preview.nvim/lua/preview/commands.lua
Barrett Ruth 62961c8541
feat: unified reload field for live-preview (SSE + long-running watch) (#19)
* feat(reload): add SSE live-reload server module

Problem: HTML output from pandoc has no live-reload; the browser must
be refreshed manually after each compile.

Solution: add lua/preview/reload.lua — a minimal SSE-only TCP server.
start() binds 127.0.0.1:5554 and keeps EventSource connections alive;
broadcast() pushes a reload event to all clients; inject() appends an
EventSource script before </body> (or at EOF) on every compile so
pandoc overwrites do not lose the tag.

* refactor(presets): add reload field, remove synctex field

Problem: the synctex field only handled PDF forward search and left
HTML live-preview and typst watch mode unsupported.

Solution: add reload = function(ctx) returning { 'typst', 'watch',
ctx.file } to typst (long-running watch mode), reload = true to
markdown and github (SSE push after each pandoc compile), and remove
synctex = true from latex (the -synctex=1 arg in latex.args remains
for .synctex.gz generation).

* refactor(init): replace synctex field and validation with reload

Problem: ProviderConfig still declared synctex and validated it, but
the field is being dropped in favour of the general-purpose reload.

Solution: replace the synctex annotation and vim.validate call with the
reload field, accepting boolean | string[] | function.

* feat(compiler): support long-running watch processes and SSE reload

Problem: compile() only supports one-shot invocations, requiring a
BufWritePost autocmd for watch mode and leaving HTML without live-
reload.

Solution: resolve_reload_cmd() maps provider.reload (function or table)
to a command; when present, compile() spawns it as a long-running
process instead of building a one-shot cmd from provider.cmd + args.
toggle() detects long-running providers and toggles the process
directly instead of registering a BufWritePost autocmd. When
reload = true and output is .html, the SSE server is invoked after
each successful compile. status() reports is_reload processes as
watching, not compiling. stop_all() also stops the SSE server.

* fix(compiler): format is_longrunning and annotate is_reload field

Problem: stylua required is_longrunning to be on one line; lua-ls
warned about undefined field is_reload on preview.Process.

Solution: inline the boolean expression and add is_reload? to the
preview.Process annotation.

* refactor: rename compile/toggle commands to build/watch

Problem: `compile` and `toggle` are accurate but unintuitive — `compile`
sounds academic and `toggle` says nothing about what it toggles.

Solution: rename the public API and `:Preview` subcommands to `build`
(one-shot) and `watch` (live preview). Internal compiler functions are
unchanged. No aliases for old names — clean break.
2026-03-03 16:41:47 -05:00

65 lines
1.4 KiB
Lua

local M = {}
local handlers = {
build = function()
require('preview').build()
end,
stop = function()
require('preview').stop()
end,
clean = function()
require('preview').clean()
end,
watch = function()
require('preview').watch()
end,
open = function()
require('preview').open()
end,
status = function()
local s = require('preview').status()
local parts = {}
if s.compiling then
table.insert(parts, 'compiling with "' .. s.provider .. '"')
else
table.insert(parts, 'idle')
end
if s.watching then
table.insert(parts, 'watching')
end
vim.notify('[preview.nvim]: ' .. table.concat(parts, ', '), vim.log.levels.INFO)
end,
}
---@param args string
local function dispatch(args)
local subcmd = args ~= '' and args or 'build'
local handler = handlers[subcmd]
if handler then
handler()
else
vim.notify('[preview.nvim]: unknown subcommand: ' .. subcmd, vim.log.levels.ERROR)
end
end
---@param lead string
---@return string[]
local function complete(lead)
return vim.tbl_filter(function(s)
return s:find(lead, 1, true) == 1
end, vim.tbl_keys(handlers))
end
function M.setup()
vim.api.nvim_create_user_command('Preview', function(opts)
dispatch(opts.args)
end, {
nargs = '?',
complete = function(lead)
return complete(lead)
end,
desc = 'Build, stop, clean, watch, open, or check status of document preview',
})
end
return M