Code improvement v1

code/game/objects/structures/tank_holder.dm

@@ -13,18 +13,17 @@
 
 	resistance_flags = FIRE_PROOF
 
-	var/obj/item/tank = null
+	/// The stored tank. If this is a path, it gets created into contents at Initialize.
+	var/obj/item/tank
 
 /obj/structure/tank_holder/Initialize()
 	. = ..()
 	if(tank)
-		density = TRUE
-		tank = new tank(src)
+		after_put_tank(new tank)
 
 /obj/structure/tank_holder/Destroy()
 	if(tank)
-		tank.forceMove(get_turf(src))
-		tank = null
+		QDEL_NULL(tank)
 	return ..()
 
 /obj/structure/tank_holder/CanAllowThrough(atom/movable/mover, turf/target)
@@ -32,26 +31,24 @@
 	if(istype(mover) && mover.throwing)
 		return TRUE
 
-/obj/structure/closet/examine(mob/user)
+/obj/structure/tank_holder/examine(mob/user)
 	. = ..()
 	. += "<span class='notice'>It is held together by some <b>screws</b>.</span>"
 
 /obj/structure/tank_holder/attackby(obj/item/W, mob/user, params)
 	if(user.a_intent == INTENT_HARM)
 		return ..()
-	if(contents.len != 0)
-		to_chat(user, "<span class='warning'>There's already something in \the [src].</span>")
+	if(contents.len)
+		to_chat(user, "<span class='warning'>There's already something in [src].</span>")
 		return
 
 	if(!W.tank_holder_icon_state)
-		to_chat(user, "<span class='warning'>\The [W] does not fit in \the [src].</span>")
+		to_chat(user, "<span class='warning'>[W] does not fit in [src].</span>")
 		return
 
 	if(!user.transferItemToLoc(W, src))
 		return
-	to_chat(user, "<span class='notice'>You put \the [W] into \the [src].</span>")
-	if(!user.transferItemToLoc(W, src))
-		return
+	to_chat(user, "<span class='notice'>You put [W] into [src].</span>")
 	after_put_tank(W)
 
 /obj/structure/tank_holder/screwdriver_act(mob/living/user, obj/item/I)
@@ -63,8 +60,11 @@
 	deconstruct(TRUE)
 	return TRUE
 
-/obj/structure/table_frame/deconstruct(disassembled = TRUE)
+/obj/structure/tank_holder/deconstruct(disassembled = TRUE)
 	new /obj/item/stack/rods(get_turf(src), 2)
+	if(tank)
+		tank.forceMove(get_turf(src))
+		tank = null
 	qdel(src)
 
 /obj/structure/tank_holder/attack_paw(mob/user)
@@ -73,16 +73,31 @@
 /obj/structure/tank_holder/attack_hand(mob/user)
 	if(!tank)
 		return ..()
-	to_chat(user, "<span class='notice'>You take \the [tank] from \the [src].</span>")
+	if(!Adjacent(user) || issilicon(user))
+		return ..()
+	to_chat(user, "<span class='notice'>You take [tank] from [src].</span>")
 	add_fingerprint(user)
 	user.put_in_hands(tank)
 	after_remove_tank()
 
-/obj/structure/tank_holder/proc/after_put_tank(obj/item/tank)
-	tank = tank
+/obj/structure/tank_holder/handle_atom_del(atom/A)
+	if(A == tank)
+		after_remove_tank()
+	return ..()
+
+/obj/structure/tank_holder/contents_explosion(severity, target)
+	if(tank)
+		tank.ex_act(severity, target)
+
+/// Call this after inserting the tank into contents in order to update references, icon
+/// and density.
+/obj/structure/tank_holder/proc/after_put_tank(obj/item/tank_)
+	tank = tank_
 	icon_state = tank.tank_holder_icon_state
 	density = TRUE
 
+/// Call this after taking the tank from contents in order to update references, icon
+/// and density.
 /obj/structure/tank_holder/proc/after_remove_tank()
 	tank = null
 	icon_state = "holder"
@@ -90,45 +105,36 @@
 
 /obj/structure/tank_holder/oxygen
 	icon_state = "holder_oxygen"
-	density = TRUE
 	tank = /obj/item/tank/internals/oxygen
 
 /obj/structure/tank_holder/anesthetic
 	icon_state = "holder_anesthetic"
-	density = TRUE
 	tank = /obj/item/tank/internals/anesthetic
 
 /obj/structure/tank_holder/oxygen/yellow
 	icon_state = "holder_oxygen_f"
-	density = TRUE
 	tank = /obj/item/tank/internals/oxygen/yellow
 
 /obj/structure/tank_holder/oxygen/red
 	icon_state = "holder_oxygen_fr"
-	density = TRUE
 	tank = /obj/item/tank/internals/oxygen/red
 
 /obj/structure/tank_holder/emergency_oxygen
 	icon_state = "holder_emergency"
-	density = TRUE
 	tank = /obj/item/tank/internals/emergency_oxygen
 
 /obj/structure/tank_holder/emergency_oxygen/engi
 	icon_state = "holder_emergency_engi"
-	density = TRUE
 	tank = /obj/item/tank/internals/emergency_oxygen/engi
 
 /obj/structure/tank_holder/generic
 	icon_state = "holder_generic"
-	density = TRUE
 	tank = /obj/item/tank/internals/generic
 
 /obj/structure/tank_holder/extinguisher
 	icon_state = "holder_extinguisher"
-	density = TRUE
 	tank = /obj/item/extinguisher
 
 /obj/structure/tank_holder/extinguisher/advanced
 	icon_state = "holder_foam_extinguisher"
-	density = TRUE
 	tank = /obj/item/extinguisher/advanced