js-string-validator

JavaScript String validator utility class. Based on the builder pattern, this class will all you to validate the given string for user defined criteria.

Add to your application

Get the package from here

npm i js-string-validator

How to use

• Basic usage

const StringValidator = require('js-string-validator');
  
let validator = new StringValidator('some string');

let isValidString = validator.min(0).max(20).regex(/\s+/).includes('string').validate();

console.log(isValidString);
// true -> string obey all criteria

console.log(validator.validate());
// true -> valid string without any criteria

validator = new StringValidator();

console.log(validator.validate());
// false -> Not a valid string

• Builder

Create a template (validator function) for re-usability

const StringValidatorBuilder = require('js-string-validator/builder');
  
const validator = StringValidatorBuilder().min(0).max(20).regex(/\s+/).includes('string').build();

console.log(validator('some string'));
// true  -> string obeys the pattern

console.log(validator('random'));
// false -> string violates the pattern

console.log(validator());
// false -> undefined not allowed

API specification

• Basic usage

Following methods can be linked to validate a given string

Method	Definition	Usage	Example
constructor	new StringValidator(value) ; value: string | null | undefined	Initialize the validator with value to be validated.	new StringValidator()
length	length(number) ; number : any	Validate the length of the string. Validation is skipped if number not 0 or +.	validator.length(1).validate()
max	max(number) ; number : any	Validate the max length of the string. Validation is skipped if number is not 0 or +.	validator.max(10).validate()
min	min(number) ; number : any	Validate the min length of the string. Validation is skipped if number is not 0 or +.	validator.min(0).validate()
regex	regex(regexPattern) ; regexPattern : any	Validate for the string for given regexPattern. Validation is skipped if the pattern is not a regex	validator.regex(/[0-9a-zA-Z]+/).validate()
includes	includes(subString) ; subString: any	Validate if subString includes in the string. Validation is skipped if the subString is undefined	validator.includes('test').validate()
allow	allow(allowedValue) ; allowedValue: any	Validate true if constructed with allowedValue	validator.allow(undefined).validate()
validate	validate()	Validate the given string with given criteria	validator.max(10).min(0).validate()

• Builder

Builder API will allow creation of a template for String validation.

length, max, regex, includes, allow can be used to build a template (combine these methods in any form suits).

Use build() to generate a validator function.

StringValidatorBuilder().length(number).max(number).min(number).regex(regexPattern).includes(subString).allow(allowedValue).build();