Data validations

Data validation allows you to define rules for your fields, including acceptable value ranges.

Validation Properties

Use the .validate() method to add validation rules to a field. The method accepts validation rules as arguments, where each rule can be either:

• A validation function that returns true for valid values
• A tuple of [validationFunction, errorMessage] for custom error messages

db.string().validate(
  ({ value }) => value.includes("@"), // validation function
  [({ value }) => value.length > 5, "Must be longer than 5 characters"], // with error message
);

The validation function receives an object with:

• value: The current field value
• data: The entire record data
• user: The user context performing the operation

Notes:

• The validation rules are evaluated in order
• Validation cannot access fields provided through relation associations

If validate field is set in schema, validation rules will be applied to the field value. The data type of the field is an array of maps, with expr and action defined. The action will be evaluated when the expr returns true.

Property	Type	Scripting Language	Description
script	string	JavaScript	The JavaScript code to evaluate for validation
action	string	-	allow or deny
error_message	string	-	A string of error message to be returned when the validation fails

Notes:

• The validation rules are evaluated in descending order
• expr cannot access the fields provided through sourceId association

If Validate field is set in schema, validation rules will be applied to the field value. The data type of the field is an array of maps, with Expr and Action defined. The Action will be evaluated when the Expr returns true.

Property	Type	Scripting Language	Description
Script.Expr	string	JavaScript	An expression in JavaScript
Action	string	-	tailordb.#Permit.Allow or tailordb.#Permit.Deny
ErrorMessage	string	-	A string of error message to be returned when the validation fails

Notes:

• The validation rules are evaluated in descending order
• Expr cannot access the fields provided through SourceId association

Examples

// reportNumber value must be less than 100 or over 103
reportNumber: db.int().validate([
  ({ value }) => value < 100 || value > 103,
  "reportNumber value must be less than 100 or over 103",
]);

// Description length should be less than 40 characters
description: db.string()
  .description("Description of the product.")
  .validate([
    ({ value }) => value.length < 40,
    "Description length should be less than 40 characters.",
  ]);

// User must be logged in to create an item
itemStatus: db.string().validate([
  ({ user }) => Object.keys(user).length > 0,
  "You must be logged in to create an item",
]);

  reportNumber  = {
    type          = "integer"
    validate      = [
      // reportNumber value must be less than 100 or over 103
      {
        script        = "((value, data) => { return value >=100 && value <=103})(_value, _data)"
        action        = "deny"
        error_message = "reportNumber value must be less than 100 or over 103"
      }
    ]
  }

description = {
  type        = "string"
  description = "Description of the product."
  validate    = [{
    script        = "((value, data) => { return !(value.length < 40)})(_value, _data)"
    action        = "deny"
    error_message = "Description length should be less than 40 characters."
  }]
}

itemStatus = {
  type     = "string"
  validate = [{
    script        = "((value, data) => { return Object.keys(user).length === 0 })(_value, _data)"
    action        = "deny"
    error_message =  "You must be logged in to create an item"
  }]
}

  reportNumber: {
    Type:        tailordb.#TypeInt
    Validate: [
      // reportNumber value must be less than 100 or over 103
      {
        Script: common.#Script & {
          Expr: """
            ((value, data) => {
              return value >=100 && value <=103
            })(_value, _data)
          """
        }
        Action: tailordb.#Permit.Deny
        ErrorMessage: "reportNumber value must be less than 100 or over 103"
      }
    ]
  }

description: {
  Type:        tailordb.#TypeString
  Description: "Description of the product."
  Validate: [{
    Script: common.#Script & {
      Expr: """
        ((value, data) => {
          return !(value.length < 40)
        })(_value, _data)
      """
    }
    Action: tailordb.#Permit.Deny
    ErrorMessage: "Description length should be less than 40 characters."
  }]
}

itemStatus: {
  Type: tailordb.#TypeString
  Validate: [{
    Script: common.#Script & {
      Expr: """
        ((value, data) => {
          return Object.keys(user).length === 0
        })(_value, _data)
        """
      }
    Action:       tailordb.#Permit.Deny
    ErrorMessage: "You must be logged in to create an item"
  }]
}

Example demonstrating how to use user attributes

itemCode: db.string().validate([
  ({ user }) => user.attributes.includes("{ADMIN_ID}"),
  "To create an item, you must be the Admin",
]);

  itemCode = {
    type     = "string"
    validate = [{
      script        = "((value, data) => { return !user.attributes.includes(\"{ADMIN_ID}\") })(_value, _data)"
      action        = "deny"
      error_message =  "To create an item, you must be the Admin"
    }]
  }

  itemCode: {
    Type: tailordb.#TypeString
    Validate: [
      {
        Script: common.#Script & {
          Expr: """
            ((value, data) => {
              return !user.attributes.includes(\"{ADMIN_ID}\")
            })(_value, _data)
          """
        }
        Action:       tailordb.#Permit.Deny
        ErrorMessage: "To create an item, you must be the Admin"
      }
    ]
  }

Accessible variables in expressions

You can use _value to refer to the current field value and _data to refer to the entire record.

Variable	Description
_value	This accesses its own field value.
_data.{other_field_name}	Other fields can be accessed using the field name. ex. foo == 2 accesses foo field
_data.{array_name}[{index}]	This accesses the array value. ex. arr[0] accesses the first value of arr
_data.{associative_array_name}.{key_name}	This accesses associative array value. ex. dict.nestedValue accesses the dict associative array's nestedValue key value
user	This accesses the user context. ex. user.id accesses the logged in user id and user.attributes acessess user's attributes which is an array of UUIDs that are configured in the AttributesFields in the Auth service