string_validator 1.1.0

Dart library for validating and sanitizing strings, especially those from user input.

string_validator

=============

String validation and sanitization for Dart.

This is a new fork of validator.dart, which was originally a port of validator.js.

Validators

• equals(String str, comparison) - check if the string matches the comparison.
• contains(String str, seed) - check if the string contains the seed.
• matches(String str, pattern) - check if string matches the pattern. matches('foobar', 'foo').
• isEmail(String str) - check if the string is an email.
• isURL(String str [, options]) - check if the string is an URL. options is an object which defaults to { protocols: ['http','https','ftp'], require_tld: true, require_protocol: false, allow_underscores: false }.
• isFQDN(String str [, options]) - check if the string is a fully qualified domain name (e.g. domain.com). options is an object which defaults to { require_tld: true, allow_underscores: false }.
• isIP(String str [, version]) - check if the string is an IP (version 4 or 6).
• isAlpha(String str) - check if the string contains only letters (a-zA-Z).
• isNumeric(String str) - check if the string contains only numbers.
• isAlphanumeric(String str) - check if the string contains only letters and numbers.
• isBase64(String str) - check if a string is base64 encoded.
• isHexadecimal(String str) - check if the string is a hexadecimal number.
• isHexColor(String str) - check if the string is a hexadecimal color.
• isLowercase(String str) - check if the string is lowercase.
• isUppercase(String str) - check if the string is uppercase.
• isInt(String str) - check if the string is an integer.
• isFloat(String str) - check if the string is a float.
• isDivisibleBy(String str, number) - check if the string is a number that's divisible by another.
• isLength(String str, min [, max]) - check if the string's length falls in a range. Note: this function takes into account surrogate pairs.
• isByteLength(String str, min [, max]) - check if the string's length (in bytes) falls in a range.
• isUUID(String str [, version]) - check if the string is a UUID (version 3, 4 or 5).
• isDate(String str) - check if the string is a date.
• isAfter(String str [, date]) - check if the string is a date that's after the specified date (defaults to now).
• isBefore(String str [, date]) - check if the string is a date that's before the specified date.
• isIn(String str, values) - check if the string is in a array of allowed values.
• isCreditCard(String str) - check if the string is a credit card.
• isISBN(String str [, version]) - check if the string is an ISBN (version 10 or 13).
• isJSON(String str) - check if the string is valid JSON (note: uses JSON.parse).
• isMultibyte(String str) - check if the string contains one or more multibyte chars.
• isAscii(String str) - check if the string contains ASCII chars only.
• isFullWidth(String str) - check if the string contains any full-width chars.
• isHalfWidth(String str) - check if the string contains any half-width chars.
• isVariableWidth(String str) - check if the string contains a mixture of full and half-width chars.
• isSurrogatePair(String str) - check if the string contains any surrogate pairs chars.
• isMongoId(String str) - check if the string is a valid hex-encoded representation of a [MongoDB ObjectId][mongoid].

Sanitizers

• toString(String input) - convert the input to a string.
• toDate(String input) - convert the input to a date, or null if the input is not a date.
• toFloat(String input) - convert the input to a float, or NaN if the input is not a float.
• toInt(String input [, radix]) - convert the input to an integer, or NaN if the input is not an integer.
• toBoolean(String input [, strict]) - convert the input to a boolean. Everything except for '0', 'false' and '' returns true. In strict mode only '1' and 'true' return true.
• trim(String input [, chars]) - trim characters (whitespace by default) from both sides of the input.
• ltrim(String input [, chars]) - trim characters from the left-side of the input.
• rtrim(String input [, chars]) - trim characters from the right-side of the input.
• escape(String input) - replace <, >, &, ' and " with HTML entities.
• stripLow(String input [, keep_new_lines]) - remove characters with a numerical value < 32 and 127, mostly control characters. If keep_new_lines is true, newline characters are preserved (\n and \r, hex 0xA and 0xD). Unicode-safe in JavaScript.
• whitelist(String input, chars) - remove characters that do not appear in the whitelist. The characters are used in a RegExp and so you will need to escape some chars, e.g. whitelist(String input, '\[\]').
• blacklist(String input, chars) - remove characters that appear in the blacklist. The characters are used in a RegExp and so you will need to escape some chars, e.g. blacklist(String input, '\[\]').
• normalizeEmail(String email [, options]) - canonicalize an email address. options is an object which defaults to { lowercase: true }. With lowercase set to true, the local part of the email address is lowercased for all domains; the hostname is always lowercased and the local part of the email address is always lowercased for hosts that are known to be case-insensitive (currently only GMail). Normalization follows special rules for known providers: currently, GMail addresses have dots removed in the local part and are stripped of tags (e.g. [e-mail] becomes [e-mail]) and all @googlemail.com addresses are normalized to @gmail.com.

Extension Methods

To make using these validators and sanitizers more convenient, this package includes extension methods for each function. These methods can be called directly on a string instance, making the code more concise and readable.

Example Usage

Here are some examples of how to use the extension methods:

import 'package:string_validator/string_validator.dart';

void main() {
  // Using Validator Extensions
  String email = '[e-mail]';
  bool isEmailValid = email.isEmail;

  String url = 'https://example.com';
  bool isUrlValid = url.isURL();

  String ip = '192.168.0.1';
  bool isIpValid = ip.isIP();

  String alpha = 'abc';
  bool isAlphaValid = alpha.isAlpha;

  String numeric = '123';
  bool isNumericValid = numeric.isNumeric;

  String alphanumeric = 'abc123';
  bool isAlphanumericValid = alphanumeric.isAlphanumeric;

  String base64 = 'aGVsbG8gd29ybGQ=';
  bool isBase64Valid = base64.isBase64;

  String integer = '12345';
  bool isIntValid = integer.isInt;

  String float = '123.45';
  bool isFloatValid = float.isFloat;

  String hex = '1f';
  bool isHexValid = hex.isHexadecimal;

  String hexColor = '#ff0000';
  bool isHexColorValid = hexColor.isHexColor;

  String lower = 'hello';
  bool isLowerValid = lower.isLowercase;

  String upper = 'HELLO';
  bool isUpperValid = upper.isUppercase;

  String divisible = '10';
  bool isDivisibleValid = divisible.isDivisibleBy(2);

  String length = 'hello';
  bool isLengthValid = length.isLength(3, 6);

  String byteLength = 'hello';
  bool isByteLengthValid = byteLength.isByteLength(3, 10);

  String uuid = '550e8400-e29b-41d4-a716-446655440000';
  bool isUuidValid = uuid.isUUID();

  String date = '2023-05-17';
  bool isDateValid = date.isDate;

  String afterDate = '2024-01-01';
  bool isAfterValid = afterDate.isAfter('2023-12-31');

  String beforeDate = '2023-01-01';
  bool isBeforeValid = beforeDate.isBefore('2024-01-01');

  String inList = 'apple';
  bool isInValid = inList.isIn(['apple', 'banana', 'cherry']);

  String creditCard = '4111111111111111';
  bool isCreditCardValid = creditCard.isCreditCard;

  String isbn = '978-3-16-148410-0';
  bool isIsbnValid = isbn.isISBN();

  String json = '{"name": "John"}';
  bool isJsonValid = json.isJson;

  String multibyte = '你好';
  bool isMultibyteValid = multibyte.isMultibyte;

  String ascii = 'Hello';
  bool isAsciiValid = ascii.isAscii;

  String fullWidth = 'Ｈｅｌｌｏ';
  bool isFullWidthValid = fullWidth.isFullWidth;

  String halfWidth = 'Hello';
  bool isHalfWidthValid = halfWidth.isHalfWidth;

  String variableWidth = 'Ｈｅllo';
  bool isVariableWidthValid = variableWidth.isVariableWidth;

  String surrogatePair = '𐍈';
  bool isSurrogatePairValid = surrogatePair.isSurrogatePair;

  String mongoId = '507f1f77bcf86cd799439011';
  bool isMongoIdValid = mongoId.isMongoId;

  // Using Sanitizer Extensions
  String dateStr = '2024-05-18';
  DateTime? parsedDate = dateStr.toDate();

  String floatStr = '123.45';
  double parsedFloat = floatStr.toFloat();

  String intStr = '123';
  int parsedInt = intStr.toInt();

  String boolStr = 'true';
  bool parsedBool = boolStr.toBoolean();

  String trimStr = '  hello world  ';
  String trimmedStr = trimStr.trim();

  String ltrimStr = '  hello';
  String ltrimmedStr = ltrimStr.ltrim();

  String rtrimStr = 'hello  ';
  String rtrimmedStr = rtrimStr.rtrim();

  String whitelistStr = 'abcdef';
  String whitelistedStr = whitelistStr.whitelist('abc');

  String blacklistStr = 'abcdef';
  String blacklistedStr = blacklistStr.blacklist('abc');

  String stripLowStr = 'hello\u0000world';
  String strippedLowStr = stripLowStr.stripLow();

  String escapeStr = '<div>"Hello"&</div>';
  String escapedStr = escapeStr.escape();

  String normalizeEmailStr = '[e-mail]';
  String normalizedEmail = normalizeEmailStr.normalizeEmail();
}