ReCaptcha v2 client side events

问题:

Does ReCaptcha v2 expose any client side events? I am looking specifically to identify when the Captcha response has been returned once the box is ticked, so I can reveal the "Continue" button below.

Without this it is possible for the user to click the checkbox then quickly click the submit button before the captcha response is back.

I could possible add my own click event handler to the class recaptcha-checkbox-checkmark and poll the visiblity of the tick, I just wondered if there was a simpler way to do this?

$(".recaptcha-checkbox-checkmark").click(function() {
    //...Poll for visibility of tick
});

回答1:

You can configure reCAPTCHA to give a callback on successful validation using the data-callback attribute on the g-recaptcha tag or via the 'callback' parameter if using explicit rendering.

See https://developers.google.com/recaptcha/docs/display#render_param

Example using explicit rendering:

var myCallback = function(val) { console.log(val); };
grecaptcha.render(
   document.getElementsById('my-recaptcha-placeholder'), 
   {
     callback: myCallback, 
     sitekey: mySiteKey
   });

回答2:

Another solution is to set data-callback directly on the g-recaptcha div, like this

<script type="text/javascript">
  var imNotARobot = function() {
    console.info("Button was clicked");
  };
</script>

<div class="g-recaptcha" data-callback="imNotARobot" data-sitekey="key"></div>