Cleans up component Initialization (#29891)

* Cleans up component Initialization

* Add LoadComponent()

code/datums/components/README.md

@@ -30,14 +30,18 @@ Stands have a lot of procs which mimic mob procs. Rather than inserting hooks fo
     * Lazy associated list of type -> component/list of components.
 1. `/datum/component/var/enabled` (protected, boolean)
     * If the component is enabled. If not, it will not react to signals
-    * TRUE by default
+    * `TRUE` by default
 1. `/datum/component/var/dupe_mode` (protected, enum)
-    * How multiple components of the exact same type are handled when added to the datum.
+    * How duplicate component types are handled when added to the datum.
         * `COMPONENT_DUPE_HIGHLANDER` (default): Old component will be deleted, new component will first have `/datum/component/proc/InheritComponent(datum/component/old, FALSE)` on it
         * `COMPONENT_DUPE_ALLOWED`: The components will be treated as separate, `GetComponent()` will return the first added
         * `COMPONENT_DUPE_UNIQUE`: New component will be deleted, old component will first have `/datum/component/proc/InheritComponent(datum/component/new, TRUE)` on it
+1. `/datum/component/var/dupe_type` (protected, type)
+    * Definition of a duplicate component type
+        * `null` means exact match on `type`
+        * Any other type means that and all subtypes
 1. `/datum/component/var/list/signal_procs` (private)
-    * Associated lazy list of signals -> callbacks that will be run when the parent datum recieves that signal
+    * Associated lazy list of signals -> `/datum/callback`s that will be run when the parent datum recieves that signal
 1. `/datum/component/var/datum/parent` (protected, read-only)
     * The datum this component belongs to
 
@@ -56,6 +60,8 @@ Stands have a lot of procs which mimic mob procs. Rather than inserting hooks fo
     * Sends the `COMSIG_COMPONENT_ADDED` signal to the datum
     * All components a datum owns are deleted with the datum
     * Returns the component that was created. Or the old component in a dupe situation where `COMPONENT_DUPE_UNIQUE` was set
+1. `/datum/proc/LoadComponent(component_type(type), ...) -> datum/component` (public, final)
+    * Equivalent to calling `GetComponent(component_type)` where, if the result would be `null`, returns `AddComponent(component_type, ...)` instead
 1. `/datum/proc/ComponentActivated(datum/component/C)` (abstract)
     * Called on a component's `parent` after a signal recieved causes it to activate. `src` is the parameter
     * Will only be called if a component's callback returns `TRUE`
@@ -66,18 +72,24 @@ Stands have a lot of procs which mimic mob procs. Rather than inserting hooks fo
 1. `/datum/proc/SendSignal(signal, ...)` (public, final)
     * Call to send a signal to the components of the target datum
     * Extra arguments are to be specified in the signal definition
-1. `/datum/component/New(datum/parent, ...)` (protected, virtual)
-    * Forwarded the arguments from `AddComponent()`
-1. `/datum/component/Destroy()` (virtual)
+1. `/datum/component/New(datum/parent, ...)` (private, final)
+    * Runs internal setup for the component
+    * Extra arguments are passed to `Initialize()`
+1. `/datum/component/Initialize(...)` (abstract, no-sleep)
+    * Called by `New()` with the same argments excluding `parent`
+    * Component does not exist in `parent`'s `datum_components` list yet, although `parent` is set and may be used
+    * Signals will not be recieved while this function is running
+    * Component may be deleted after this function completes without being attached
+1. `/datum/component/Destroy()` (virtual, no-sleep)
     * Sends the `COMSIG_COMPONENT_REMOVING` signal to the parent datum if the `parent` isn't being qdeleted
     * Properly removes the component from `parent` and cleans up references
-1. `/datum/component/proc/InheritComponent(datum/component/C, i_am_original(boolean))` (abstract)
+1. `/datum/component/proc/InheritComponent(datum/component/C, i_am_original(boolean))` (abstract, no-sleep)
     * Called on a component when a component of the same type was added to the same parent
     * See `/datum/component/var/dupe_mode`
     * `C`'s type will always be the same of the called component
 1. `/datum/component/proc/AfterComponentActivated()` (abstract)
     * Called on a component that was activated after it's `parent`'s `ComponentActivated()` is called
-1. `/datum/component/proc/OnTransfer(datum/new_parent)` (abstract)
+1. `/datum/component/proc/OnTransfer(datum/new_parent)` (abstract, no-sleep)
     * Called before the new `parent` is assigned in `TakeComponent()`, after the remove signal, before the added signal
     * Allows the component to react to ownership transfers
 1. `/datum/component/proc/_RemoveNoSignal()` (private, final)
@@ -93,9 +105,4 @@ Stands have a lot of procs which mimic mob procs. Rather than inserting hooks fo
     * Called when a component recieves any signal and is enabled
     * Default implementation looks if the signal is registered and runs the appropriate proc
 
-### See signals and their arguments in __DEFINES\components.dm
-
-## Examples
-    Material Containers: #29268 (Too many GetComponent calls, but not bad)
-    Slips: #00000 (PR DIS)
-    Powercells: (TODO)
+### See/Define signals and their arguments in __DEFINES\components.dm

code/datums/components/component.dm

@@ -1,22 +1,35 @@
 /datum/component
 	var/enabled = TRUE
 	var/dupe_mode = COMPONENT_DUPE_HIGHLANDER
+	var/dupe_type
 	var/list/signal_procs
 	var/datum/parent
 
 /datum/component/New(datum/P, ...)
+	parent = P
+	var/list/arguments = args.Copy()
+	arguments.Cut(1, 2)
+	Initialize(arglist(arguments))
+
 	var/dm = dupe_mode
 	if(dm != COMPONENT_DUPE_ALLOWED)
-		var/datum/component/old = P.GetExactComponent(type)
-		if(old)
-			switch(dm)
-				if(COMPONENT_DUPE_HIGHLANDER)
-					InheritComponent(old, FALSE)
-					qdel(old)
-				if(COMPONENT_DUPE_UNIQUE)
-					old.InheritComponent(src, TRUE)
-					qdel(src)
-					return
+		var/dt = dupe_type
+		var/datum/component/old 
+		if(!dt)
+			old = P.GetExactComponent(type)
+		else
+			old = P.GetComponent(dt)
+		switch(dm)
+			if(COMPONENT_DUPE_UNIQUE)
+				old.InheritComponent(src, TRUE)
+				parent = null	//prevent COMPONENT_REMOVING signal
+				qdel(src)
+				return
+			if(COMPONENT_DUPE_HIGHLANDER)
+				InheritComponent(old, FALSE)
+				qdel(old)
+	
+	//let the others know
 	P.SendSignal(COMSIG_COMPONENT_ADDED, src)
 	
 	//lazy init the parent's dc list
@@ -50,7 +63,8 @@
 		else	//only component of this type, no list
 			dc[I] = src
 
-	parent = P
+/datum/component/proc/Initialize(...)
+	return
 
 /datum/component/Destroy()
 	enabled = FALSE
@@ -177,6 +191,11 @@
 	var/datum/component/C = new nt(arglist(args))
 	return QDELING(C) ? GetComponent(new_type) : C
 
+/datum/proc/LoadComponent(component_type, ...)
+	. = GetComponent(component_type)
+	if(!.)
+		return AddComponent(arglist(args))
+
 /datum/proc/TakeComponent(datum/component/C)
 	if(!C)
 		return

code/datums/components/slippery.dm

@@ -3,11 +3,10 @@
 	var/lube_flags
 	var/mob/slip_victim
 
-/datum/component/slippery/New(datum/P, _intensity, _lube_flags = NONE)
-	..()
+/datum/component/slippery/Initialize(_intensity, _lube_flags = NONE)
 	intensity = max(_intensity, 0)
 	lube_flags = _lube_flags
-	if(ismovableatom(P))
+	if(ismovableatom(parent))
 		RegisterSignal(COMSIG_MOVABLE_CROSSED, .proc/Slip)
 	else
 		RegisterSignal(COMSIG_ATOM_ENTERED, .proc/Slip)