Add a tutorial for taco shop payouts
This commit is contained in:
Matej Sima
parent
ec4db9b01e
commit
b5087298f7
@ -2,6 +2,8 @@
|
||||
id: cheat-sheet
|
||||
title: Cheat Sheet
|
||||
---
|
||||
<div class="cheatsheet">
|
||||
|
||||
|
||||
<!--DOCUSAURUS_CODE_TABS-->
|
||||
<!--PascaLIGO-->
|
||||
@ -32,6 +34,9 @@ title: Cheat Sheet
|
||||
|Variant *(pattern)* matching|<pre><code>const a: action = Increment(5);<br/>case a of<br/>| Increment n -> n + 1<br/>| Decrement n -> n - 1<br/>end</code></pre>|
|
||||
|Records|<pre><code>type person is record<br/> age: int ;<br/> name: string ;<br/>end<br/><br/>const john : person = record<br/> age = 18;<br/> name = "John Doe";<br/>end<br/><br/>const name: string = john.name;</code></pre>|
|
||||
|Maps|<pre><code>type prices is map(nat, tez);<br/><br/>const prices : prices = map<br/> 10n -> 60mtz;<br/> 50n -> 30mtz;<br/> 100n -> 10mtz;<br/>end<br/><br/>const price: option(tez) = prices[50n];</code></pre>|
|
||||
|Contracts & Accounts|<pre><code>const destinationAddress : address = "tz1...";<br/>const contract : contract(unit) = get_contract(destinationAddress);</code></pre>|
|
||||
|Transactions|<pre><code>const payment : operation = transaction(unit, amount, receiver);</code></pre>|
|
||||
|
||||
<!--END_DOCUSAURUS_CODE_TABS-->
|
||||
|
||||
<!--END_DOCUSAURUS_CODE_TABS-->
|
||||
</div>
|
||||
@ -0,0 +1,37 @@
|
||||
type taco_supply is record
|
||||
current_stock : nat;
|
||||
max_price : tez;
|
||||
end
|
||||
type taco_shop_storage is map(nat, taco_supply);
|
||||
|
||||
const ownerAddress: address = "tz1TGu6TN5GSez2ndXXeDX6LgUDvLzPLqgYV";
|
||||
const donationAddress: address = "tz1KqTpEZ7Yob7QbPE4Hy4Wo8fHG8LhKxZSx";
|
||||
|
||||
function buy_taco (const taco_kind_index: nat ; var taco_shop_storage : taco_shop_storage) : (list(operation) * taco_shop_storage) is
|
||||
begin
|
||||
// Retrieve the taco_kind from the contract's storage
|
||||
const taco_kind : taco_supply = get_force(taco_kind_index, taco_shop_storage);
|
||||
|
||||
const current_purchase_price : tez = taco_kind.max_price / taco_kind.current_stock;
|
||||
|
||||
if amount =/= current_purchase_price then
|
||||
// we won't sell tacos if the amount isn't correct
|
||||
fail("Sorry, the taco you're trying to purchase has a different price");
|
||||
else
|
||||
// Decrease the stock by 1n, because we've just sold one
|
||||
taco_kind.current_stock := abs(taco_kind.current_stock - 1n);
|
||||
|
||||
// Update the storage with the refreshed taco_kind
|
||||
taco_shop_storage[taco_kind_index] := taco_kind;
|
||||
|
||||
const receiver: contract(unit) = get_contract(ownerAddress);
|
||||
const donationReceiver: contract(unit) = get_contract(donationAddress);
|
||||
|
||||
const donationAmount: tez = amount / 10n;
|
||||
|
||||
const operations : list(operation) = list
|
||||
transaction(unit, amount - donationAmount, receiver);
|
||||
transaction(unit, donationAmount, donationReceiver);
|
||||
end;
|
||||
|
||||
end with (operations, taco_shop_storage)
|
||||
@ -0,0 +1,180 @@
|
||||
---
|
||||
id: tezos-taco-shop-payout
|
||||
title: Paying out profits from the Taco Shop
|
||||
---
|
||||
|
||||
In the [previous tutorial](tutorials/get-started/tezos-taco-shop-smart-contract.md) we've learned how to setup & interact with the LIGO CLI. Followed by implementation of a simple Taco Shop smart contract for our entepreneur Pedro. In this tutorial we'll make sure Pedro has access to tokens that people have spent at his shop when buying tacos.
|
||||
|
||||
|
||||
<br/>
|
||||
<img src="/img/tutorials/get-started/tezos-taco-shop-payout/get-money.svg" width="50%" />
|
||||
|
||||
<div style="opacity: 0.7; text-align: center; font-size: 10px;">
|
||||
<div>Icons made by <a href="https://www.flaticon.com/authors/smashicons" title="Smashicons">Smashicons</a> from <a href="https://www.flaticon.com/" title="Flaticon">www.flaticon.com</a> is licensed by <a href="http://creativecommons.org/licenses/by/3.0/" title="Creative Commons BY 3.0" target="_blank">CC 3.0 BY</a></div>
|
||||
</div>
|
||||
|
||||
|
||||
## Analyzing the current contract
|
||||
|
||||
### **`taco-shop.ligo`**
|
||||
```
|
||||
type taco_supply is record
|
||||
current_stock : nat;
|
||||
max_price : tez;
|
||||
end
|
||||
type taco_shop_storage is map(nat, taco_supply);
|
||||
|
||||
function buy_taco (const taco_kind_index: nat ; var taco_shop_storage : taco_shop_storage) : (list(operation) * taco_shop_storage) is
|
||||
begin
|
||||
// Retrieve the taco_kind from the contract's storage
|
||||
const taco_kind : taco_supply = get_force(taco_kind_index, taco_shop_storage);
|
||||
|
||||
const current_purchase_price : tez = taco_kind.max_price / taco_kind.current_stock;
|
||||
|
||||
if amount =/= current_purchase_price then
|
||||
// we won't sell tacos if the amount isn't correct
|
||||
fail("Sorry, the taco you're trying to purchase has a different price");
|
||||
else
|
||||
// Decrease the stock by 1n, because we've just sold one
|
||||
taco_kind.current_stock := abs(taco_kind.current_stock - 1n);
|
||||
|
||||
// Update the storage with the refreshed taco_kind
|
||||
taco_shop_storage[taco_kind_index] := taco_kind;
|
||||
end with ((nil : list(operation)), taco_shop_storage)
|
||||
```
|
||||
|
||||
### Purchase price formula
|
||||
Pedro's Taco Shop contract currently enables customers to buy tacos, at a computed price based on a simple formula.
|
||||
|
||||
```
|
||||
const current_purchase_price : tez = taco_kind.max_price / taco_kind.current_stock;
|
||||
```
|
||||
|
||||
### Replacing *spendable* smart contracts
|
||||
However, due to the [recent protocol upgrade](http://tezos.gitlab.io/mainnet/protocols/004_Pt24m4xi.html) of the Tezos mainnet, Pedro can't access the tokens stored in his Shop's contract directly. This was previously possible via `spendable` smart contracts, which are no longer available in the new protocol. We will have to implement a solution to access tokens from the contract programatically.
|
||||
|
||||
---
|
||||
|
||||
## Designing a payout scheme
|
||||
|
||||
Pedro is a standalone bussines owner, and in our case, he doesn't have to split profits / earnings of the taco shop with anyone. So for the sake of simplicity, we'll payout all the earned XTZ directly to Pedro right after a succesful taco purchase.
|
||||
|
||||
This means that after all the *purchase conditions* of our contract are met - e.g. correct amount is sent to the contract - we'll not only decrease the supply of the individual purchased *taco kind*, but we'll also transfer this amount in a *subsequent transaction* to Pedro's personal address.
|
||||
|
||||
## Forging a payout transaction
|
||||
|
||||
### Defining the recipient
|
||||
In order to send tokens, we will need a receiver address - which in our case will be Pedro's personal account. Additionally we'll wrap the given address as a *`contract(unit)`* - which represents either a contract with no parameters, or an implicit account.
|
||||
|
||||
```
|
||||
const ownerAddress : address = "tz1TGu6TN5GSez2ndXXeDX6LgUDvLzPLqgYV";
|
||||
const receiver : contract(unit) = get_contract(ownerAddress);
|
||||
```
|
||||
|
||||
> Would you like to learn more about addresses, contracts and operations in LIGO? Check out the [LIGO cheat sheet](language-basics/cheat-sheet.md)
|
||||
|
||||
### Adding the transaction to the list of output operations
|
||||
Now we can transfer the `amount` received by `buy_taco` to Pedro's `ownerAddress`. We will do so by forging a `transaction(unit, amount, receiver)` within a list of operations returned at the end of our contract.
|
||||
|
||||
|
||||
```
|
||||
const payoutOperation : operation = transaction(unit, amount, receiver) ;
|
||||
const operations : list(operation) = list
|
||||
payoutOperation
|
||||
end;
|
||||
```
|
||||
|
||||
---
|
||||
|
||||
## Finalizing the contract
|
||||
|
||||
### **`taco-shop.ligo`**
|
||||
```
|
||||
type taco_supply is record
|
||||
current_stock : nat;
|
||||
max_price : tez;
|
||||
end
|
||||
type taco_shop_storage is map(nat, taco_supply);
|
||||
|
||||
const ownerAddress: address = "tz1TGu6TN5GSez2ndXXeDX6LgUDvLzPLqgYV";
|
||||
|
||||
function buy_taco (const taco_kind_index: nat ; var taco_shop_storage : taco_shop_storage) : (list(operation) * taco_shop_storage) is
|
||||
begin
|
||||
// Retrieve the taco_kind from the contract's storage
|
||||
const taco_kind : taco_supply = get_force(taco_kind_index, taco_shop_storage);
|
||||
|
||||
const current_purchase_price : tez = taco_kind.max_price / taco_kind.current_stock;
|
||||
|
||||
if amount =/= current_purchase_price then
|
||||
// we won't sell tacos if the amount isn't correct
|
||||
fail("Sorry, the taco you're trying to purchase has a different price");
|
||||
else
|
||||
// Decrease the stock by 1n, because we've just sold one
|
||||
taco_kind.current_stock := abs(taco_kind.current_stock - 1n);
|
||||
|
||||
// Update the storage with the refreshed taco_kind
|
||||
taco_shop_storage[taco_kind_index] := taco_kind;
|
||||
|
||||
const receiver : contract(unit) = get_contract(ownerAddress);
|
||||
const payoutOperation : operation = transaction(unit, amount, receiver);
|
||||
const operations : list(operation) = list
|
||||
payoutOperation
|
||||
end;
|
||||
|
||||
end with (operations, taco_shop_storage)
|
||||
```
|
||||
|
||||
|
||||
### Dry-run the contract
|
||||
|
||||
To confirm that our contract is valid, we can dry run it. As a result we see a *new operation* in the list of returned operations to be executed subsequently.
|
||||
|
||||
```
|
||||
ligo dry-run taco-shop.ligo --syntax pascaligo --amount 1 buy_taco 1n "map
|
||||
1n -> record
|
||||
current_stock = 50n;
|
||||
max_price = 50000000mtz;
|
||||
end;
|
||||
2n -> record
|
||||
current_stock = 20n;
|
||||
max_price = 75000000mtz;
|
||||
end;
|
||||
end"
|
||||
```
|
||||
|
||||
<img src="/img/tutorials/get-started/tezos-taco-shop-payout/dry-run-1.png" />
|
||||
<div style="opacity: 0.7; text-align: center; font-size: 12px; margin-top:-24px;">
|
||||
<b>Operation(...bytes)</b> included in the output
|
||||
</div>
|
||||
|
||||
<br/>
|
||||
|
||||
**Done! Our tokens are no longer locked in the contract, and instead they are sent to Pedro's personal account/wallet.**
|
||||
|
||||
---
|
||||
|
||||
## 👼 Bonus: donating part of the profits
|
||||
|
||||
Because Pedro is a member of the (STA) Specialty Taco Association, he has decided to donate **10%** of the earnings to the STA. We'll just add a `donationAddress` to the contract, and compute a 10% donation sum from each taco purchase.
|
||||
|
||||
```
|
||||
const ownerAddress: address = "tz1TGu6TN5GSez2ndXXeDX6LgUDvLzPLqgYV";
|
||||
const donationAddress: address = "tz1KqTpEZ7Yob7QbPE4Hy4Wo8fHG8LhKxZSx";
|
||||
```
|
||||
|
||||
```
|
||||
const receiver : contract(unit) = get_contract(ownerAddress);
|
||||
const donationReceiver : contract(unit) = get_contract(donationAddress);
|
||||
|
||||
const donationAmount: tez = amount / 10n;
|
||||
|
||||
const operations : list(operation) = list
|
||||
// Pedro will get 90% of the amount
|
||||
transaction(unit, amount - donationAmount, receiver);
|
||||
transaction(unit, donationAmount, donationReceiver);
|
||||
end;
|
||||
```
|
||||
|
||||
This will result into two operations being subsequently executed on the blockchain:
|
||||
- Donation transfer (10%)
|
||||
- Pedro's profits (90%)
|
||||
@ -16,6 +16,6 @@
|
||||
"Road Map": ["contributors/road-map/short-term", "contributors/road-map/long-term"]
|
||||
},
|
||||
"tutorials": {
|
||||
"Get Started": ["tutorials/get-started/tezos-taco-shop-smart-contract"]
|
||||
"Get Started": ["tutorials/get-started/tezos-taco-shop-smart-contract", "tutorials/get-started/tezos-taco-shop-payout"]
|
||||
}
|
||||
}
|
||||
|
||||
@ -228,6 +228,10 @@ body > div.fixedHeaderContainer > div > header > div > nav > ul > li:nth-child(5
|
||||
background: transparent;
|
||||
}
|
||||
|
||||
.cheatsheet tr > td:first-of-type {
|
||||
min-width: 240px;
|
||||
}
|
||||
|
||||
@media only screen and (min-device-width: 360px) and (max-device-width: 736px) {
|
||||
}
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user