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Remove presets (#3637)

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Co-authored-by: Francisco Giordano <frangio.1@gmail.com>
Co-authored-by: JulissaDantes <julissadcj@gmail.com>
This commit is contained in:
Hadrien Croubois
2022-11-25 16:46:47 +01:00
committed by GitHub
parent 887985413c
commit 4a9db80cb9
26 changed files with 7 additions and 1025 deletions
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8
docs/modules/ROOT/pages/erc1155.adoc
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@ -143,11 +143,3 @@ contract MyContract is ERC1155Holder {
----
We can also implement more complex scenarios using the xref:api:token/ERC1155.adoc#IERC1155Receiver-onERC1155Received-address-address-uint256-uint256-bytes-[`onERC1155Received`] and xref:api:token/ERC1155.adoc#IERC1155Receiver-onERC1155BatchReceived-address-address-uint256---uint256---bytes-[`onERC1155BatchReceived`] functions.
[[Presets]]
== Preset ERC1155 contract
A preset ERC1155 is available, https://github.com/OpenZeppelin/openzeppelin-contracts/blob/release-v4.7/contracts/token/ERC1155/presets/ERC1155PresetMinterPauser.sol[`ERC1155PresetMinterPauser`]. It is preset to allow for token minting (create) - including batch minting, stop all token transfers (pause) and allow holders to burn (destroy) their tokens. The contract uses xref:access-control.adoc[Access Control] to control access to the minting and pausing functionality. The account that deploys the contract will be granted the minter and pauser roles, as well as the default admin role.
This contract is ready to deploy without having to write any Solidity code. It can be used as-is for quick prototyping and testing, but is also suitable for production environments.
NOTE: Contract presets are now deprecated in favor of https://wizard.openzeppelin.com[Contracts Wizard] as a more powerful alternative.

34
docs/modules/ROOT/pages/erc20-supply.adoc
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@ -54,40 +54,12 @@ contract ERC20WithMinerReward is ERC20 {
As we can see, `_mint` makes it super easy to do this correctly.
[[modularizing-the-mechanism]]
== Modularizing the Mechanism
There is one supply mechanism already included in Contracts: `ERC20PresetMinterPauser`. This is a generic mechanism in which a set of accounts is assigned the `minter` role, granting them the permission to call a `mint` function, an external version of `_mint`.
This can be used for centralized minting, where an externally owned account (i.e. someone with a pair of cryptographic keys) decides how much supply to create and for whom. There are very legitimate use cases for this mechanism, such as https://medium.com/reserve-currency/why-another-stablecoin-866f774afede#3aea[traditional asset-backed stablecoins].
The accounts with the minter role don't need to be externally owned, though, and can just as well be smart contracts that implement a trustless mechanism. We can in fact implement the same behavior as the previous section.
[source,solidity]
----
contract MinerRewardMinter {
ERC20PresetMinterPauser _token;
constructor(ERC20PresetMinterPauser token) {
_token = token;
}
function mintMinerReward() public {
_token.mint(block.coinbase, 1000);
}
}
----
This contract, when initialized with an `ERC20PresetMinterPauser` instance, and granted the `minter` role for that contract, will result in exactly the same behavior implemented in the previous section. What is interesting about using `ERC20PresetMinterPauser` is that we can easily combine multiple supply mechanisms by assigning the role to multiple contracts, and moreover that we can do this dynamically.
TIP: To learn more about roles and permissioned systems, head to our xref:access-control.adoc[Access Control guide].
[[automating-the-reward]]
== Automating the Reward
So far our supply mechanisms were triggered manually, but `ERC20` also allows us to extend the core functionality of the token through the xref:api:token/ERC20.adoc#ERC20-_beforeTokenTransfer-address-address-uint256-[`_beforeTokenTransfer`] hook (see xref:extending-contracts.adoc#using-hooks[Using Hooks]).
So far our supply mechanism was triggered manually, but `ERC20` also allows us to extend the core functionality of the token through the xref:api:token/ERC20.adoc#ERC20-_beforeTokenTransfer-address-address-uint256-[`_beforeTokenTransfer`] hook (see xref:extending-contracts.adoc#using-hooks[Using Hooks]).
Adding to the supply mechanism from previous sections, we can use this hook to mint a miner reward for every token transfer that is included in the blockchain.
Adding to the supply mechanism from the previous section, we can use this hook to mint a miner reward for every token transfer that is included in the blockchain.
[source,solidity]
----
@ -110,4 +82,4 @@ contract ERC20WithAutoMinerReward is ERC20 {
[[wrapping-up]]
== Wrapping Up
We've seen two ways to implement ERC20 supply mechanisms: internally through `_mint`, and externally through `ERC20PresetMinterPauser`. Hopefully this has helped you understand how to use OpenZeppelin Contracts and some of the design principles behind it, and you can apply them to your own smart contracts.
We've seen how to implement a ERC20 supply mechanism: internally through `_mint`. Hopefully this has helped you understand how to use OpenZeppelin Contracts and some of the design principles behind it, and you can apply them to your own smart contracts.

8
docs/modules/ROOT/pages/erc20.adoc
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@ -75,11 +75,3 @@ So if you want to send `5` tokens using a token contract with 18 decimals, the m
```solidity
transfer(recipient, 5 * (10 ** 18));
```
[[Presets]]
== Preset ERC20 contract
A preset ERC20 is available, https://github.com/OpenZeppelin/openzeppelin-contracts/blob/release-v4.7/contracts/token/ERC20/presets/ERC20PresetMinterPauser.sol[`ERC20PresetMinterPauser`]. It is preset to allow for token minting (create), stop all token transfers (pause) and allow holders to burn (destroy) their tokens. The contract uses xref:access-control.adoc[Access Control] to control access to the minting and pausing functionality. The account that deploys the contract will be granted the minter and pauser roles, as well as the default admin role.
This contract is ready to deploy without having to write any Solidity code. It can be used as-is for quick prototyping and testing, but is also suitable for production environments.
NOTE: Contract presets are now deprecated in favor of https://wizard.openzeppelin.com[Contracts Wizard] as a more powerful alternative.

8
docs/modules/ROOT/pages/erc721.adoc
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@ -80,11 +80,3 @@ For more information about the `tokenURI` metadata JSON Schema, check out the ht
NOTE: You'll notice that the item's information is included in the metadata, but that information isn't on-chain! So a game developer could change the underlying metadata, changing the rules of the game!
TIP: If you'd like to put all item information on-chain, you can extend ERC721 to do so (though it will be rather costly) by providing a xref:utilities.adoc#base64[`Base64`] Data URI with the JSON schema encoded. You could also leverage IPFS to store the tokenURI information, but these techniques are out of the scope of this overview guide.
[[Presets]]
== Preset ERC721 contract
A preset ERC721 is available, https://github.com/OpenZeppelin/openzeppelin-contracts/blob/release-v4.7/contracts/token/ERC721/presets/ERC721PresetMinterPauserAutoId.sol[`ERC721PresetMinterPauserAutoId`]. It is preconfigured with token minting (creation) with token ID and URI auto generation, the ability to stop all token transfers (pause), and it allows holders to burn (destroy) their tokens. The contract uses xref:access-control.adoc[Access Control] to control access to the minting and pausing functionality. The account that deploys the contract will be granted the minter and pauser roles, as well as the default admin role.
This contract is ready to deploy without having to write any Solidity code. It can be used as-is for quick prototyping and testing but is also suitable for production environments.
NOTE: Contract presets are now deprecated in favor of https://wizard.openzeppelin.com[Contracts Wizard] as a more powerful alternative.