The $pragma keyword is used to override settings for the current execution context. The value of the $pragma keyword must be an object. Available properties are described below.

You can disable $pragma keyword by setting the allowPragmas option to false.

globals

Sets the current global variables.

{
  "$pragma": {
    "globals": {
      "VALUE-1": 1,
      "OTHER-GLOBAL": "something"
    }
  }
}

slots

Sets the current slots. If a slot value is passed as a string, a slot with that name is search and used if exists.

{
  "$pragma": {
    "slots": {
      "part-mail": {"format": "email"},
      "part-props": "some-existing-slot-name"
    }
  }
}

maxErrors

Overrides the maxErrors setting. The value must be a positive integer.

cast

Converts current value by applying a cast. The value must be a string representing a JSON data type name (except null).

{
  "$pragma": {
    "cast": "number"
  },
  "type": "number",
  "minimum": 5
}

If you send "5.1" (string), the value will be converted to 5.1 (float) and then validated. Without the cast, an error is returned by the type keyword.

The following table describes various casts.

If a conversion is not available, the value is converted to null.

From	To	Result
null	number	0 - zero
null	integer	0 - zero
null	boolean	false
null	string	"" - empty string
null	array	[] - empty array
null	object	null
number	number	same value
number	integer	truncates number, 5.1 => 5
number	boolean	false if 0, true otherwise
number	string	string representation, 5.1 => "5.1"
number	array	5.1 => [5.1]
number	object	null
integer	number	same value
integer	integer	same value
integer	boolean	false if 0, true otherwise
integer	string	string representation, 5 => "5"
integer	array	5 => [5]
integer	object	null
boolean	number	true => 1, false => 0
boolean	integer	true => 1, false => 0
boolean	boolean	same value
boolean	string	true => "1", false => "" - empty string
boolean	array	true => [true], false => false
boolean	object	null
string	number	try to parse the number from string, 0 if invalid number representation
string	integer	try to parse the integer from string, 0 if invalid number representation
string	boolean	empty string => false, otherwise true
string	string	same value
string	array	"str" => ["str"]
string	object	null
array	number	null
array	integer	null
array	boolean	empty array => false, otherwise true
array	string	null
array	array	same value
array	object	object representation, [1, "abc"] => {"0": 1, "1": "abc"}
object	number	null
object	integer	null
object	boolean	empty object => false, otherwise true
object	string	null
object	array	object values, {"key1": 1, "key2": "value 2"} => [1, "value 2"]
object	object	same value