Trying to understand update

[devansh08]

I'm trying to understand how update works.

As I'm understanding now, without any conditions/update set if I have an init or provider function it gets called on any key press (?).
But what I'm noticing is even if I set update to false, the same still happens. Is this not what update was supposed to prevent ?

Example:

      local ViMode = {
        init = function(self)
          self.bruh = vim.loop.gettimeofday()
        end,
        provider = function(self)
          return vim.loop.gettimeofday()
        end,
        update = false,
      }

      local SL_Left = {
        ViMode,
      }
      require("heirline").setup({
        statusline = {
          SL_Left,
        },
      })

Note: This example is just to try and understand how the options work.

[rebelot]

by default the statusline is redrawn whenever neovim thinks it is most appropriate (redraw conditions are not really documented). At each redraw fired by neovim, the entire statusline is re-evaluated. This might be inefficient for some components that need to do some heavy tasks but don't need to be re-evaluated often, maybe only when directory is changed, buffer is saved, etc. the update field allows to control on which events the component will be re-evaluated, instead of using its cached value. condition, but not init, is always evaluated, regardless. Setting update = false indeed is not doing what you think it should be doing, it is just saying that you don't want to specify what events should trigger the component re-evaluation, an thus is using standard internal events that trigger redrawstatus. If you want something to be computed at plugin initialization time, and hold a reference to it from within the components, use the static field.

[devansh08]

Thanks for the answer!

condition, but not init, is always evaluated, regardless.

In what cases is init not evaluated ?

[rebelot]

In the case that the update field is present and the condition for updating is not met.