How to add git vcs_info to the prompt_bart_setup theme in zsh?

Question

I'm trying to modify the bart theme so it includes git status information. I got it to work, but it doesn't update when I change directories

I modified the bart theme by enabling vcs_info:

prompt_bart_setup () {
    # ...
    autoload -Uz vcs_info
    # Set vcs_info parameters.
    zstyle ':vcs_info:*' enable bzr git hg svn
    zstyle ':vcs_info:*' check-for-changes true
    zstyle ':vcs_info:*' stagedstr '%F{green}●%f'
    zstyle ':vcs_info:*' unstagedstr '%F{yellow}●%f'
    zstyle ':vcs_info:*' formats ' - [%b%c%u]'
    zstyle ':vcs_info:*' actionformats " - [%b%c%u|%F{cyan}%a%f]"
    zstyle ':vcs_info:(sv[nk]|bzr):*' branchformat '%b|%F{cyan}%r%f'
    zstyle ':vcs_info:git*+set-message:*' hooks git-status
    # ...
}

prompt_bart_precmd () {
    # ...
    vcs_info
    # ...
}

And populating the RPROMT variable (it also works with PS1, but I wanted to isolate the problem):

prompt_bart_ps1 () {
    # ...
    RPROMPT="${vcs_info_msg_0_}"
    # ...
}

This works if I create a new terminal session in a git repo, but it doesn't update when I change directories.

I've seen suggestions to use single quotes, but when I change it to this:

prompt_bart_ps1 () {
    # ...
    setopt promptsubst
    RPROMPT='${vcs_info_msg_0_}'
    # ...
}

The prompt shows literally ${vcs_info_msg_0_}. Any ideas?

Answer 1

There seems to be a problem with promptsubst. RPROMPT="${vcs_info_msg_0_}" will substitute the value of vcs_info_msg_0_ when RPROMPT is first defined. That is the reason why it works when you open a shell in a repository but not when you change into one.

The single-quoted variant prevents this initial substitution and setopt promptsubst should then do the substitution everytime the prompt is used. But in your case it doesn't, obviously. Possibly, there is a setopt nopromptsubst somewhere in your zsh configuration that gets called after the one in prompt_bart_setup.

See with setopt | grep promptsubst if it is really set.