captcha

Captcha wrapper for captcha services.

Usage

include captcha.js:

<script src="dist/captcha.js"></script>

use captcha object to create captcha service wrappers like this:

mycaptcha = new captcha({
  init: function() { Promise.resolve('...'); },
  get: function(opt) { Promise.resolve('...'); }
  isVerifyFailed: function(err) { ... }
  alt: { ... },
  config: { ... }
  lc: { ... }
});

with following options:

• init(): function for initializing your captcha.

  • will be called only once and always called automatically when get is called.
  • should return Promise.

• get(opt): function used to getting captcha token for verifying through backend.

  • should return Promise resolving object with token field ( {token: ... } ).

  • opt is defined by user.

  • if captcha verification failed, reject with an error which can be recognize with isVerifyFailed.

• isVerifyFailed(err): optional function to check if a given error object err is for verification failure.

  • if alt is provided and when execute calls callback function but an error for verification failure is returned by the callback function, then captcha will try again with another captcha object corresponding to alt.
  • check below section for how execute works.

• alt: optional. either an object for captcha constructor options, or a captcha object.

  • if set, alt will be used when veritification failed with the owner captcha object.

• config: default config object for this captcha object.

  • this is designed for providing configuration to user defined get and init functions.

• lc: object storing default value for storing variables defined by get and init functions.

Once constructed, you can get a token by:

mycaptcha.get().then(function(opt) { opt.token; });

Since token usually involves server-side verification, you can use execute for alt captcha

postData = function({ .../* object returned by `get` */... }) {
  /* should return promise */
  Promise.resolve!
    .then -> /* fetch, ajax with the `get` returned object */
};

mycaptcha.execute({ ... /* options to `get` */ ... }, postData).then(function() { ... });

API

• get(opt): get captcha token. should return Promise resolving {token} object.
  • opt: user defined option for using in user defined get function.
• execute(opt, cb): execute cb with get returned object. return promise
  • opt: options passed to get.
  • cb(ret): callback functions with get returned object as option ( ret ).
    • cb should return Promise. If verification failed, cb can optionally rejects with error object recognizable by isVerifyFailed.
• setConfig: update config object.

ReCaptcha

captcha ships with predefined Google Recaptcha wrapper. use it by first including the needed js:

<script src="dist/captcha.js"></script>
<script src="dist/recaptcha.js"></script>

then:

recaptcha.v2.setConfig({sitekey: '....', enabled: ture});
recaptcha.v2.get();

recaptcha.v3.setConfig({sitekey: '....', enabled: ture});
recaptcha.v3.get();

License

MIT