Validate

The Validate node checks input fields against a list of validation rules. If any rule fails, it returns an error object with _valid: false and a list of error messages. If all rules pass, the input flows through unchanged.

Configuration

Property	Type	Default	Description
rules	array	[]	Required. An array of validation rule objects.

Each rule object has:

Property	Type	Description
field	string	The field name to validate.
rule	string	The validation rule type.
value	string	The rule parameter (used by some rule types).

Validation Rule Types

Rule	Value	Description
required	--	Field must not be null, empty string, or empty array.
min_length	number	String must be at least this many characters.
max_length	number	String must be at most this many characters.
email	--	Must be a valid email address (uses FILTER_VALIDATE_EMAIL).
numeric	--	Must be a numeric value.
min	number	Numeric value must be at least this amount.
max	number	Numeric value must be at most this amount.
regex	pattern	Must match the given regular expression pattern (without delimiters).

Input

Accepts a single object or an array of rows. When an array is provided, only the first row is validated.

Output

Validation passes

Returns the input data unchanged.

Validation fails

Returns an error object:

{
  "_valid": false,
  "_errors": [
    { "field": "email", "message": "email must be a valid email" },
    { "field": "name", "message": "name is required" }
  ]
}

The frontend form system automatically displays these errors next to the corresponding form fields.

Example Rule Configurations

Contact form validation

[
  { "field": "name", "rule": "required" },
  { "field": "name", "rule": "min_length", "value": "2" },
  { "field": "email", "rule": "required" },
  { "field": "email", "rule": "email" },
  { "field": "message", "rule": "required" },
  { "field": "message", "rule": "min_length", "value": "10" }
]

Numeric range validation

[
  { "field": "quantity", "rule": "required" },
  { "field": "quantity", "rule": "numeric" },
  { "field": "quantity", "rule": "min", "value": "1" },
  { "field": "quantity", "rule": "max", "value": "100" }
]

Pattern-based validation

[
  { "field": "phone", "rule": "regex", "value": "^\\+?[0-9\\s\\-]{7,15}$" },
  { "field": "username", "rule": "regex", "value": "^[a-zA-Z0-9_]{3,20}$" }
]

Example Use Case

Form submission pipeline

Context --> Validate --> Sanitize --> Save Row --> Send Email --> Output

If validation fails, the pipeline returns the _valid: false response immediately. The form displays errors, and no data is saved or emailed.

TIP

Always pair Validate with Sanitize in form submission pipelines. Validate checks correctness; Sanitize cleans the data before storage.

WARNING

Validation runs server-side and cannot be bypassed by manipulating the frontend. This is a security feature -- always validate user input in the pipeline, even if you also validate on the client.