Regex Decorator ​

The Regex decorator allows for the validation of string properties against a specified regular expression pattern. This ensures that the property value conforms to a specific format, making it incredibly useful for validating emails, phone numbers, URLs, and more.

Properties ​

• pattern: RegExp - The regular expression pattern the string must match.
• flags: string - Optional flags to apply to the pattern, such as 'i' for case-insensitive matching.
• message: string - A custom error message to return if the validation fails.
• invertMatch: boolean - If set to true, the validation succeeds only if the string does NOT match the pattern.
• testAgainstTrimmedValue: boolean - Determines whether to test the trimmed value of the string.
• allowEmptyString: boolean - Determines whether an empty string should be considered a valid value.

Usage ​

To use the RegexValidator, apply it to any string property in your class that needs to match a specific pattern.

Example ​

import { ClassValidator, Regex } from "rest-data-validator";

@ClassValidator
class User {
  @Regex({
    pattern: /^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$/,
    message: "Invalid email format",
  })
  email: string;
}

In this example, the email property must match the specified pattern, ensuring it follows a valid email format.

Inverting Match ​

@Regex({ pattern: /example/, invertMatch: true, message: 'Value must not contain "example"' })
value: string;

This configuration ensures that the validation passes only if the string does not contain the word "example".

Testing Against Trimmed Value ​

@Regex({ pattern: /^\d+$/, testAgainstTrimmedValue: true })
value: string;

This ensures that the string, when trimmed, consists only of digits, making it suitable for numeric IDs or codes that might have accidental whitespace.