Commit 6f695f3d authored by Jan Tojnar's avatar Jan Tojnar
Browse files

makeHardcodeGsettingsPatch: Improve docs 

- Describe arguments and usage in more detail.
- Use finalAttrs in example.
- Use schema id, not path.
- Schema id is not what is replaced.
parent 81283429

pkgs/build-support/make-hardcode-gsettings-patch/default.nix

+31 −15
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@@ -6,12 +6,32 @@ 
}:



/*

  Can be used as part of an update script to automatically create a patch

  hardcoding the path of all GSettings schemas in C code.

  For example:

  Creates a patch that replaces every instantiation of GSettings in a C project

  with a code that loads a GSettings schema from a hardcoded path.



  This is useful so that libraries can find schemas even though Nix lacks

  a standard location like /usr/share, where GSettings system could look for schemas.

  The derivation is is somewhat dependency-heavy so it is best used as part of an update script.



  For each schema id referenced in the source code (e.g. org.gnome.evolution),

  a variable name such as `EVOLUTION` must be provided.

  It will end up in the generated patch as `@EVOLUTION@` placeholder, which should be replaced at build time

  with a path to the directory containing a `gschemas.compiled` file that includes the schema.





  Arguments:

  - `src`: source to generate the patch for.



  - `schemaIdToVariableMapping`: attrset assigning schema ids to variable names.

    All used schemas must be listed.



    For example, `{ "org.gnome.evolution" = "EVOLUTION_SCHEMA_PATH"; }`

    hardcodes looking for `org.gnome.evolution` into `@EVOLUTION_SCHEMA_PATH@`.



  Example:

    passthru = {

      hardcodeGsettingsPatch = makeHardcodeGsettingsPatch {

      inherit src;

        inherit (finalAttrs) src;

        schemaIdToVariableMapping = {

           ...

        };
@@ -28,10 +48,6 @@ 
      ];

      };

    }

  takes as input a mapping from schema path to variable name.

  For example `{ "org.gnome.evolution" = "EVOLUTION_SCHEMA_PATH"; }`

  hardcodes looking for `org.gnome.evolution` into `@EVOLUTION_SCHEMA_PATH@`.

  All schemas must be listed.

*/

{

  src,

pkgs/build-support/make-hardcode-gsettings-patch/hardcode-gsettings.cocci

+9 −6
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/**

 * Since Nix does not have a standard location like /usr/share,

 * where GSettings system could look for schemas, we need to point the software to a correct location somehow.

 * Since Nix does not have a standard location like /usr/share where GSettings system

 * could look for schemas, we need to point the software to a correct location somehow.

 * For executables, we handle this using wrappers but this is not an option for libraries like e-d-s.

 * Instead, we hardcode the schema path when creating the settings.

 * A schema path (ie org.gnome.evolution) can be replaced by @EVOLUTION_SCHEMA_ID@

 * which is then replaced at build time by substituteAll.

 * The mapping is provided in a json file ./glib-schema-to-var.json

 * Instead, we patch the source code to look for the schema in a schema source

 * through a hardcoded path to the schema.

 *

 * For each schema id referenced in the source code (e.g. org.gnome.evolution),

 * a variable name such as `EVOLUTION` must be provided in the ./glib-schema-to-var.json JSON file.

 * It will end up in the resulting patch as `@EVOLUTION@` placeholder, which should be replaced at build time

 * with a path to the directory containing a `gschemas.compiled` file that includes the schema.

 */



@initialize:python@