Add support for --input arguments

Author: jbgi

default.nix

@@ -23,6 +23,7 @@ in
       "extraPackages"
       "fonts"
       "typstEnv"
+      "inputs"
     ];
 
     # All the drv args
@@ -37,6 +38,7 @@ in
         typstEnv ? (_: [ ]),
         extraPackages ? { },
         file ? "main.typ",
+        inputs ? { },
         format ? "pdf",
         ...
       }@args:
@@ -110,6 +112,10 @@ in
 
             typst c ${file} ${lib.optionalString verbose "--verbose"} ${
               lib.optionalString (format == "html") "--features html"
+            } ${
+              lib.concatStringsSep " " (
+                lib.mapAttrsToList (name: value: "--input ${name}=${lib.escapeShellArg value}") inputs
+              )
             } -f ${format} $out
 
             runHook postBuild

template/flake.nix

@@ -43,6 +43,11 @@
         # This is relative to the directory input above.
         # Default: "main.typ"
         file = "main.typ";
+        # [Optional] Key-value attribute set passed as --input arguments to typst
+        # (available as the `sys.inputs` dictionary)
+        inputs = {
+          "language" = "fr";
+        };
         # [Optional] Typst universe package selection
         #
         # Pass in a function that accept an attrset of Typst pacakges,

tests/default.nix

@@ -95,4 +95,13 @@ in
       local = [ note-meGh ];
     };
   };
+
+  inputs = mkTest {
+    name = "inputs";
+    inputs = {
+      language = "en";
+      name = "John Doe";
+    };
+  };
+
 }

tests/documents/inputs.typ

@@ -0,0 +1,5 @@
+Value of "sys.inputs.language" is #sys.inputs.language
+
+#if sys.inputs.name != "John Doe" {
+  panic("Expected 'John Doe' in 'sys.inputs.name' but got " + sys.inputs.flag)
+}