table.insert is not adding the parameter Lua

Question

I made this little animation handler code, and I want to add the animation grid name, defined in a function, to another table (grids, which is inside a table called sprite), but when I try to insert the new grid into the sprites.grids table it does not work and the code crashes at anim8.newAnimation(grid('1-'... sattin that I gave a nil grid. I don't understand. :( Code:

require("table")

function createSprite(x, y, path)
    love.graphics.setDefaultFilter("nearest", "nearest")
    local sprite = {
        position = {
            x = x,
            y = y
        },
        sprite = love.graphics.newImage(path),
        currentAnimation,
        animations,
        grids = {}
    }

    function sprite:createSpriteGrid(animation, maxFrames)
        animation = anim8.newGrid(self.sprite:getWidth() / maxFrames, self.sprite:getHeight(), self.sprite:getWidth(), self.sprite:getHeight())
        table.insert(self.grids, animation)
    end

    function sprite:setAnimation(grid, maxFrames, time)
        self.currentAnimation = anim8.newAnimation(grid('1-'.. maxFrames .. '', 1), time)
    end

    function sprite:update(dt)
        self.currentAnimation:update(dt)
    end

    function sprite:draw(scale)
        self.currentAnimation:draw(self.sprite, self.position.x, self.position.y, nil, scale)
    end

    return sprite
end

shop = createSprite(630, 160, "assets/shop.png")
shop:createSpriteGrid(shopAnim, 6)
shop:setAnimation(shop.grids.shopAnim, 6, 0.17)

Answer 1

Especially that function is most likely not doing what you want:

    function sprite:createSpriteGrid(animation, maxFrames)
        animation = anim8.newGrid(self.sprite:getWidth() / maxFrames, self.sprite:getHeight(), self.sprite:getWidth(), self.sprite:getHeight())
        table.insert(self.grids, animation)
    end

In words: you pass animation and maxFrames, but never use animation and immediately replace it with your grid. Then you add your grid to the self.grids array, and since its the first entry it will get the index/key 1. Therefore shop.grids.shopAnim is nil, because you never set it. shop.grids[1] would work.