view mod_ogp/README.markdown @ 5119:048e339706ba

mod_rest: Remove manual reference expansion in schema This hack was originally added to reduce the number of definitions of common attributes (type, to, from etc) and payloads (e.g. delay). This predated pointers and references, and until now was needed because parsing picked out the correct stanza kind from the schema, which broke internal references. Removing this hack paves the way for allowing the schema to be configured or customized more easily.
author Kim Alvefur <zash@zash.se>
date Tue, 20 Dec 2022 21:48:28 +0100
parents 09f0911c735d
children
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# mod_ogp

This module adds [Open Graph Protocol](https://ogp.me) metadata to URLs sent inside a MUC.

With mod_ogp enabled, when a user sends a URL in a MUC (where the message has its `id` equal to its `origin-id`), the module calls the URL and parses the result for `<meta>` html tags that have any `og:...` properties.
If it finds any, it sends a [XEP-0422 fastening](https://xmpp.org/extensions/xep-0422.html) applied to the original message that looks like:

```xml
<message id="example" from="chatroom@muc.example.org" to="user@chat.example.org/resource">
<apply-to xmlns="urn:xmpp:fasten:0" id="origin-id-X">
<meta xmlns="http://www.w3.org/1999/xhtml" property="og:title" content="The Rock"/>
<meta xmlns="http://www.w3.org/1999/xhtml" property="og:url" content="https://www.imdb.com/title/tt0117500/"/>
<meta xmlns="http://www.w3.org/1999/xhtml" property="og:image" content="https://ia.media-imdb.com/images/rock.jpg"/>
</apply-to>
</message>
```

The module is intentionally simple in the sense that it is basically a transport for https://ogp.me/

Configuration
-------------

You can present an allowlist or denylist of domains for which OGP metadata will be fetched
via the `ogp_domain_allowlist` and `ogp_domain_denylist` settings repectively.

For example:

```lua
Component "muc.example.org" "muc"
  modules_enabled = { "ogp" }
  ogp_domain_allowlist = { "prosody.im" }
```