add programs.niri.extraConfig

README.md

@@ -91,16 +91,25 @@ But you can also pass it a string:
 }
 ```
 
-or set `programs.niri.config = null;` to prevent this module from generating a config file. By default, it will generate a config file based on `programs.niri.settings` if it is not `null`.
+By default its value is derived from `programs.niri.settings`.
 
-For debugging (primarily development of this flake i guess), there is also `programs.niri.finalConfig` which is always a string (or null) and represents the final config file that will be end up in your config directory.
+You can also combine option-based configuration with manual one by
+setting `programs.niri.extraConfig`.  It has the same type as
+`programs.niri.config` and defaults to `null`.
+
+If both `programs.niri.config` and `programs.niri.extraConfig` are
+`null`, this module will not generate a config file at all.
+
+For debugging (primarily development of this flake i guess), there is also `programs.niri.finalConfig` which is always a string (or null) and represents the final rendered config file that will end up in your config directory.
 
 > [!note]
 > `programs.niri.settings` is not guaranteed to be compatible with niri versions other than the two provided by this flake. \
 > In particular, this means that i do not guarantee compatibility with the one from nixpkgs at all times (i.e. when nixpkgs is lagging behind due to build failures or other reasons). \
 > In practice, you will not have an issue with this unless you are running old versions of niri that are 2 or more releases behind. I will try my best not to break compatibility with nixpkgs.
 >
-> This does not apply to `programs.niri.config` as it is inherently version-agnostic and still provides build-time validation.
+> This does not apply to `programs.niri.config` and `programs.niri.extraConfig` as those are inherently version-agnostic.
+>
+> The final config is always validated at build time.
 
 # Stylix
 

settings.nix

@@ -3036,21 +3036,47 @@
 
             - When this is null, no config file is generated.
             - When this is a string, it is assumed to be the config file contents.
-            - When this is kdl document, it is serialized to a string before being used as the config file contents.
+            - When this is a KDL document, it is serialized to a string before being used as the config file contents.
 
-            By default, this is a KDL document that reflects the settings in ${link' "programs.niri.settings"}.
+            By default, this is a KDL document that reflects the settings in ${link' "programs.niri.settings"} plus ${link' "programs.niri.extraConfig"}.
+          '';
+        };
+
+        extraConfig = mkOption {
+          type = types.nullOr (types.either types.str kdl.types.kdl-document);
+          default = null;
+          description = ''
+            A verbatim section to be appended to the niri config file.
+
+            - When this is null, nothing will be appended.
+            - When this is a string, it is assumed to be literal config file contents.
+            - When this is a KDL document, it is serialized to a string before being appended to the config file.
           '';
         };
 
         finalConfig = mkOption {
           type = types.nullOr types.str;
           default =
-            if builtins.isString cfg.config then
-              cfg.config
-            else if cfg.config != null then
-              kdl.serialize.nodes cfg.config
+            let
+              flatten =
+                value:
+                if builtins.isString value then
+                  value
+                else if value != null then
+                  kdl.serialize.nodes value
+                else
+                  null;
+
+              mainRendered = flatten cfg.config;
+              extraRendered = flatten cfg.extraConfig;
+            in
+            if mainRendered == null then
+              extraRendered
+            else if extraRendered == null then
+              mainRendered
             else
-              null;
+              mainRendered + "\n" + extraRendered;
+
           readOnly = true;
           defaultText = null;
           description = ''