This article describes the syntax for accessing and navigating semi-structured data and other complex data structures using Validio API, SDK, and CLI.

JSONPath Expressions

Validio leverages JSONPath to handle semi-structured and other complex data types. Currently, Validio supports a subset of the JSONpath syntax.

This example shows nested data using JSON syntax:

{  
   "agency":"MI6",  
   "user":{  
      "_id":"64591485781fd0a9e07be6c7",  
      "name":"Valencia Walls"  
   },  
   "contact-info":{  
      "company":"CONCILITY",  
      "phone":"+1 (885) 535-3971",  
      "address":"176 Visitation Place, 7052"  
   },  
   "friends":[  
      {  
         "id":0,  
         "name":"Candy Diaz"  
      },  
      {  
         "id":1,  
         "name":"Sherry Burch"  
      }  
   ]  
}

Notation

You can use the dot . notation, bracket notation with single quotes ['...'] or double quotes ["..."], or a combination of both to form expressions. For example, the following expressions are equivalent:

user.name, user["name"], user['name'], ['user']['name'] and ['user'].name

The bracket notation is required when a field contains special characters, such as the hyphen -. For example ['contact-info'].company is a valid expression, but contact-info.company is not a valid expression.

Valid characters in the dot . notation are alphanumeric characters, such as letters and digits, and underscore _. Identifiers that contain other characters require bracket notation.

Unlike most JSONPath dialects, the expressions do not begin with the optional dollar sign $, since an expression always starts from the root field. For example, the column name of a warehouse table. This enables use of the same syntax in expressions for both nested and non-nested data validations.

For example, agency => "M16" works the same regardless if the enclosing record contains nested fields.

Arrays

Validio can perform validations on array fields and on objects nested within array fields.

The array subscript [] notation selects a specific element in an array. For example, the following expression selects the element with id 1 in the friends array field:

friends[1].name => "Sherry Burch"

The syntax supports functions on arrays with the parenthesis () at the end of an expression. For example, the following expressions are equivalent:

friends.length(), friends['length']() => 2

The invoked function is the array length function, which results in the number of elements in the array.

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Currently, the JSONPath syntax only supports the length function for arrays.