xjot: An extensible object type validation tool

Overview

xjot is a type validation library to accelerate the data validation in RESTful APIS.

To use xjot:

• Define your object template
• Use the template to validate objects

Basic use

    let contactT = xjot.object {
        firstName : xjot.string( { required: true, maxLength: 18, autoTruncate: true }),
        lastName : xjot.string( { required: true, maxLength: 18, autoTruncate: true }),
        age: xjot.int( required: false, min:1, max: 77 )
    }    

    myObject = { firstName: "John", lastName = "Doe"}

    console.log(JSON.stringify(contactT.validate(myObject),undefined,4 ))

xjot will not only check the field values. It will also perform type convesion and modify the values based on the formatting parameters provided.

Template reference

Creating a template

A template is an object that contains describes what rules objects of this kind must follow. A template is different from a class in that a class describes how to create new instances of an object. A template describes the validation rules for the data in that object, as well as some transformations to be applied to the data during validation.

  // For simple types
  myfield = xjot.<type>( {rules} )

  // For object 
  myTemplate = xjot.<type>( {fieldsDefinition} [, {rules}] )

Types

xjot currently supports the following types:

• int: integer (value will be truncated) or string that can be converted to a number
• number: any number or string that can be converted to a number
• boolean: any value that can be interpreted as a boolean (true, false, Y, N, 1, 0)
• date: a string that meets the defined criteria, or string that can be converted to a date
• string: a string that meets the defined criteria
• object: an object composed of any of the xjot types
• array: and array of any of the xjot types

Template rules

• required: indicates if a field must be present and not undefined (Default false)
• default: when undefined, default value to use
• acceptNull: true if a "null" value is accepted (Default false)
• min, max: boundaries for numbers
• maxLength: maximum length for string values
• autoTruncate: if true, string value will be truncated to maxLength
• values: an list of accepted values in an array
• dbfield: mapped SQL database field for automatic SQL generation (Applies to simple types).
• autoIncrement: indicates the underlying database field is not writable.
• primaryKey: indicates this field is to be used ar primary key in update SQL.
• table: mapped SQL database table for automatic SQL generation (Applies to object types ).

Object definitions

The object template definition is an object whose keys are the field name of the objects to check and the values are instances of the field types

Example

    let addressT = xjot.object({
      line1:   xjot.string( { required: true, maxLength: 80, autoTruncate: true ),
      line2:   xjot.string( { required: false, maxLength: 80, autoTruncate: true ),
      line3:   xjot.string( { required: false, maxLength: 80, autoTruncate: true ),
      zipcode: xjot.string( { required: true, maxLength: 20, autoTruncate: true ),
      city:    xjot.string( { required: true, maxLength: 50, autoTruncate: true ),
      state:   xjot.string( { required: false, maxLength: 30, autoTruncate: true ),
      country: xjot.string( { required: true, maxLength: 30, autoTruncate: true ),
    })

    let contactT = xjot.object ({
        firstName : xjot.string( { required: true, maxLength: 18, autoTruncate: true, dbfield: "first_name" }),
        lastName : xjot.string( { required: true, maxLength: 18, autoTruncate: true }),
        age: xjot.int( required: false, min:1, max: 77 ),
        address: addressT
    }, { table: "contacts" })