CODEWITHSUNDEEP
vim
mhitza
mhitza

Reputation: 5715

Trigger command on buffer load and buffer save

I want to write a vim plugin that does certain text transformations to the text while in the editor, but I don't want these transformations visible inside the file.

As an example, consider the word Gnarly in a text file I want to edit. Upon load I would want my vim script change that to G, but when I save the buffer I want it to expanded back to Gnarly.

My scenario is a little bit more complex because it will involve an external script, but I want to see exactly how that would be invoked.

Also I'd want to be able to apply this change only to some files based on their extension.

Upvotes: 1

Views: 353

Answers (2)

Ingo Karkat
Ingo Karkat

Reputation: 172758

First of all, define your own filetype, e.g. gnarly. Read :help new-filetype for the details, but basically it's this autocmd:

:autocmd BufRead,BufNewFile *.gnarly        set filetype=gnarly

Then, the conceal feature introduced in Vim 7.3 is the way to go. Write a syntax script ~/.vim/syntax/gnarly.vim. For your example it would contain:

:syntax keyword gnarlyConceal Gnarly conceal cchar=G

But you can also use :syntax match for more complex patterns.

Finally, concealment is off by default. To turn it on, put the following command into ~/.vim/ftplugin/gnarly.vim (you could put it into the syntax file, too, but this separation is recommended and done by all full plugins that ship with Vim):

:setlocal conceallevel=1

You can customize the 'concealcursor' behavior, too. If you still need help, have a look at the help pages, or existing plugins that use concealment.

Upvotes: 2

romainl
romainl

Reputation: 196886

See :h autocmd. The events you need are BufRead and BufWrite.

Maybe you will be interested by :h conceal.

Upvotes: 3

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