Add xmllint via ale to neovim

Maintain all dependencies via nix / home-manager.
Load xsd schema file.
Define nix xmllint for linting.

home.nix

@@ -146,6 +146,13 @@
     "borg/exclude".source = ./home/files/borg-exclude;
   };
 
+  xdg.dataFile = {
+    "xsd/xliff-core-1.2-strict.xsd".source = pkgs.fetchurl {
+      url = "https://docs.oasis-open.org/xliff/v1.2/os/xliff-core-1.2-strict.xsd";
+      sha256 = "nzevVk7NJ9X2kVTXz+e6jesfYgyBuUzw6rH0IFx01fg=";
+    };
+  };
+
   xdg.desktopEntries = {
     networkmanager-dmenu = {
       type = "Application";

home/programs/neovim.nix

@@ -338,7 +338,12 @@ in {
 
     {
       plugin = ale;
-      config = pkgs.lib.fileContents ./neovim/plugins/ale.vim;
+      config = pkgs.lib.fileContents(./neovim/plugins/ale.vim)
+        # Keep line break as fileContents strips last EOL
+        + ''
+
+          let g:ale_xml_xmllint_executable = '${pkgs.libxml2}/bin/xmllint'
+        '';
     }
 
     {

home/programs/neovim/configuration/after/ftplugin/xml.vim

@@ -5,9 +5,8 @@ syn spell toplevel
 syn region  xmlString contained start=+"+ end=+"+ contains=xmlEntity,@NoSpell display
 syn region  xmlString contained start=+'+ end=+'+ contains=xmlEntity,@NoSpell display
 
-" TODO: Find a way to distribute the files
-" augroup xliff
-"     autocmd!
-"     autocmd BufEnter **/*.xlf :let g:syntastic_xml_xmllint_args = '-schema ~/.dotfiles/xsd/xliff-core-1.2-strict.xsd'
-"     autocmd BufEnter **/*.xlf :let g:ale_xml_xmllint_options = '-schema ~/.dotfiles/xsd/xliff-core-1.2-strict.xsd'
-" augroup END
+augroup xliff
+    autocmd!
+    " xsd is installed via home manager
+    autocmd BufEnter **/*.xlf :let g:ale_xml_xmllint_options = '-schema ~/.local/share/xsd/xliff-core-1.2-strict.xsd'
+augroup END