SecureStateDriver

A SecureStateDriver allows code snippets to execute upon game state changes expressible using macro conditionals.

SecureStateDriver.lua implements two kinds of SecureStateDriver:

AttributeDriver (formerly StateDriver) securely controls any type of Frame by toggling its visibility or setting customizable attributes
UnitWatch securely controls a unit frame by toggling its visibility or state-unitexists attribute

Combined with SecureHandlerStateTemplate or SecureUnitButtonTemplate, these SecureStateDrivers faciliate code execution in the RestrictedEnvironment to alter protected values during combat.

AttributeDriver[]

RegisterAttributeDriver(frame, attribute, conditional)
UnregisterAttributeDriver(frame, attribute)
RegisterStateDriver(frame, state, conditional)         -- depreciated
UnregisterStateDriver(frame, state)                    -- depreciated

Creates or cancels an AttributeDriver. Frames execute code snippets insecurely using OnAttributeChanged or securely by inheriting SecureHandlerStateTemplate.

The depreciated StateDriver functions forward their arguments to AttributeDriver ones after prepending the second argument with "state-".

frame

Frame - The AttributeDriver acts on this frame by toggling its visibility or setting its attributes

attribute

String - Any arbitrary identifier, but converted to lower case with the following results:

"state-visibility" causes an AttributeDriver to securely call Region:Show() when the macro conditional evaluates to "show" or Region:Hide() when it evaluates to "hide"
Other values cause an AttributeDriver to securely call Frame:SetAttribute(state, result) using the outcome of the macro conditional's evaluation as result

state: String - Prepended with "state-" and then used similar to attribute (ie. state "visibility" becomes attribute "state-visibility")
conditional: String - A macro conditional parsable by SecureCmdOptionParse

UnitWatch[]

RegisterUnitWatch(frame, asState)
UnregisterUnitWatch(frame, asState)

Creates or cancels a UnitWatch. Frames must inherit SecureUnitButtonTemplate and have an assigned unitId using Frame:SetAttribute("unit", "unitId")

frame

Frame - The UnitWatch acts on this frame by toggling its visibility or setting its attributes

asState

Boolean - Controls the behaviour of a UnitWatch with the following results:

True causes the UnitWatch to securely call Frame:SetAttribute("state-unitexists", result) using the outcome of the macro conditonal's evaluation as result
False causes the UnitWatch to securely call Region:Show() when the macro conditional evaluates to "show" or Region:Hide() when it evaluates to "hide"

Examples[]

Showing/hiding a unit frame

local frame = CreateFrame("Button", "MyParty1", UIParent, "SecureUnitButtonTemplate")
frame:SetAttribute("unit", "party1")
RegisterUnitWatch(frame)
    
frame:SetPoint("CENTER")
frame:SetSize(50, 50)
frame:SetBackdrop({ bgFile = "Interface\\BUTTONS\\WHITE8X8", tile = true, tileSize = 8 })
frame:SetBackdropColor(1, 0, 0)

The snippet above will display a clickable unit frame for the "party1" unit (consisting solely of a red square in the center of your screen) only when the unit exists.

Responding to custom states

local frame = CreateFrame("Frame", "MyStatefulFrame", UIParent, "SecureHandlerStateTemplate")
RegisterStateDriver(frame, "petstate", "[@pet,noexists] nopet; [@pet,help] mypet; [@pet,harm] mcpet")
frame:SetAttribute("_onstate-petstate", [[ -- arguments: self, stateid, newstate
    if newstate == "nopet" then
        print("Where are you, kitty?")
    elseif newstate == "mypet" then
        print("Oh hai, kitty!")
    elseif newstate == "mcpet" then
        print("Curse your sudden but inevitable betrayal, kitty!") -- Your pet is hostile to you.
    end
]])

RegisterStateDriver just implements RegisterAttributeDriver

function RegisterStateDriver(frame, state, conditional)
  return RegisterAttributeDriver(frame, "state-"..state, values);
end

Notes[]

Conditionals are evaluated by SecureStateDriverManager's OnUpdate and OnEvent handlers:
- Before each new frame, but not faster than STATE_DRIVER_UPDATE_THROTTLE (currently 0.2 sec)^[1]
- Immediately upon the following events:

Patch changes[]

Patch 5.0.4 (2012-08-28): Conditionals now evaluate on GROUP_ROSTER_UPDATE^[2]
Patch 4.0.1 (2010-10-12): AttributeDriver added, but StateDriver remains as a bridge function.^[3]
Patch 2.1.0 (2007-05-22): StateDriver and UnitWatch added.^[4]

References[]

^ 2007-05-22, SecureStateDriver.lua, version 2.1.0.6692, near line 54, archived at Townlong-Yak
^ 2012-08-21, SecureStateDriver.lua, version 5.0.4.16016, near line 178, archived at Townlong-Yak
^ 2010-10-19, SecureStateDriver.lua, version 4.0.1.13164, near line 25, archived at Townlong-Yak
^ 2007-05-22, SecureStateDriver.lua, version 2.1.0.6692, near line 8, archived at Townlong-Yak

[1] 2007-05-22, SecureStateDriver.lua, version 2.1.0.6692, near line 54, archived at Townlong-Yak

[2] 2012-08-21, SecureStateDriver.lua, version 5.0.4.16016, near line 178, archived at Townlong-Yak

[3] 2010-10-19, SecureStateDriver.lua, version 4.0.1.13164, near line 25, archived at Townlong-Yak

[4] 2007-05-22, SecureStateDriver.lua, version 2.1.0.6692, near line 8, archived at Townlong-Yak

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