view mod_ogp/README.markdown @ 4738:5aee8d86629a

mod_bookmarks2: Fix handling of nick and password elements This form of child retrieval fails when the stanza elements internally don't have an 'xmlns' attribute, which can happen sometimes for some reason, including when they have been constructed via the stanza builder API. When that is the case then the explicit namespace arguemnt does not match the nil value of the internal attribute. Calling `:get_child()` without the namespace argument does the right thing here, with both nil and the parent namespace as valid values for the internal attribute.
author Kim Alvefur <zash@zash.se>
date Wed, 03 Nov 2021 21:11:55 +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" }
```