Discourse automatically converts recognized urls to onebox post inserts.
Right now a common thing we might expect is linking to posts on the old forum. However, currently the every linked forum post returns a generic onebox – not with the title of the post, but with the forum title.
So, for example, here are two links to posts: “List-based interpolations” and “PIxel test for simple sketches.”
We might consider adding a custom onebox config for forum.processing.org, if that is easy enough to do.
If it helps, the way you do this is by adding <meta> tags to the top of each HTML page:
<meta property="og:url" content="page_url_here" />
<meta property="og:site_name" content="Processing Forum" />
<meta property="og:image" content="img_url_here" />
<meta property="og:title" content="page_title_here" />
<meta property="og:description" content="page_description_here" />
I don’t know if Vanilla allows you to add custom HTML to each page or to get these properties from the thread pages, but if you can get that stuff then the rest is pretty easy.