Add a newline if the prompt is too long

[Rmano]

Shell: zsh
Operating system: linux Ubuntu 18.04
Liquid Prompt version (tag, commit): 5f4aeec

I am trying to add a newline to the prompt only if the characters left are less than, say, 30. In plain zsh you can use the %-30 prompt directive, so I tried

export LP_PS1_POSTFIX=$'%-30(l:\n> :)'

...but it is doing nothing. Is there a correct way to do this?

Thanks for the nice software!

[Rycieos]

I'm assuming that that type of expansion doesn't work because we set the nopromptsubst option:
https://github.com/nojhan/liquidprompt/blob/af63c4cfb8afe3f3161f3ace4aba3b940847a7a8/liquidprompt#L1942-L1943

You could try enabling it yourself and seeing if it will then expand this option.

I like this idea though, and want to see it added as a feature. This means we couldn't rely on zsh specific things obviously.

[Rmano]

I tried this in my .zshrc:

liquidprompt=$HOME/software/liquidprompt/liquidprompt
[[ -f $liquidprompt ]] && source $liquidprompt
# see https://github.com/nojhan/liquidprompt/issues/599
setopt promptsubst
export LP_PS1_POSTFIX=$'%-30(l:\n> :)'

...but still not working. Well, I'll wait...

[nojhan]

What are your ideas about the following options for generalizing @PandaWill's idea?

1. Allow to automatically switch theme when the current prompt overflows the terminal width. Cons: this would need some specific themes to actually implement the prompt shortening (like a heavily multi-line theme); this allows for only two options. Pros: this is very simple, with the current code; this may be generalized later as an automatic theme switcher ("if this state matches this, switch to this theme").
2. Allow for several, ordered, breakable markers, which would be activated if the prompt overflows. Themes would need to be updated to add markers (I'm thinking something like $LP_BREAK_1, $LP_BREAK_2), which would be replaced either by an empty space or a new line. Pros: this allows for adaptation to any terminal width. Cons: this is more complicated to implement (need to check that themes do not use duplicate breaks, for instance) which may hinder speed.

[Rycieos]

What are your ideas about the following options for generalizing @PandaWill's idea?

I really like your second idea. I have another one:
3. A priority system for each section, where if maximum prompt width and/or lines are reached, lowest priority sections are not displayed. Could be combined with idea 2 to still define where to break.

Unfortunately I think that is beyond the possibility of the Liquid Prompt engine...

I think something like 2 could be possible, if not very complicated...