Model Meta Information

Each model needs some meta-information to initialize. By default you don’t have to define this
information yourself. The model class is smart enough to figure all of the configuration options
out on its own - as long as you follow the frameworks conventions.

However changing the meta-information may be desired in such cases where you are creating a model which needs to access a table which doesn’t follow our conventions.

Defining Meta Information

The following lists all meta-information options that can be changed:

  • name: Name of the model, defaults to the class name.
  • title: The field that is most closely associated with being the title of each record. Defaults to title or name if either of those fields are available.
  • key: The field that acts as the primary key or identifier for a record. Defaults to id if that field is available. The key can also be set using the key() method.
  • source: The table name or document collection being accessed. The default is an all lowercase version of the class name with underscores as spaces. Class names like BlogPost and BlogPosts would default to the blog_posts table.
  • connection: the identifier of the data connection to be used, as defined in the \app\bootstrap\database.php file. Defaults to default.

You may either define the $_meta property on the model class or call the model’s meta() method to
change meta-information. All options will be merged with the defaults.

  1. class Posts extends \lithium\data\Model {
  3.     protected $_meta = [
  4.         'connection' => 'legacy',
  5.         'source' => 'tblPost',
  6.         'key' => 'post_id'
  7.     ];
  8. }
  10. // ... or ...
  12. Posts::meta('key', 'post_id');

Retrieving Meta Information

  1. Posts::meta('source');
  2. Posts::meta('key');
  3. // an alternative for the key is:
  4. Posts::key();

Verifying Model Fields

The hasField() method checks to see if a particular field exists in a model’s schema. This method can check a single field, or return the first field found in an array of multiple options. The parameter is $field, a single field (string) or list of fields (array) to check the existence of.