Adding customs Fields on Drupal module installation: Backup from davsblog.me (http://davsblog.me/drupal-7-field-api-setup-a-new-content-type-o). They delete the example, it helped me to understand the function of adding custom Field during Drupal module installation. See also an example at this page: Drupal 7 Adding Custom Content Type with Custom Fields (Field API)
At the moment we are building a Drupal 7 site which requires everything to be enabled on install via modules / custom profiles. Below is a content type with some extra fields added using Field API so you can see how they are added. This should go in the module *.install file. We go through the standard process of setting up a content type, and call installed_fields and installed_instances functions.
You might want to rename it from ‘article’ to something else, from what I remember on the standard install profile, Drupal 7 already creates a content type called article.
function article_install() { // get the translation function relevant to our current localisation $t = get_t(); // define the content type as an array (same as in hook_node_info()) $article = array( 'type' => 'article', 'name' => $t('Article'), 'base' => 'node_content', 'description' => $t('Content type to handle articles.'), 'body_label' => $t('Article Description'), 'promote' => 0, 'status' => 1, 'comment' => 0, ); // set default values for anything not explicitly defined in the above array $content_type = node_type_set_defaults($article); // add the body field to the content type node_add_body_field($content_type, 'Body'); // create the content type node_type_save($content_type); variable_set('node_options_article', array('status')); // hide comments for this node. http://api.drupal.org/api/drupal/modules--comment--comment.module/7 variable_set('comment_article', 'COMMENT_NODE_HIDDEN'); // Hide date and author information variable_set('node_submitted_article', FALSE); // Create all the fields we are adding to our content type. // http://api.drupal.org/api/function/field_create_field/7 foreach (_article_installed_fields() as $field) { field_create_field($field); } // Create all the instances for our fields. // http://api.drupal.org/api/function/field_create_instance/7 foreach (_article_installed_instances() as $instance) { $instance['entity_type'] = 'node'; $instance['bundle'] = 'article'; field_create_instance($instance); } // adjust the weight so it's called after a dependant module called 'categories' $weight = db_query("SELECT weight FROM {system} WHERE name = :name", array(':name' => 'categories'))->fetchField(); db_update('system')->fields(array( 'weight' => $weight + 1, )) ->condition('name', 'article') ->execute(); } function _article_installed_fields() { $t = get_t(); $fields = array( // text field 'article_source' => array( 'field_name' => 'article_source', 'label' => $t('Artcile Source'), 'cardinality' => 1, 'type' => 'text', 'settings' => array( 'max_length' => 1000, ), ), // taxonomy term reference field, referencing a vocabulary called 'authors' 'article_author' => array( 'field_name' => 'article_author', 'type' => 'taxonomy_term_reference', 'cardinality' => FIELD_CARDINALITY_UNLIMITED, 'settings' => array( 'allowed_values' => array( array( 'vocabulary' => 'authors', 'parent' => 0, ), ), ), ), // node refererence auto complete field (see the instance), referencing a content-type called 'work' 'article_work_ref' => array( 'field_name' => 'article_work_ref', 'label' => $t('Work refrerence'), 'cardinality' => FIELD_CARDINALITY_UNLIMITED, 'type' => 'node_reference', 'settings' => array( 'referenceable_types' => array('work'), ), ), // a text (textarea) field 'article_pullquote' => array( 'field_name' => 'article_pullquote', 'label' => $t('Pull Quote'), 'cardinality' => 1, 'type' => 'text', 'settings' => array( 'max_length' => 1000, ), ), // image field 'article_image' => array( 'field_name' => 'article_image', 'label' => $t('Image'), 'cardinality' => 1, 'type' => 'image', 'settings' => array( 'default_image' => 0, 'uri_scheme' => 'public', ), ), // date field (date module required) 'article_date' => array( 'field_name' => 'article_date', 'label' => $t('Date'), 'cardinality' => 1, 'type' => 'date', ), ); return $fields; } function _article_installed_instances() { $t = get_t(); $instances = array( // instance of the text field above 'article_source' => array( 'field_name' => 'article_source', 'label' => $t('Article Source'), 'cardinality' => 1, 'widget' => array( 'type' => 'text_textfield', 'settings' => array('size' => 60), ), ), // instance of the taxonomy term reference field above 'article_author' => array( 'field_name' => 'article_author', 'entity_type' => 'node', 'label' => $t('Author'), 'bundle' => 'article', 'required' => FALSE, 'widget' => array( 'type' => 'options_select', ), ), // instance of the node reference 'work' auto complete field above 'article_work_ref' => array( 'field_name' => 'article_work_ref', 'label' => $t('Work refrerence'), 'cardinality' => FIELD_CARDINALITY_UNLIMITED, 'widget' => array( 'type' => 'node_reference_autocomplete', ), ), // instance of the textarea field above 'article_pullquote' => array( 'field_name' => 'article_pullquote', 'label' => $t('Pull Quote'), 'cardinality' => 1, 'widget' => array( 'type' => 'text_textarea', 'settings' => array('rows' => 5), ), ), // instance of the image field above 'article_image' => array( 'field_name' => 'article_image', 'label' => $t('Image'), 'cardinality' => 1, 'type' => 'article_image', 'settings' => array( 'alt_field' => 1, 'file_directory' => 'image', 'file_extensions' => 'png gif jpg jpeg', 'max_filesize' => '', 'max_resolution' => '', 'min_resolution' => '', 'title_field' => 1, 'user_register_form' => FALSE, ), 'widget' => array( 'settings' => array( 'preview_image_style' => 'thumbnail', 'progress_indicator' => 'throbber', ), ), 'display' => array( 'default' => array( 'label' => 'hidden', 'type' => 'image', 'settings' => array('image_style' => 'bfi_common_features_image', 'image_link' => ''), 'weight' => -1, ), 'teaser' => array( 'label' => 'hidden', 'type' => 'image', 'settings' => array('image_style' => 'thumbnail', 'image_link' => 'content'), 'weight' => -1, ), ), ), // instance of the date field above 'article_date' => array( 'field_name' => 'article_date', 'label' => $t('Date'), 'cardinality' => 1, 'widget' => array( 'type' => 'date_select', 'settings' => array( 'input_format' => date_default_format('date_select'), 'increment' => 1, 'year_range' => '-3:+3', ), 'behaviors' => array( 'multiple values' => FIELD_BEHAVIOR_CUSTOM, 'default value' => FIELD_BEHAVIOR_CUSTOM, ), ), ), ); return $instances; } function article_uninstall() { // Gather all the example content that might have been created while this // module was enabled. Simple selects still use db_query(). // http://api.drupal.org/api/function/db_query/7 $sql = 'SELECT nid FROM {node} n WHERE n.type = :type'; $result = db_query($sql, array(':type' => 'article')); $nids = array(); foreach ($result as $row) { $nids[] = $row->nid; } // Delete all the nodes at once // http://api.drupal.org/api/function/node_delete_multiple/7 node_delete_multiple($nids); // Loop over each of the fields defined by this module and delete // all instances of the field, their data, and the field itself. // http://api.drupal.org/api/function/field_delete_field/7 foreach (array_keys(_article_installed_fields()) as $field) { field_delete_field($field); } // Delete our content type // http://api.drupal.org/api/function/node_type_delete/7 node_type_delete('article'); // Purge all field information // http://api.drupal.org/api/function/field_purge_batch/7 field_purge_batch(1000); }