Set Price Extrinsic

Now that we our Pallet set up to handle balances, let's actually use them.

In this step, we will create an extrinsic which allows the owner of a kitty to set a price for the kitty.

Set Price

The set price extrinsic is pretty straight forward.

As we noted in the last step, we allow the price field of a kitty to be Option<BalanceOf<T>>, where None denotes a kitty which is not for sale, and Some(price) denotes a kitty which is for sale at some price.

With this in mind, our set_price extrinsic will also accept an Option<BalanceOf<T>> so that a user can put the kitty on or off the market.

Your Turn

In this step, you will scaffold the extrinsic and internal functions for set_price.

• Create a new event PriceSet with the fields noted in the template.
• Create a new extrinsic set_price with the params noted in the template.
• Create a new internal function do_set_price which simply deposits the PriceSet event.

We will actually populate the logic for do_set_price in the next step.