Good to know Zgoo is a thing. I checked the component and noticed GetNamedChild was Blacklisted so I switched to using GetChild. The updated snippet is:
Lua Code:
local slot = wm:CreateControlFromVirtual("Bar_Slot_" .. i, BarTracker.guiFront, BarTracker.guiTemplate)
slot:SetAnchor(TOPLEFT, BarTracker.guiFront, TOPLEFT, 0, 0)
slot:SetHidden(false)
local tex = slot:GetChild(1)
tex:SetTexture("/esoui/art/icons/ability_templar_purifying_light.dds")
Upon inspecting the texture component, GetTextureFileName now returns the correct path (as opposed to empty string) but I still don't see the texture, nor a white square. I have also removed the anchor within the texture component from the XML file.
Here is what the UI looks like: