Only place tiles on certain other tiles?

[PoisonedPorkchop]

For example, I have an item that lets me place tiles

Code: Select all

data:extend(
{
    {
        type = "item",
        name = "CustomConcrete",
        icon = "__Testing__/graphics/icons/concrete.png",
        flags = {"goes-to-main-inventory"},
        order = "a",
        stack_size = 100,
        place_as_tile =
        {
            result = "customconcrete",
            condition_size = 0,
            condition = { "water-tile" }
        }
    },
})

How do I specify that my concrete can ONLY be placed upon normal concrete? Also, what does the condition, and condition_size affect? At the moment this item allows placing the tile literally anywhere.