# HG changeset patch
# User Matthew Wild <mwild1@gmail.com>
# Date 1708728425 0
# Node ID ed82916e57966288d23d89b070b3056447111c7d
# Parent  904b226fddf1d651cab45889f4c31e2210657d23
mod_server_info: Rewrite/backport from Prosody 1ce18cb3e6cc

diff -r 904b226fddf1 -r ed82916e5796 mod_server_info/README.md
--- a/mod_server_info/README.md	Fri Feb 23 13:02:33 2024 +0000
+++ b/mod_server_info/README.md	Fri Feb 23 22:47:05 2024 +0000
@@ -14,37 +14,52 @@
 
 Everything configured here is publicly visible to other XMPP entities.
 
+**Note:** This module was rewritten in February 2024, the configuration is not
+compatible with the previous version of the module.
+
 ## Configuration
 
-The `server_info` option accepts a list of dataforms. A dataform is an array
-of fields. A field has three required properties:
+The `server_info_extensions` option accepts a list of custom fields to include
+in the server info form.
+
+A field has three required properties:
 
 - `type` - usually `text-single` or `list-multi`
-- `var` - the field name
+- `var` - the field name (see below)
 - `value` the field value
 
 Example configuration:
 
 ``` lua
 server_info = {
-
-	-- Our custom form
-	{
-		-- Conventionally XMPP dataforms have a 'FORM_TYPE' field to
-		-- indicate what type of form it is
-		{ type = "hidden", var = "FORM_TYPE", value = "urn:example:foo" };
+	-- Advertise that our maximum speed is 88 mph
+	{ type = "text-single", var = "speed", value = "88" };
 
-		-- Advertise that our maximum speed is 88 mph
-		{ type = "text-single", var = "speed", value = "88" };
-
-		-- Advertise that the time is 1:20 AM and zero seconds
-		{ type = "text-single", var = "time", value = "01:21:00" };
-	};
-
+	-- Advertise that the time is 1:20 AM and zero seconds
+	{ type = "text-single", var = "time", value = "01:21:00" };
 }
 ```
 
+The `var` attribute is used to uniquely identify fields. Every `var` should be
+registered with the XSF [form registry](https://xmpp.org/registrar/formtypes.html#http:--jabber.org-network-serverinfo),
+or prefixed with a custom namespace using Clark notation, e.g. `{https://example.com}my-field-name`. This is to prevent
+collisions.
+
+## Developers
+
+Developers of other modules can add fields to the form at runtime:
+
+```lua
+module:depends("server_info");
+
+module:add_item("server-info-fields", {
+	{ type = "text-single", var = "speed", value = "88" };
+	{ type = "text-single", var = "time", value = "01:21:00" };
+});
+```
+
+Prosody will ensure they are removed if your module is unloaded.
+
 ## Compatibility
 
-This module should be compatible with Prosody 0.12, and possibly earlier
-versions.
+This module should be compatible with Prosody 0.12 and later.
diff -r 904b226fddf1 -r ed82916e5796 mod_server_info/mod_server_info.lua
--- a/mod_server_info/mod_server_info.lua	Fri Feb 23 13:02:33 2024 +0000
+++ b/mod_server_info/mod_server_info.lua	Fri Feb 23 22:47:05 2024 +0000
@@ -1,18 +1,60 @@
--- XEP-0128: Service Discovery Extensions (manual config)
---
--- Copyright (C) 2023 Matthew Wild
---
--- This project is MIT/X11 licensed. Please see the
--- COPYING file in the source package for more information.
---
+-- mod_server_info imported from Prosody commit 1ce18cb3e6cc for the benefit
+-- of 0.12 deployments. This community version of the module will not load in
+-- newer Prosody versions, which include their own copy of the module.
+--% conflicts: mod_server_info
+
+local dataforms = require "prosody.util.dataforms";
+
+local server_info_config = module:get_option("server_info", {});
+local server_info_custom_fields = module:get_option_array("server_info_extensions");
 
-local dataforms = require "util.dataforms";
-
-local config = module:get_option("server_info");
+-- Source: http://xmpp.org/registrar/formtypes.html#http:--jabber.org-network-serverinfo
+local form_layout = dataforms.new({
+	{ var = "FORM_TYPE"; type = "hidden"; value = "http://jabber.org/network/serverinfo" };
+});
 
-if not config or next(config) == nil then return; end -- Nothing to do
-
-for _, form in ipairs(config) do
-	module:add_extension(dataforms.new(form):form({}, "result"));
+if server_info_custom_fields then
+	for _, field in ipairs(server_info_custom_fields) do
+		table.insert(form_layout, field);
+	end
 end
 
+local generated_form;
+
+function update_form()
+	local new_form = form_layout:form(server_info_config, "result");
+	if generated_form then
+		module:remove_item("extension", generated_form);
+	end
+	generated_form = new_form;
+	module:add_item("extension", generated_form);
+end
+
+function add_fields(event)
+	local fields = event.item;
+	for _, field in ipairs(fields) do
+		table.insert(form_layout, field);
+	end
+	update_form();
+end
+
+function remove_fields(event)
+	local removed_fields = event.item;
+	for _, removed_field in ipairs(removed_fields) do
+		local removed_var = removed_field.var or removed_field.name;
+		for i, field in ipairs(form_layout) do
+			local var = field.var or field.name
+			if var == removed_var then
+				table.remove(form_layout, i);
+				break;
+			end
+		end
+	end
+	update_form();
+end
+
+module:handle_items("server-info-fields", add_fields, remove_fields);
+
+function module.load()
+	update_form();
+end