Add Nix derivation for KaTeX

One step closer to a fully declarative website build environment.

1 files changed, 50 insertions, 0 deletions

diff --git a/pkgs/KaTeX.nix b/pkgs/KaTeX.nix
new file mode 100644
index 0000000..6565b13
--- /dev/null
+++ b/pkgs/KaTeX.nix
@@ -0,0 +1,50 @@
+{ stdenv, pkgs, ... }:
+
+let
+  katex-src = stdenv.mkDerivation rec {
+    name = "katex-src";
+
+    src = pkgs.fetchzip {
+      url    = "https://github.com/Khan/KaTeX/releases/download/v0.10.0-alpha/katex.zip";
+      sha256 = "002dzyf3wcyjxv4m6vv0v99gf82a9k7rxsnlvf93h9fhcda2vj7l";
+    };
+
+    buildInputs = [ pkgs.nodejs ];
+
+    installPhase = ''
+      mkdir -p $out/share/katex
+
+      cp katex.min.js $out/share/katex/
+    '';
+
+    meta = {
+      description = "KaTeX";
+      homepage    = https://github.com/Khan/KaTeX;
+      license     = stdenv.lib.licenses.mit;
+      platforms   = stdenv.lib.platforms.all;
+    };
+  };
+in pkgs.writeTextFile {
+  name        = "katex-wrapper";
+  executable  = true;
+  destination = "/bin/katex";
+
+  text = ''
+    #!${pkgs.nodejs}/bin/node
+
+    var katex = require("${katex-src}/share/katex/katex.min.js");
+    var input = "";
+
+    var args = process.argv.slice(2);
+
+    process.stdin.on("data", function(chunk) {
+        input += chunk.toString();
+    });
+
+    process.stdin.on("end", function() {
+        var options = { displayMode: args.indexOf("--display-mode") !== -1 };
+        var output = katex.renderToString(input, options);
+        console.log(output);
+    });
+  '';
+}