Is there an analogue of mailru.app.events.like for websites?

Question

JavaScript

Social networks are a great marketing tool, but sometimes they don't want to give their features the opportunity to save the user. I have a task before me: there is an online store, there are “like” buttons (quite standard ones, i.e. not in the form of your own bicycle, which asks for permission to add a like on click, but ordinary such buttons). It is necessary to intercept the like and unlike event, namely, on clicking "like" through ajax, load a one-time discount coupon code and show it to the user.
If the store were an application, then everything would be simple - there is a mailru.app.events.like event, but there is no such event for sites. Like/dislike create cookies, but they are for the *.mail.ru domain. The buttons themselves are in an iframe, the content of which cannot be retrieved either.
Perhaps someone faced a similar task - tell me how this can be done and whether it can be implemented.
Moral side of the issue: social networks are NOT against incentivizing clicks on “likes” if everything is fair to the user.

Answer 1

If, for example, using jQuery, then you can do this:

$("iframe").contents().find("#like-button").click(function() {
    //your code    
});

If there is more than one iframe on the page, then the selector obviously needs to be refined.

Answer 2

In my case, there were about a dozen like buttons on the page and it was necessary to understand which one was clicked on. I caught that the widget inserts an iframe with buttons before . They also have click event catchers: http://api.mail.ru/2012/01/share_and_event/ they give result.id and so the iframe on the page is generated with this id. In total, I caught the value I needed like this:
<a target="_blank" class="mrc__plugin_uber_like_button"
data-good-id="МойИтемАйди"
href="http://connect.mail.ru/share?share_url=<?=$urly?>"
data-mrc-config="{'type' : 'small', 'caption-mm' : '2', 'caption-ok' : '1', 'width' : '50px', 'nc' : '1', 'nt' : '1'}">Нравится
mailru.loader.require('api', function(){
mailru.events.listen(mailru.plugin.events.liked, function(result, params, elsevar){
good_id = $("#"+result.id).parent().next().attr("data-good-id");
});
mailru.events.listen(mailru.plugin.events.unliked, function(result){
// console.log(result.type);
// Анлайки всё равно не пашут :)
});
});