-Proxies- New implementation contract how can get initial value?

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2

The initialize function will be called only on time, so you can't just update it's parameters and reuse it.

What I'd do in your case is:

  • keep the same initialize method definition
  • add your new variable at the end of the storage
  • add a new method setX to update the value and a getter - getX
  • upgrade to BoxV2
  • call the setX method to update the variable value
// contracts/Box.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.18;

import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";

contract Box is Initializable {
    uint256 public value;
    uint256 public x;

    function initialize(uint256 _value) public initializer {
        value = _value;
    }

    /// @custom:oz-upgrades-unsafe-allow constructor
    constructor() {
        _disableInitializers();
    }

    // Emitted when the stored value changes
    event ValueChanged(uint256 newValue);

    // Stores a new value in the contract
    function store(uint256 newValue) public {
        value = newValue;
        emit ValueChanged(newValue);
    }

    // Reads the last stored value
    function retrieve() public view returns (uint256) {
        return value;
    }

    function setX(uint256 newValue) public {
        x = newValue;
    }

    function getX() public view returns (uint256) {
        return x;
    }
}

Or you have the following alternative: When is initialize() called? - #3 by frangio

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