locatingRules for DocBook on emacs

[jtojnar]

The emacs DocBook config from Nix Pills, which was copied to the wiki match the schema based on elements, not the namespace. That is suspicious, given that we use DocBook 5 which is namespace aware. Should not we use something like this instead:

<locatingRules xmlns="http://thaiopensource.com/ns/locating-rules/1.0">
  <namespace ns="http://docbook.org/ns/docbook" uri="${docbook5}/xml/rng/docbook/docbookxi.rnc"/>
</locatingRules>

cc @grahamc

Edit: We even have this https://nixos.org/nixos/manual/index.html#sec-emacs-docbook-xml in the manual, which looks more correct. Though, it relies on profile paths, which is not a good idea: #24959

[jtojnar]

Here are the related enacs docs: https://www.gnu.org/software/emacs/manual/html_node/nxml-mode/Locating-a-schema.html#Locating-a-schema

The default schemas (including the old docbook 4) are in ${emacs}/share/emacs/26.3/etc/schema/schemas.xml

[jtojnar]

I verified that the following works.

let
 pkgs = import <nixpkgs> {};
 inherit (pkgs) emacsPackages docbook5 writeText;

 schemas = writeText "schemas.xml" ''
   <locatingRules xmlns="http://thaiopensource.com/ns/locating-rules/1.0">
     <namespace ns="http://docbook.org/ns/docbook" uri="${docbook5}/share/xml/docbook-5.0/rng/docbookxi.rnc"/>
   </locatingRules>
 '';

in emacsPackages.emacsWithPackages (epkgs: [
 (emacsPackages.trivialBuild {
   pname = "nix-docbook-mode";
   version = "1970-01-01";
   src = writeText "default.el" ''
     (eval-after-load 'rng-loc
       '(add-to-list 'rng-schema-locating-files "${schemas}"))
     (global-set-key (kbd "<C-return>") 'nxml-complete)
   '';
 })
])

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[jtojnar]

Needs to be fixed.

[stale]

I marked this as stale due to inactivity. → More info