For LS3, I'm looking to write a reCAPTCHA plugin to replace the LimeSurvey captcha. I was able to accomplish this successfully in 2.06, but it required a ton of core hacking.

My concern with trying to write a plugin for LS3 is that some people have apparently tried already and failed -- due to not being able to validate the reCAPTCHA response.

See: www.limesurvey.org/forum/can-i-do-this-w...283-google-recaptcha

I'd certainly like to tackle the problem, I'm just not sure if it's technically possible at the moment given the plugin hooks. I was hoping a develeoper would be able to provide some feedback, confirm/deny if it's do-able, before I start down that route.

Since we have beforeSurveyPage and beforeControllerAction : you can always reconstruct any page with you own controller

See framagit.org/SondagePro-LimeSurvey-plugi...endAdminStatitistics for an example (for admin part : admin part is more difficult than public (i think).

LS3 have more views (with or without twig) than LS2.05 or even 2.5X. Then in your controller, you can use :
1. Existing controller (extend the default controller)
2. Existing views
3. Replace some views

Then you can surely : update captcha action ( github.com/LimeSurvey/LimeSurvey/blob/ma...eyController.php#L73 ) , and maybe just update the function to call .

BUT : limesurvey is old, and we don't use always YII with a clean class, clean views, and little public function.

Else : maybe : you can extend alias and replace the existing alias for all captcha related part (views and action) ?

I didn't know , but i think it can be done.

I agree we need more modularity for captcha. I don't have time to work on it for now.
At least, you can feel free to make pull request to ls3 so it can handle recaptcha

Hopefully they will make a plug in recaptcha, How the developer here will try to make.