Explanation of using hammerspoon to watch for configuration changes

hammerspoon-cool.txt

Simple configuration reloading
You may have noticed that while you're editing the config, it's a little bit annoying to have to keep choosing the Reload Config menu item every time you make a change. We can fix that by adding a keyboard shortcut to reload the config:

hs.hotkey.bind({"cmd", "alt", "ctrl"}, "R", function()
  hs.reload()
end)
hs.alert.show("Config loaded")
We have now bound ⌘+⌥+⌃+R to a function that will reload the config and display a simple alert banner on the screen for a couple of seconds.

One important detail to call out here is that hs.reload() destroys the current Lua interpreter and creates a new one. If we had any code after hs.reload() in this function, it would not be called.

Fancy configuration reloading
So we can now manually force a reload, but why should we even have to do that when the computer could do it for us‽

The following snippet introduces another new extension, pathwatcher which will allow us to automatically reload the config whenever the file changes:

function reloadConfig(files)
    doReload = false
    for _,file in pairs(files) do
        if file:sub(-4) == ".lua" then
            doReload = true
        end
    end
    if doReload then
        hs.reload()
    end
end
hs.pathwatcher.new(os.getenv("HOME") .. "/.hammerspoon/", reloadConfig):start()
hs.alert.show("Config loaded")