Voucher Code Generator JS

Node.js

Install the package via npm:

$ npm install --save voucher-code-generator

Include it in your project using require:

var voucher_codes = require('voucher-code-generator');

Browser

Include the script directly in your HTML:

<script src="voucher_codes.js"></script>

The pattern option allows you to define a fixed structure for your voucher codes. Use the # symbol to indicate positions where characters from the charset should be inserted.

• The number of # characters in your pattern determines the effective length of the code.
• Characters other than # are treated as literal strings.

Example: A pattern of "XX-####-YY" will result in codes that always start with XX, end with YY, and have 4 variable characters in the middle.

const voucher_codes = require('voucher_codes');

const codes = voucher_codes.generate({
  count: 2,
  pattern: 'PROMO-####'
});
// Example output: ["PROMO-a1b2", "PROMO-c3d4"]

If a configuration is mathematically impossible (e.g., requesting 1000 unique codes that are only 2 characters long using only numbers), the library will throw an error: "Not possible to generate requested number of codes.".

You should wrap your generation logic in a try...catch block to handle these cases.

try {
    voucher_codes.generate({
        count: 1000,
        length: 2,
        charset: "0123456789"
    });
} catch (e) {
    console.log("Sorry, not possible.");
}

Prefix and Postfix

You can surround each generated code with a prefix and/or postfix.

voucher_codes.generate({
    prefix: "promo-",
    postfix: "-2015"
});
// Result: ["promo-WZ4x1t3U-2015"]

Patterns

You can define a specific structure using a pattern. Use the hash symbol (#) as a placeholder for random characters. When a pattern is provided, the length option is ignored.

voucher_codes.generate({
    pattern: "##-###-##",
});
// Result: ["P7-ofW-Ka"]

You can specify a custom string of characters to use for generation, or use one of the library's predefined charsets via voucher_codes.charset(name).

Predefined Charsets

Examples

Custom string charset:

voucher_codes.generate({
    length: 6,
    count: 3,
    charset: "0123456789"
});

Using a predefined charset:

voucher_codes.generate({
    length: 5,
    count: 4,
    charset: voucher_codes.charset("alphabetic")
});

Use the voucher_codes.generate(config, [sequenceOffset]) method to create an array of unique, random codes.

Basic Usage

Generate 5 codes, each 8 characters long:

voucher_codes.generate({
    length: 8,
    count: 5
});

Configuration Options

You can generate a specific code from the pool of all possible combinations by providing a sequenceOffset as the second argument to generate().

• An offset of 0 or less returns the first possible combination.
• An offset greater than or equal to the maximum number of combinations returns the last possible combination.
• When combined with count, you can generate a series of sequential codes starting from that offset.

var sequenceOffset = 52;

voucher_codes.generate({
    count: 3,
    length: 2,
    charset: "0123456789"
}, sequenceOffset);
// Result: ["52", "53", "54"]

The charset(name) function returns a string containing a predefined set of characters. This can be used to populate the charset property in your configuration object.

Supported names:

• numbers: "0123456789"
• alphabetic: "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
• alphanumeric: "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"

const voucher_codes = require('voucher_codes');

const alpha = voucher_codes.charset('alphabetic');
// returns "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"