Get Op

This op represents a retrieval operation

This operation returns one specific value, referenced by a key from the resulting expression or a default if specified.

Definition:["get", <key: string, expression(string)>, <result: expression(array)> [, <default: expression(any)>]]

• <key: string | expression(string)> - Key which will be used to search the value by. This key supports full walking through resulting array by using a dot syntax.

For example for an array:

[
  'path' => [
     'to' => [
        'value' => 'this is a value'
     ]
  ]
]

You can return 'this is a value' directly if you use the key path.to.value. If the key does not exist in resulting array in <result: expression(array)>, NULL will be returned unless there is a default expression specified.

You can also specify an expression to be evaluated as a key which must return a string.

• <result: expression(array)> - Expression which will be evaluated which should return an array which can be walked through. This operation will walk through this array to get the requested value from key. If no value is found here, NULL will be returned or a value specified in optional default expression.

• <default: expression(array)> - [Optional value]. If you pass this to the request and nothing can be returned from result expression, this value will be evaluated and it's result returned directly. If this expression is not specified, NULL will be returned.

Usage

Request:

["get", "path.to.value", ["value", {
    "path" : {
        "to" : {
           "value" : "this is a value"
        }
    }
}]]

Response:

"this is a value"

Typical Usage

You would use this operation to return a specific desired result directly from a processed expression.