Changing options at runtime has no effect

[tuurep]

In #31 I noticed:

While testing this I noticed that it's not possible to use these to modify the behavior at runtime like:

• I have a viewer open
• I do :let g:vivify_auto_scroll = 0
• Would expect that viewer to stop auto-scrolling, but this didn't work

The settings would be much more useful if they could be used to programmatically change the viewer behavior, in my opinion.

At first I thought it would be easy to change like this:

diff --git a/plugin/vivify.vim b/plugin/vivify.vim
index f9fb6c7..d4e7fac 100644
--- a/plugin/vivify.vim
+++ b/plugin/vivify.vim
@@ -3,9 +3,6 @@ if exists("g:loaded_vivify")
 endif
 let g:loaded_vivify = 1

-let s:vivify_instant_refresh = get(g:, "vivify_instant_refresh", 1)
-let s:vivify_auto_scroll = get(g:, "vivify_auto_scroll", 1)
-
 let s:filetype_match_str = 'markdown'
 if exists("g:vivify_filetypes")
     call add(g:vivify_filetypes, s:filetype_match_str)
@@ -19,14 +16,14 @@ endfunction
 function! s:init()
     augroup vivify_sync
         autocmd!
-        if s:vivify_instant_refresh
+        if get(g:, "vivify_instant_refresh", 1)
             autocmd TextChanged,TextChangedI *
                 \ if s:is_vivify_filetype(&filetype) | call vivify#sync_content() | endif
         else
             autocmd CursorHold,CursorHoldI *
                 \ if s:is_vivify_filetype(&filetype) | call vivify#sync_content() | endif
         endif
-        if s:vivify_auto_scroll
+        if get(g:, "vivify_auto_scroll", 1)
             autocmd CursorMoved,CursorMovedI *
                 \ if s:is_vivify_filetype(&filetype) | call vivify#sync_cursor() | endif
         endif

But surprised to see it didn't work. Maybe it has to do with it being inside an autocmd?

[tuurep]

Right, I see it:

The g:var is not checked inside the autocmd, but the other way around: g:var is checked only once and autocmd set up based on that.

2 options:

1. inside the autocmds, check the option and either sync_... or don't
   • easy to add
2. create some setup where the autocmds are destroyed/created based on the options
   • I think this may fit better because what we're conditionally changing are the autocmd events for the most part
   • could be too complicated

[tuurep]

We considered those options with @jannis-baum, option 1 is the more obvious thing to add since it is dead simple, and for 2 we didn't know how to do it without some hacky business: for some part we'd need an ability to listen to g:var option changes.

Opening a PR for option 1.