[ This description is mirrored from README.md at github.com/Zecat/google-recaptcha on 2019-05-22 ]

<google-recaptcha>

A Polymer element for google recaptcha V2 and invisible.

<dom-bind>
  <template is="dom-bind">
    <google-recaptcha
      force-in-body
      value="{{token}}"
      sitekey="6LdHISEUAAAAAN0FxtC5OBGQv-zrtj1tQ1Z_KUWf"
    ></google-recaptcha>
    <span>[[token]]</span>
  </template>
</dom-bind>

Install

  bower install -S Zecat/google-recaptcha

Notes

• Promise polyfill is a dev dependency.
• Visit https://www.google.com/recaptcha/admin to get a sitekey.

Shadow DOM work-around

By-design, the google recaptcha doesn't work inside shadow dom, so we detect when it has a ShadowRoot parent and if so, the recaptcha is placed in a container light DOM, which sync its size and screen position with its original <google-recaptcha> parent, and the container is moved into the body. The container is refit every time the user scroll or the <google-recaptcha> is notified of resize. This is an expensive task but the only solution so far.