Event Handler

The Event Handler provides a streamlined way to handle both combat log events and normal WoW events. It offers filtering capabilities and structured event data.

Basic Usage

local EventHandler = Aurora.EventHandler

-- Register a combat log event handler
EventHandler:RegisterEvent("SPELL_CAST_SUCCESS", function(eventData)
    if eventData.source.guid == UnitGUID("player") then
        print(string.format("You cast %s", C_Spell.GetSpellLink(eventData.params[1])))
    end
end)

-- Register a normal WoW event handler
EventHandler:RegisterNormalEvent("PLAYER_ENTERING_WORLD", function()
    print("Player entered the world")
end)

Event Registration

Combat Log Events

EventHandler:RegisterEvent(eventType, handlerFunction)

• eventType: Combat log event type (e.g., "SPELL_CAST_SUCCESS")
• handlerFunction: Function that receives the structured event data

Normal Events

EventHandler:RegisterNormalEvent(eventType, handlerFunction)

• eventType: WoW event name (e.g., "PLAYER_ENTERING_WORLD")
• handlerFunction: Function that receives the raw event parameters

Event Data Structure

Combat log events provide structured data:

eventData = {
    timestamp = 1234567890,
    event = "SPELL_CAST_SUCCESS",
    source = {
        guid = "Player-1234-5678",
        name = "PlayerName",
        flags = sourceFlags,
        raidFlags = sourceRaidFlags
    },
    dest = {
        guid = "Target-1234-5678",
        name = "TargetName",
        flags = destFlags,
        raidFlags = destRaidFlags
    },
    params = { spellId, spellName, ... } -- Additional event-specific parameters
}

Event Filtering

Add filters to process only specific events:

-- Only process events where the player is the source
EventHandler:AddFilter("SPELL_CAST_SUCCESS", function(eventData)
    return eventData.source.guid == UnitGUID("player")
end)

Examples

Track Player Spells

EventHandler:RegisterEvent("SPELL_CAST_SUCCESS", function(eventData)
    if eventData.source.guid == UnitGUID("player") then
        local spellId, spellName = unpack(eventData.params)
        print(string.format("Cast %s (ID: %d)", spellName, spellId))
    end
end)

Monitor Interrupts

EventHandler:RegisterEvent("SPELL_INTERRUPT", function(eventData)
    local _, _, _, extraSpellId, extraSpellName = unpack(eventData.params)
    print(string.format("%s interrupted %s's %s", 
        eventData.source.name,
        eventData.dest.name,
        extraSpellName))
end)

Track Group Changes

EventHandler:RegisterNormalEvent("GROUP_ROSTER_UPDATE", function()
    print("Group composition changed")
end)

Best Practices

Performance

• Use filters to reduce unnecessary event processing
• Keep event handlers lightweight
• Consider batching frequent events
• Clean up handlers when no longer needed

Common Pitfalls

• Don't register too many handlers for the same event
• Be careful with string operations in high-frequency events
• Remember that some events fire very frequently
• Handle nil cases in event data

Common Combat Log Events

Click to view common combat log events

-- Spell Events
"SPELL_CAST_START"      -- When a spell cast begins
"SPELL_CAST_SUCCESS"    -- When a spell cast completes
"SPELL_CAST_FAILED"     -- When a spell cast fails
"SPELL_AURA_APPLIED"    -- When a buff/debuff is applied
"SPELL_AURA_REMOVED"    -- When a buff/debuff is removed
"SPELL_INTERRUPT"       -- When a spell is interrupted
"SPELL_DISPEL"         -- When a buff/debuff is dispelled

-- Damage & Healing
"SPELL_DAMAGE"         -- Spell damage
"SWING_DAMAGE"         -- Melee damage
"SPELL_HEAL"          -- Healing
"SPELL_PERIODIC_HEAL" -- HoT healing

-- Unit Events
"UNIT_DIED"           -- When a unit dies
"PARTY_KILL"         -- When your party kills something

Event Processing

• Combat log events provide more structured data than normal events