modules/docs: add platformPages option

Author: MattSturgeon

modules/docs/default.nix

@@ -16,6 +16,7 @@ in
     ./menu
     ./option-pages
     ./pages.nix
+    ./platforms.nix
     ./user-guide
   ];
 

modules/docs/option-pages/default.nix

@@ -172,6 +172,9 @@ in
     };
   };
   config.docs = {
+    _utils = {
+      inherit optionsPageModule;
+    };
     # Define pages for each "optionPages" attr
     pages = lib.pipe config.docs.optionPages [
       (lib.filterAttrs (_: v: v.enable))

modules/docs/platforms.nix

@@ -0,0 +1,66 @@
+{
+  lib,
+  config,
+  pkgs,
+  ...
+}:
+let
+  inherit (config.docs._utils)
+    optionsPageModule
+    mkOptionList
+    ;
+
+  evalModule =
+    module:
+    lib.evalModules {
+      modules = [
+        module
+        { _module.check = false; }
+        { _module.args.pkgs = lib.mkForce pkgs; }
+      ];
+    };
+
+  platformPageType = lib.types.submodule (
+    { config, ... }:
+    {
+      imports = [
+        optionsPageModule
+      ];
+      options = {
+        module = lib.mkOption {
+          type = lib.types.deferredModule;
+          description = ''
+            A module defining platform-specific options.
+          '';
+        };
+      };
+      config = {
+        optionsList = lib.pipe config.module [
+          evalModule
+          (lib.getAttr "options")
+          mkOptionList
+        ];
+        page.menu.section = lib.mkDefault "platforms";
+      };
+    }
+  );
+in
+{
+  options.docs = {
+    platformPages = lib.mkOption {
+      type = with lib.types; lazyAttrsOf platformPageType;
+      description = ''
+        A set of platform pages to include in the docs.
+
+        Each enabled platform page will produce a corresponding `pages` page.
+      '';
+      default = { };
+    };
+  };
+
+  # Define pages for each "platformPages" attr
+  config.docs.pages = lib.pipe config.docs.platformPages [
+    (lib.filterAttrs (_: v: v.enable))
+    (builtins.mapAttrs (_: cfg: cfg.page))
+  ];
+}