In the last year `programs.oh-my-zsh` gained more complexity and since
the introduction of features like `customPkgs` which builds a
`ZSH_CUSTOM` path from a sequence of derivation a documentation may be
fairly helpful to make the knowledge how to use the module and how to
package new ZSH plugins visible.
See https://github.com/NixOS/nixpkgs/pull/43282#issuecomment-410770432
If multiple third-party modules shall be used for `oh-my-zsh` it has to
be possible to create another env which composes all the packages.
Now it can be done like this:
```
{ pkgs, ... }:
{
programs.zsh.enable = true;
programs.zsh.ohMyZsh = {
enable = true;
customPkgs = with pkgs; [
lambda-mod-zsh-theme
nix-zsh-completions
];
theme = "lambda-mod";
plugins = [ "nix" ];
};
}
```
Please keep in mind that this is not compatible with
`programs.zsh.ohMyZsh.custom`, only one of these options can be used
ATM.
Each package should store its outputs into
`$out/share/zsh/<output-name>`. Completions (and ZSH-only) extensions
should live in the `fpath` (`$out/share/zsh/site-functions`), plugins in
`.../plugins` and themes in `.../themes` (please refer to
fdb6bf6ed68c2f089ae6c729dfeaa3eddea2ce6a and 406d64aad162b3a4881747be4e24705fb5182573).
All scripts in `customPkgs` will be linked together using `linkFarm` to
provide a single directory for all scripts from all derivations in
`customPkgs` as suggested in https://github.com/NixOS/nixpkgs/pull/43282#issuecomment-410396365.
The default cache directory set by oh-my-zsh is $ohMyZsh/cache which
lives in the Nix store in our case. This causes issues with several
completion plugins provided by oh-my-zsh.
Originially, `programs.zsh` sets default values for some
initialisation scripts.
Nix resolves the case of multiple values by concatenating them all.
It is however impossible to predict where the default script will be
inserted; but we never want the default value to override the
user-specified ones.
Now, it doesn't set default values; almost everything is hardcoded at
the begining of the file.
* programs.zsh: add enableOhMyZsh option to automate setup of oh-my-zsh in global zshrc
* programs.zsh: make oh-my-zsh plugins configurable
* programs.zsh: add ohMyZshCustom option
* programs.zsh: add ohMyZshTheme option
* programs.zsh: applying minor fixes to evaluate expressions properly
* programs.zsh: fix ordering of oh-my-zsh config and execution
* programs.zsh: move all oh-my-zsh params into its own scope named programs.zsh.oh-my-zsh
