Schema Reference

Schema Reference

Keys

Every schema key becomes a key of the result, in the same order. Integer keys, 0 and '' are valid keys, so a list schema produces a list:

Mapper::map($data, ['@data/a', '@data/b', 'static']);
// ['A', 'B', 'static']

A key ending with [] marks a collection. The suffix is removed from the result key. [] anywhere else in a key has no special meaning.

Values

Schema value	Result
'@data/'	The whole source document
'@data/user/name'	Value at user/name
'@data/items/0/sku'	Value of sku in the first item
'@data/items/*/sku'	List with one entry per item; null where the item has no sku
Nested array	Mapped recursively with the same callback and default
Any other value	Copied unchanged (strings, numbers, booleans, null, objects)

Notes:

• The prefix is case-sensitive and must be at the start of the string: '@DATA/a' and 'x @data/a' are copied as plain strings.
• Paths use / as separator. See the StrObj path documentation for every path feature.
• Stored values are returned unchanged, including false, 0, '' and null. Paths that do not exist return the default; see Missing Values and Defaults.

Constants

Constant	Value
Mapper::DATA_PREFIX	'@data/'
Mapper::COLLECTION_SUFFIX	'[]'

Use them to build schemas programmatically:

$schema = ['name' => Mapper::DATA_PREFIX . 'user/name'];