 KB
Newer Older
Dries's avatar
 
Dries committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558
<?php

class FieldException extends Exception {}

/**
 * @defgroup field_structs Field API data structures
 * @{
 * Represent Field API fields and instances.
 *
 * The Field API defines two primary data structures, Field and
 * Instance, and the concept of a Bundle.  A Field defines a
 * particular type of data that can be attached to objects.  A Field
 * Instance is a Field attached to a single Bundle.  A Bundle is a set
 * of fields that are treated as a group by the Field Attach API.
 *
 * For example, suppose a site administrator wants Article nodes to
 * have a subtitle and photo.  Using the Field API or some UI module,
 * the administrator creates a field named 'subtitle' of type 'text'
 * and a field named 'photo' of type 'image'.  The administrator
 * (again, via a UI) creates two Field Instances, one attaching the
 * field 'subtitle' to the bundle 'article' and one attaching the field
 * 'photo' to the bundle 'article'.  When the node system uses the
 * Field Attach API to load all fields for an Article node, it passes
 * the node's content type (which is 'article') as the node's bundle.
 * field_attach_load() then loads the 'subtitle' and 'photo' fields
 * because they are both attached to the bundle 'article'.
 *
 * Field objects are (currently) represented as an array of key/value
 * pairs.  The object properties are:
 *
 * @param array $field:
 * - field_name (string)
 *     The name of the field.  Each field name is unique within Field API.
 *     When a field is attached to an object, the field's data is stored
 *     in $object->$field_name.
 * - type (string)
 *     The type of the field, such as 'text' or 'image'.  Field types
 *     are defined by modules that implement hook_field_into().
 * - cardinality (integer)
 *     The number of values the field can hold.  Legal values are any
 *     positive integer or FIELD_CARDINALITY_UNLIMITED.
 * - locked (integer)
 *     TODO: undefined.
 * - module (string, read-only)
 *     The name of the module that implements the field type.
 * - active (integer, read-only)
 *     TRUE if the module that implements the field type is currently
 *     enabled, FALSE otherwise.
 * - deleted (integer, read-only)
 *     TRUE if this field has been deleted, FALSE otherwise.  Deleted
 *     fields are ignored by the Field Attach API. This property exists
 *     because fields can be marked for deletion but only actually
 *     destroyed by a separate garbage-collection process.
 * - columns (array, read-only).
 *     An array of the Field API columns used to store each value of
 *     this field.  The column list may depend on field settings; it is
 *     not constant per field type.  Field API column specifications are
 *     exactly like Schema API column specifications but, depending on
 *     the field storage module in use, the name of the column may not
 *     represent an actual column in an SQL database.
 * - settings (array)
 *     A sub-array of key/value pairs of field-type-specific settings.  Each
 *     field type module defines and documents its own field settings.
 *
 * Field Instance objects are (currently) represented as an array of
 * key/value pairs.  The object properties are:
 *
 * @param array $instance:
 * - field_name (string)
 *     The name of field attached by this instance.
 * - bundle (string)
 *     The name of the bundle that the field is attached to.
 * - label (string)
 *     A human-readable label for the field when used with this
 *     bundle.  For example, the label will be the title of Form API
 *     elements for this instance.
 * - description (string)
 *     A human-readable description for the field when used with this
 *     bundle.  For example, the description will be the help text of
 *     Form API elements for this instance.
 * - weight (float)
 *     The order in which the field should be sorted relative
 *     to other fields when used with this bundle.  The weight affects
 *     ordering in both forms (see field_attach_form()) and rendered output
 *     (see field_attach_view()).
 *     TODO - this should probably become a context setting so that
 *     the weight can be different in the form and in various other
 *     contexts.
 * - required (integer)
 *     TRUE if a value for this field is required when used with this
 *     bundle, FALSE otherwise.  Currently, required-ness is only enforced
 *     during Form API operations, not by field_attach_load(),
 *     field_attach_insert(), or field_attach_update().
 * - default_value_function (string)
 *     The name of the function, if any, that will provide a default value.
 * - deleted (integer, read-only)
 *     TRUE if this instance has been deleted, FALSE otherwise.
 *     Deleted instances are ignored by the Field Attach API.
 *     This property exists because instances can be marked for deletion but
 *     only actually destroyed by a separate garbage-collection process.
 * - settings (array)
 *     A sub-array of key/value pairs of field-type-specific instance
 *     settings.  Each field type module defines and documents its own
 *     instance settings.
 * - widget (array)
 *     A sub-array of key/value pairs identifying the Form API input widget
 *     for the field when used by this bundle.
 *     - type (string)
 *         The type of the widget, such as text_textfield.  Widget types
 *         are defined by modules that implement hook_field_widget_info().
 *     - module (string, read-only)
 *         The name of the module that implements the widget type.
 *     - active (integer, read-only)
 *         TRUE if the module that implements the widget type is currently
 *         enabled, FALSE otherwise.
 *     - settings (array)
 *         A sub-array of key/value pairs of widget-type-specific settings.
 *         Each field widget type module defines and documents its own
 *         widget settings.
 * - display (array)
 *     A sub-array of key/value pairs identifying display contexts
 *     and the way the field should be displayed in that context.
 *     TODO more work to do here.
 *     - (context_1)
 *       - label
 *       - exclude
 *       - type
 *       - settings
 *         - ...
 *       - module (internal)
 *     - (context 2)
 *       - ...
 *
 * TODO D7 : document max length for field types, widget types,
 * formatter names...
 */
/**
 * @} End of "defgroup field_structs".
 */

/**
 * @defgroup field_crud Field CRUD API
 * @{
 * Create, update, and delete Field API fields, bundles, and instances.
 *
 * Modules use this API, often in hook_install(), to create custom
 * data structures.  UI modules will use it to create a user interface.
 *
 * The Field CRUD API uses
 * @link field_structs Field API data structures @endlink.
 */

/**
 * Create a field.  This function does not bind the field to any
 * bundle; use field_create_instance for that.
 *
 * @param $field
 *   A field structure.  The field_name and type properties are required.
 * @throw
 *   FieldException
 */
function field_create_field($field) {
  // Field name is required.
  if (empty($field['field_name'])) {
    throw new FieldException('Attempt to create an unnamed field.');
  }
  // Field name cannot contain invalid characters.
  if (preg_match('/[^a-z0-9_]/', $field['field_name'])) {
    throw new FieldException('Attempt to create a field with invalid characters. Only alphanumeric characters and underscores are allowed.');
  }

  // TODO: check that field_name < 32 chars.

  // Check that the field type is known.
  $field_type = field_info_field_types($field['type']);
  if (!$field_type) {
    throw new FieldException(t('Attempt to create a field of unknown type %type.', array('%type' => $field['type'])));
  }

  // Ensure the field name is unique. We also check disabled or deleted fields.
  // TODO : do we want specific messages when clashing with a disabled or inactive field ?
  $prior_field = field_read_field($field['field_name'], array('include_inactive' => TRUE, 'include_deleted' => TRUE));
  if (!empty($prior_field)) {
    throw new FieldException(t('Attempt to create field name %name which already exists.', array('%name' => $field['field_name'])));
  }

  $field += array(
    'cardinality' => 1,
    'locked' => FALSE,
    'settings' => array(),
  );
  $module = $field_type['module'];
  // Create all per-field-type properties (needed here as long as we have
  // settings that impact column definitions).
  $field['settings'] += field_info_field_settings($field['type']);
  $field['module'] = $module;
  $field['active'] = 1;
  $field['deleted'] = 0;
  // Create the data table. We need to populate the field columns, even though
  // we don't actually store them.
  $field['columns'] = (array) module_invoke($field['module'], 'field_columns', $field);
  module_invoke(variable_get('field_storage_module', 'field_sql_storage'), 'field_storage_create_field', $field);

  drupal_write_record('field_config', $field);

  // Clear caches
  field_cache_clear(TRUE);
}

/**
 * Read a single field record directly from the database.  Generally,
 * you should use the field_info_field() instead.
 *
 * @param $field_name
 *   The field name to read.
 * @param array $include_additional
 *   The default behavior of this function is to not return a field that
 *   is inactive or has been deleted. Setting
 *   $include_additional['include_inactive'] or
 *   $include_additional['include_deleted'] to TRUE will override this
 *   behavior.
 * @return
 *   A field structure, or FALSE.
 */
function field_read_field($field_name, $include_additional = array()) {
  $fields = field_read_fields(array('field_name' => $field_name), $include_additional);
  return $fields ? current($fields) : FALSE;
}

/**
 * Read in fields that match an array of conditions.
 *
 * @param array $params
 *   An array of conditions to match against.
 * @param array $include_additional
 *   The default behavior of this function is to not return fields that
 *   are inactive or have been deleted. Setting
 *   $include_additional['include_inactive'] or
 *   $include_additional['include_deleted'] to TRUE will override this
 *   behavior.
 * @return
 *   An array of fields matching $params.
 */
function field_read_fields($params = array(), $include_additional = array()) {
  $query = db_select('field_config', 'fc', array('fetch' => PDO::FETCH_ASSOC));
  $query->fields('fc');

  // Turn the conditions into a query.
  foreach ($params as $key => $value) {
    $query->condition($key, $value);
  }
  if (!isset($include_additional['include_inactive']) || !$include_additional['include_inactive']) {
    $query->condition('fc.active', 1);
  }
  if (!isset($include_additional['include_deleted']) || !$include_additional['include_deleted']) {
    $query->condition('fc.deleted', 0);
  }

  $fields = array();
  $results = $query->execute();
  foreach ($results as $field) {
    // drupal_write_record() writes an empty string for empty arrays.
    $field['settings'] = $field['settings'] ? unserialize($field['settings']) : array();

    module_invoke_all('field_read_field', $field);

    // Populate storage columns.
    $field['columns'] = (array) module_invoke($field['module'], 'field_columns', $field);

    $fields[$field['field_name']] = $field;
  }
  return $fields;
}

/**
 * Mark a field for deletion, including all its instances and all data
 * associated with it.
 *
 * @param $field_name
 *   The field name to delete.
 */
function field_delete_field($field_name) {
  // Mark the field for deletion.
  db_update('field_config')
    ->fields(array('deleted' => 1))
    ->condition('field_name', $field_name)
    ->execute();

  // Mark any instances of the field for deletion.
  db_update('field_config_instance')
    ->fields(array('deleted' => 1))
    ->condition('field_name', $field_name)
    ->execute();
  module_invoke(variable_get('field_storage_module', 'field_sql_storage'), 'field_storage_delete_field', $field_name);
  // Clear the cache.
  field_cache_clear(TRUE);
}

/**
 * Creates an instance of a field, binding it to a bundle.
 *
 * @param $instance
 *   A field instance structure.  The field_name and bundle properties
 *   are required.
 * @throw
 *   FieldException
 */
function field_create_instance($instance) {
  // Check that the specified field exists.
  $field = field_read_field($instance['field_name']);
  if (empty($field)) {
    throw new FieldException("Attempt to create an instance of a field that doesn't exist.");
  }

  // TODO: Check that the specifed bundle exists.

  // TODO: Check that the widget type is known and can handle the field type ?
  // TODO: Check that the formatters are known and can handle the field type ?
  // TODO: Check that the display build modes are known for the object type ?
  // Those checks should probably happen in _field_write_instance() ?
  // Problem : this would mean that a UI module cannot update an instance with a disabled formatter.

  // Ensure the field instance is unique.
  // TODO : do we want specific messages when clashing with a disabled or inactive instance ?
  $prior_instance = field_read_instance($instance['field_name'], $instance['bundle'], array('include_inactive' => TRUE, 'include_deleted' => TRUE));
  if (!empty($prior_instance)) {
    throw new FieldException('Attempt to create a field instance which already exists.');
  }

  _field_write_instance($instance);

  module_invoke_all('field_create_instance', $instance);

  // Clear caches
  field_cache_clear();
  return FALSE;
}

/*
 * Update an instance of a field.
 *
 * @param $instance
 *   An associative array represeting an instance structure. The required
 *   keys and values are:
 *     field_name:  The name of an existing field.
 *     bundle:  The bundle this field belongs to.
 *   Any other properties specified in $instance overwrite the
 *   existing values for the instance.
 * @throw
 *   FieldException
 * @see field_create_instance()
 */
function field_update_instance($instance) {
  // Check that the specified field exists.
  $field = field_read_field($instance['field_name']);
  if (empty($field)) {
    throw new FieldException("Attempt to update an instance of a nonexistent field.");
  }

  // Check that the field instance exists (even if it is inactive, since we
  // want to be able to replace inactive widgets with new ones).
  $prior_instance = field_read_instance($instance['field_name'], $instance['bundle'], array('include_inactive' => TRUE));
  if (empty($prior_instance)) {
    throw new FieldException("Attempt to update a field instance that doesn't exist.");
  }

  _field_write_instance($instance, TRUE);

  // Clear caches.
  field_cache_clear();
}

/**
 * Store an instance record in the field configuration database.
 *
 * @param $instance
 *   An instance structure.
 * @param $update
 *   Whether this is a new or existing instance.
 */
function _field_write_instance($instance, $update = FALSE) {
  $field = field_read_field($instance['field_name']);
  $field_type = field_info_field_types($field['type']);

  // Set defaults.
  $instance += array(
    'settings' => array(),
    'display' => array(),
    'widget' => array(),
    'required' => FALSE,
    'label' => $instance['field_name'],
    'description' => '',
    'weight' => 0,
    'deleted' => 0,
  );

  // Set default instance settings.
  $instance['settings'] += field_info_instance_settings($field['type']);

  // Set default widget and settings.
  $instance['widget'] += array(
    // TODO: what if no 'default_widget' specified ?
    'type' => $field_type['default_widget'],
    'settings' => array(),
  );
  // Check widget module.
  $widget_type = field_info_widget_types($instance['widget']['type']);
  $widget_module = $widget_type['module'];
  $widget_active = module_exists($widget_module);
  $instance['widget']['settings'] += field_info_widget_settings($instance['widget']['type']);
  $instance['widget']['module'] = $widget_module;
  $instance['widget']['active'] = $widget_active;

  // Make sure there is at least display info for the 'full' context.
  $instance['display'] += array(
    'full' => array(),
  );
  // Set default display settings for each context.
  foreach ($instance['display'] as $context => $display) {
    $instance['display'][$context] += array(
      'label' => 'above',
      'exclude' => 0,
      // TODO: what if no 'default_formatter' specified ?
      'type' => $field_type['default_formatter'],
      'settings' => array(),
    );
    $formatter_type = field_info_formatter_types($instance['display'][$context]['type']);
    // TODO : 'hidden' will raise PHP warnings.
    $instance['display'][$context]['module'] = $formatter_type['module'];
    $instance['display'][$context]['settings'] += field_info_formatter_settings($instance['display'][$context]['type']);
  }

  // Create $data to contain everything from $instance that does not
  // have its own column, and thus will be stored serialized.
  $data = $instance;
  unset($data['field_name'], $data['bundle'], $data['widget']['type'], $data['weight'], $data['deleted']);

  $record = array(
    'field_name' => $instance['field_name'],
    'bundle' => $instance['bundle'],
    'widget_type' => $instance['widget']['type'],
    'widget_module' => $widget_module,
    'widget_active' => $widget_active,
    'weight' => $instance['weight'],
    'data' => $data,
    'deleted' => $instance['deleted'],
  );
  // We need to tell drupal_update_record() the primary keys to trigger an
  // update.
  $primary_keys = $update ? array('field_name', 'bundle') : array();
  drupal_write_record('field_config_instance', $record, $primary_keys);
}

/**
 * Read a single instance record directly from the database.  Generally,
 * you should use the field_info_instance() instead.
 *
 * @param $field_name
 *   The field name to read.
 * @param $bundle
 *   The bundle to which the field is bound.
 * @param array $include_additional
 *   The default behavior of this function is to not return an instance that
 *   is inactive or has been deleted. Setting
 *   $include_additional['include_inactive'] or
 *   $include_additional['include_deleted'] to TRUE will override this
 *   behavior.
 * @return
 *   An instance structure, or FALSE.
 */
function field_read_instance($field_name, $bundle, $include_additional = array()) {
  $instances = field_read_instances(array('field_name' => $field_name, 'bundle' => $bundle), $include_additional);
  return $instances ? current($instances) : FALSE;
}

/**
 * Read in field instances that match an array of conditions.
 *
 * @param $param
 *   An array of properties to use in selecting a field
 *   instance. Valid keys include any column of the
 *   field_config_instance table.  If NULL, all instances will be returned.
 * @param $include_additional
 *   The default behavior of this function is to not return field
 *   instances that are inactive or have been marked deleted. Setting
 *   $include_additional['include_inactive'] or
 *   $include_additional['include_deleted'] to TRUE will override this
 *   behavior.
 * @return
 *   An array of instances matching the arguments.
 */
function field_read_instances($params = array(), $include_additional = array()) {
  $query = db_select('field_config_instance', 'fci', array('fetch' => PDO::FETCH_ASSOC));
  $query->join('field_config', 'fc', 'fc.field_name = fci.field_name');
  $query->fields('fci');
  #$query->fields('fc', array('type'));

  // Turn the conditions into a query.
  foreach ($params as $key => $value) {
    $query->condition('fci.' . $key, $value);
  }
  $query->condition('fc.active', 1);
  if (!isset($include_additional['include_inactive']) || !$include_additional['include_inactive']) {
    $query->condition('fci.widget_active', 1);
  }
  if (!isset($include_additional['include_deleted']) || !$include_additional['include_deleted']) {
    $query->condition('fc.deleted', 0);
    $query->condition('fci.deleted', 0);
  }

  $instances = array();
  $results = $query->execute();

  foreach ($results as $record) {
    $instance = unserialize($record['data']);
    $instance['field_name'] = $record['field_name'];
    $instance['bundle'] = $record['bundle'];
    $instance['weight'] = $record['weight'];
    $instance['deleted'] = $record['deleted'];
    $instance['widget']['type'] = $record['widget_type'];
    $instance['widget']['module'] = $record['widget_module'];
    $instance['widget']['active'] = $record['widget_active'];

    // TODO D7 : Set default widget settings, default instance settings, default display settings.
    // (the modules that defined them might have changed since the instance was last saved).

    module_invoke_all('field_read_instance', $instance);
    $instances[] = $instance;
  }
  return $instances;
}

/**
 * Mark a field instance for deletion, including all data associated with
 * it.
 *
 * @param $field_name
 *   The name of the field whose instance will be deleted.
 * @param $bundle
 *   The bundle for the instance which will be deleted.
 */
function field_delete_instance($field_name, $bundle) {
  // Mark the field instance for deletion.
  db_update('field_config_instance')
    ->fields(array('deleted' => 1))
    ->condition('field_name', $field_name)
    ->condition('bundle', $bundle)
    ->execute();

  // Mark all data associated with the field for deletion.
  module_invoke(variable_get('field_storage_module', 'field_sql_storage'), 'field_storage_delete_instance', $field_name, $bundle);
  // Clear the cache.
  field_cache_clear();
}

/**
 * @} End of "defgroup field_crud".
 */