Question

Does anyone know if a user generated HTML5 Canvas could be attached to a Facebook ‘Like’ action and shared on a Facebook wall?

I guess the canvas would have to be rendered to an <img> tag and the id of the tag specified in the og:image metadata?

Answer 1

You have two options as I see it.

(1) Use the Like Button and in it put a dynamic url which generates the og tags for the configuration the user has chosen.
In the 2nd step of the like button tutorial it generates the og tags for you so you can see what’s needed, then just make sure that your server generates those according to what the user configured.
You’ll have to make a request from your page to the server when the user finished his configuration so that this will be possible.

(2) Use the Feed Dialog that comes with the js sdk.
Using that you can specify all of the story fields, for example:

var obj = {
    method: "feed",
    picture: "URL_FOR_THE_CONFIGURED_BIKES_PIC",
    name: "My custom bikes!",
    caption: "I just finished building a new pair of bikes",
    description: "My configuration: ....."
};

FB.ui(obj, function(response) {
    console.log(response);
});

It is of course possible to mix both options into a third, if you have a specific url per configuration then you can simply:

FB.ui({
    method: "feed",
    link: "URL_FOR_THE_USER_CONFIGURATION"
}, function(response) {
    console.log(response);
});

And then facebook will extract the data from the og tags in that link.