State Registrar

The State Registrar provides a robust system for tracking and managing state in your Aurora modules. It's particularly useful for tracking time-windowed events and maintaining state access.

Core Implementation

The state registrar consists of two main components:

• StateExpression: The core class for managing individual states
• StateManager: A global manager for all state expressions

Creating a State Expression

local myState = Aurora.StateExpression:New("my_state", 0)

The New method accepts:

• name: Unique identifier for the state
• default: Initial value (defaults to 0)

State Expression Properties

Each state expression contains:

{
    name = "string",        -- Unique identifier
    value = any,           -- Current state value
    lastUpdate = number,   -- Last update timestamp
    window = number       -- Time window in seconds (default: 5)
}

Core Methods

-- Register an event handler
myState:RegisterHandler("EVENT_NAME", function(self, now, ...)
    -- Handle the event
end)

-- Update state based on an event
myState:Update("EVENT_NAME", ...)

-- Set the time window
myState:SetWindow(10) -- 10 seconds

Accessing State Values

-- Using __call metamethod
local value = myState()

-- Direct access
local directValue = myState.value

Advanced Example: Damage Tracker

Here's a comprehensive example that demonstrates the power of the state registrar by implementing a damage tracking system:

local StateExpression = Aurora.StateExpression

-- Create damage tracking state
local damageTaken = StateExpression:New("damage_taken")
damageTaken.hits = {} -- Store individual hits

-- Cleanup function for managing the hit window
local function cleanupOldHits(self, now)
    local windowStart = now - self.window
    local removed = 0

    -- Remove old hits
    while self.hits[1] and self.hits[1].time < windowStart do
        table.remove(self.hits, 1)
        removed = removed + 1
    end
    
    -- Recalculate total
    local total = 0
    for _, hit in ipairs(self.hits) do
        total = total + (tonumber(hit.amount) or 0)
    end
    
    -- Update only if changed
    if total ~= self.value then
        self.value = total
    end
    
    return removed
end

-- Setup event handling
local f = CreateFrame("Frame")
f:RegisterEvent("UNIT_COMBAT")

-- Periodic cleanup
local timerFrame = CreateFrame("Frame")
timerFrame:SetScript("OnUpdate", function(self, elapsed)
    if #damageTaken.hits > 0 then
        cleanupOldHits(damageTaken, GetTime())
    end
end)

-- Event forwarding
f:SetScript("OnEvent", function(self, event, ...)
    damageTaken:Update(event, ...)
end)

-- Register damage handler
damageTaken:RegisterHandler("UNIT_COMBAT", function(self, now, unitTarget, event, flagText, amount, schoolMask)
    if unitTarget ~= "player" then return end

    -- Process damage amount and type
    local damageAmount = tonumber(amount) or 0
    local damageType = "Unknown"
    
    -- Map damage school types
    local schoolTypes = {
        [1] = "Physical",
        [2] = "Holy",
        [4] = "Fire",
        [8] = "Nature",
        [16] = "Frost",
        [32] = "Shadow",
        [64] = "Arcane"
    }
    damageType = schoolTypes[schoolMask] or "Unknown"
    
    -- Record hit details
    table.insert(self.hits, {
        time = now,
        amount = damageAmount,
        type = damageType,
        isCrit = flagText == "CRITICAL",
        isCrushing = flagText == "CRUSHING",
        isGlancing = flagText == "GLANCING"
    })
    
    cleanupOldHits(self, now)
end)

-- Register in global state
Aurora.state.damage_taken = damageTaken

Using the Damage Tracker

-- Get total damage in current window
local totalDamage = damageTaken()

-- Analyze recent hits
for _, hit in ipairs(damageTaken.hits) do
    if hit.isCrit then
        print(string.format("%s critical hit for %d!", 
            hit.type, hit.amount))
    end
end

-- Get damage by type
local function getDamageByType(type)
    local total = 0
    for _, hit in ipairs(damageTaken.hits) do
        if hit.type == type then
            total = total + hit.amount
        end
    end
    return total
end

local physicalDamage = getDamageByType("Physical")