1: <?php
 2: 
 3: namespace Charcoal\Config;
 4: 
 5: use ArrayAccess;
 6: use JsonSerializable;
 7: use Serializable;
 8: 
 9: /**
10:  * Describes a conceptual data model.
11:  */
12: interface EntityInterface extends
13:     ArrayAccess,
14:     JsonSerializable,
15:     Serializable
16: {
17:     /**
18:      * Gets the data keys on this entity.
19:      *
20:      * @return array
21:      */
22:     public function keys();
23: 
24:     /**
25:      * Gets all data, or a subset, from this entity.
26:      *
27:      * @param  string[] $keys Optional. Extracts only the requested data.
28:      * @return array An associative array.
29:      */
30:     public function data(array $keys = null);
31: 
32:     /**
33:      * Sets data on this entity.
34:      *
35:      * @param  array $data An associative array.
36:      * @return EntityInterface Chainable
37:      */
38:     public function setData(array $data);
39: 
40:     /**
41:      * Determines if this entity contains the specified key and if its value is not NULL.
42:      *
43:      * @param  string $key The data key to check.
44:      * @return boolean TRUE if $key exists and has a value other than NULL, FALSE otherwise.
45:      */
46:     public function has($key);
47: 
48:     /**
49:      * Find an entry of the configuration by its key and retrieve it.
50:      *
51:      * @param  string $key The data key to retrieve.
52:      * @return mixed Value of the requested $key on success, NULL if the $key is not set.
53:      */
54:     public function get($key);
55: 
56:     /**
57:      * Assign a value to the specified key on this entity.
58:      *
59:      * @param  string $key   The data key to assign $value to.
60:      * @param  mixed  $value The data value to assign to $key.
61:      * @return EntityInterface Chainable
62:      */
63:     public function set($key, $value);
64: }
65: