core/pkgs/build-support/writers/data.nix
2024-05-13 22:24:10 +01:00

81 lines
2.2 KiB
Nix

{ lib, pkgs, formats, runCommand }:
let inherit (lib) last optionalString types;
in {
/* *
Creates a transformer function that writes input data to disk, transformed
by both the `input` and `output` arguments.
# Example
```nix
writeJSON = makeDataWriter { input = builtins.toJSON; output = "cp $inputPath $out"; };
myConfig = writeJSON "config.json" { hello = "world"; }
```
# Type
```
makeDataWriter :: input -> output -> nameOrPath -> data -> (any -> string) -> string -> string -> any -> derivation
input :: T -> string: function that takes the nix data and returns a string
output :: string: script that takes the $inputFile and write the result into $out
nameOrPath :: string: if the name contains a / the files gets written to a sub-folder of $out. The derivation name is the basename of this argument.
data :: T: the data that will be converted.
```
*/
makeDataWriter = lib.warn
"pkgs.writers.makeDataWriter is deprecated. Use pkgs.writeTextFile."
({ input ? lib.id, output ? "cp $inputPath $out" }:
nameOrPath: data:
assert (types.path.check nameOrPath)
|| (builtins.match "([0-9A-Za-z._])[0-9A-Za-z._-]*" nameOrPath != null);
let name = last (builtins.split "/" nameOrPath);
in runCommand name {
input = input data;
passAsFile = [ "input" ];
} ''
${output}
${optionalString (types.path.check nameOrPath) ''
mv $out tmp
mkdir -p $out/$(dirname "${nameOrPath}")
mv tmp $out/${nameOrPath}
''}
'');
inherit (pkgs) writeText;
/* *
Writes the content to a JSON file.
# Example
```nix
writeJSON "data.json" { hello = "world"; }
```
*/
writeJSON = (pkgs.formats.json { }).generate;
/* *
Writes the content to a TOML file.
# Example
```nix
writeTOML "data.toml" { hello = "world"; }
```
*/
writeTOML = (pkgs.formats.toml { }).generate;
/* *
Writes the content to a YAML file.
# Example
```nix
writeYAML "data.yaml" { hello = "world"; }
```
*/
writeYAML = (pkgs.formats.yaml { }).generate;
}