# Vim live preview (sort of)


When editing Markdown files or internet drafts in
[Pandoc's Markdown](https://tools.ietf.org/html/rfc7328.html), I wanted
to see some live preview window. I looked around a bit, but the solutions presented on the
Internet, seemed to be insufficient, either to clumsy or don't work at all.

My usual routine is: edit -> write -> make -> reload "rendered" file.

Turns out you can automate most of this. Vim has a feature: `--servername <id>` which
allows you to send commands to another vim instance using that `<id>`.
So we need two pieces to make this work.

1. start a vim instance with `--servername markdown` and;
2. some way to send commands to it when building the file, turns out `makeprg` is an
    excellent candidate for this, as I was already using Make.

So to start with (2), add an autocmd:

    autocmd Filetype pandoc set makeprg=makepandoc\ markdown

Which calls this little shell script:

    #!/bin/zsh
    make && \
    vim --servername "${1}" --remote-send '<C-\><C-N>:e<CR>'

And then (1) in a terminal, next to the one you're typing in:

    vim -R --servername markdown draft.txt

Now every time you call `:make` (after writing it), the other vim window reloads it's
file. Some things that obviously don't work: scrollbind, so you need to manual scroll
to the interesting area of your file.

The fancy stuff right now would be to show a screencast, but ... no.