Intervals

Use interval with on_interval when a widget needs to poll.

local clock

clock = easybar.add(easybar.kind.item, "clock", {
    position = "right",
    order = 10,
    interval = 60,
    label = os.date("%H:%M"),
    on_interval = function()
        clock:set({
            label = os.date("%H:%M"),
        })
    end,
})

Referencing the node itself

When an interval callback needs to reference its own handle, declare the variable before assigning it:

local clock

clock = easybar.add(easybar.kind.item, "clock", {
    interval = 60,
    on_interval = function()
        clock:set({
            label = os.date("%H:%M"),
        })
    end,
})

Do not write this:

local clock = easybar.add(easybar.kind.item, "clock", {
    interval = 60,
    on_interval = function()
        clock:set({
            label = os.date("%H:%M"),
        })
    end,
})

The callback may close over clock before it has been assigned.

When to use intervals

Use intervals for polling:

• package manager state
• shell command output
• API checks
• periodic time-based updates

Use event subscriptions for real events:

• network_change
• wifi_change
• volume_change
• system_woke
• mouse events