import "@thirdweb-dev/contracts/extension/Drop.sol";

Drop is an extension meant for distributing ERC20 or ERC721 tokens. It allows setting up multiple claim phases unlike DropSinglePhase. This series of claim phases is ordered by their respective startTimestamp.

This extension implements the 'Drop' distribution mechanism: set multiple claim phases with restrictions such as a price to charge, an allowlist etc. for the public / allowlisted mint of your tokens.

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The Drop extension is an abstract contract, and expects you to implement the following functions by yourself:

This is an example smart contract demonstrating how to inherit from this extension and override the functions to add (optional) custom functionality.

// SPDX-License-Identifier: Apache-2.0
pragma solidity ^0.8.0;

import "@thirdweb-dev/contracts/extension/Drop.sol";
import "@thirdweb-dev/contracts/base/ERC20Base.sol";
import "@thirdweb-dev/contracts/lib/CurrencyTransferLib.sol";

/// This is an EXAMPLE of usage of `Drop` for distributing ERC20 tokens.

contract MyContract is ERC20Base, Drop {
    /*//////////////////////////////////////////////////////////////
                            Constructor
    //////////////////////////////////////////////////////////////*/

    constructor(address _defaultAdmin, string memory _name, string memory _symbol)
        ERC20Base(_defaultAdmin, _name, _symbol)
    {}

    /*//////////////////////////////////////////////////////////////
                        Internal (overrideable) functions
    //////////////////////////////////////////////////////////////*/

    /// @dev Runs before every `claim` function call.
    function _beforeClaim(
        uint256 _tokenId,
        address _receiver,
        uint256 _quantity,
        address _currency,
        uint256 _pricePerToken,
        AllowlistProof calldata _allowlistProof,
        bytes memory _data
    ) internal virtual override {
      // Your custom implementation logic here
    }

    /// @dev Runs after every `claim` function call.
    function _afterClaim(
        uint256 _tokenId,
        address _receiver,
        uint256 _quantity,
        address _currency,
        uint256 _pricePerToken,
        AllowlistProof calldata _allowlistProof,
        bytes memory _data
    ) internal virtual override {
      // Your custom implementation logic here
    }

    /// @dev Collects and distributes the primary sale value of tokens being claimed.
    function _collectPriceOnClaim(
        address _primarySaleRecipient,
        uint256 _quantityToClaim,
        address _currency,
        uint256 _pricePerToken
    ) internal virtual override {
        if (_pricePerToken == 0) {
            return;
        }

        uint256 totalPrice = (_quantityToClaim * _pricePerToken) / 1 ether;
        require(totalPrice > 0, "quantity too low");

        if (_currency == CurrencyTransferLib.NATIVE_TOKEN) {
            require(msg.value == totalPrice, "Must send total price.");
        }

        address saleRecipient = _primarySaleRecipient;
        CurrencyTransferLib.transferCurrency(
            _currency,
            msg.sender,
            saleRecipient,
            totalPrice
        );
    }

    /// @dev Transfers the tokens being claimed.
    function _transferTokensOnClaim(address _to, uint256 _quantityBeingClaimed)
        internal
        virtual
        override
        returns (uint256)
    {
        _mint(_to, _quantityBeingClaimed);
        return 0;
    }

    /// @dev Checks whether platform fee info can be set in the given execution context.
    function _canSetClaimConditions()
        internal
        view
        virtual
        override
        returns (bool)
    {
        return msg.sender == owner();
    }
}

None of the base contracts implement this extension.