Low Code Carbon Credit Implementation

[parv0888]

Purpose

Adds Carbon Credit Sample Implementation.

Changes

Adds Marketplace, Carbon Project Fractionalizer to Carbon Credits & Carbon Project NFT contracts.
Adds Frontend to interact with the contracts and backend
Adds backend & Indexer / Listener to listen for a process events from the contracts.

Checklist

• My code follows the style of this project.
• The code compiles without warnings.
• I have performed a self-review of the changes.
• I have documented my code, in particular the intent of the
  hard-to-understand areas.
• (If necessary) I have updated the CHANGELOG.

CLA acceptance

By submitting the contribution I accept the terms and conditions of the
Contributor License Agreement v1.0

• link: https://developers.concordium.com/CLAs/Contributor-License-Agreement-v1.0.pdf

• I accept the above linked CLA.

[parv0888]

@DOBEN : Kindly note that changes which were done in the previous PR related to Metadata URL also would have to be done in this PR since the same approch was used. Im on it.

[DOBEN]

Works very well.

I had a problem with buying the tokens from the marketplace. I think initially the logic was to call updateOperator and then to sell a token by transferring it from the seller account to the buyer account. Now the front end transfers the token to the marketplace and then when buying a token the token needs to be transferred from the marketPlaceContract to the buyer account. Currently, the smart contract logic still uses the seller account to the buyer account which results in an -4 error.

https://github.com/Concordium/concordium-dapp-examples/blob/53a9e11df4117131ed2498[…]dits-marketplace/contracts/src/carbon_credit_market/transfer.rs

        .cis2
        .transfer::<State<S>, ContractTokenId, ContractTokenAmount, ()>(
            host,
            Transfer {
                amount: params.quantity,
                to: Receiver::Account(params.to),
                token_id: params.token_id,
                from: Address::Account(params.owner),
                data: AdditionalData::empty(),
            },
        )?;

    logger.log(&ContractEvent::TokenTransferred(TokenTransferredEvent {
        token_id: params.token_id,
        token_contract: params.cis_contract_address,
        from: Address::Account(params.owner),
        to: Address::Account(params.to),
        amount: params.quantity,
    }))?;

There is an issue when using googleMail:

• buying a token when log-in with googleMail (error: Private key as second argument is required)

[parv0888]

Works very well.

I had a problem with buying the tokens from the marketplace. I think initially the logic was to call updateOperator and then to sell a token by transferring it from the seller account to the buyer account. Now the front end transfers the token to the marketplace and then when buying a token the token needs to be transferred from the marketPlaceContract to the buyer account. Currently, the smart contract logic still uses the seller account to the buyer account which results in an -4 error.

https://github.com/Concordium/concordium-dapp-examples/blob/53a9e11df4117131ed2498[…]dits-marketplace/contracts/src/carbon_credit_market/transfer.rs

        .cis2
        .transfer::<State<S>, ContractTokenId, ContractTokenAmount, ()>(
            host,
            Transfer {
                amount: params.quantity,
                to: Receiver::Account(params.to),
                token_id: params.token_id,
                from: Address::Account(params.owner),
                data: AdditionalData::empty(),
            },
        )?;

    logger.log(&ContractEvent::TokenTransferred(TokenTransferredEvent {
        token_id: params.token_id,
        token_contract: params.cis_contract_address,
        from: Address::Account(params.owner),
        to: Address::Account(params.to),
        amount: params.quantity,
    }))?;

There is an issue when using googleMail:

• buying a token when log-in with googleMail (error: Private key as second argument is required)

Thanks @DOBEN
this has been fixed.

[DOBEN]

@parv0888 There is something not picked up in the TransferEvent in the Fractionalizer contract. It looks to me related to the above changes. E.g. that the front end expects an AccountAddress as the By field but it is a smart contract address now.

See the associated event By field is empty when checking the events in the Fractionalizer contract now. This field should not be empty.
.

I wonder if the intention of the indexer is to pick up all the CIS2 Transfer events from a specific token contract or only a subset of it? Are these Transfer events the Transfer event as specified in the CIS2 standard or some custom Transfer events? E.g. are the indexer only picking up a subset of Transfer events e.g. only the ones that go from an account address to the carbonCreditMarketPlace?

There are no Transfer events from the account to the carbonCreditMarketplaceSmartContract currently. Just wonder if that is intended or not (equally for the project token)?

[DOBEN]

Please add a note about this project and the low-code-nft-marketplace in the Read.me:
https://github.com/Concordium/concordium-dapp-examples/blob/main/README.md

[DOBEN]

I have used the private key as REACT_APP_WERT_PRIVATE_KEY that was provided to me and used the remaining environmental variables for WERT/GOOGLE_AUTHENTICATE as they were from the previous PR before they were removed. Seems there is something else I need to set up differently.

[parv0888]

HI @DOBEN
I did test this and also have sent you the changes on linkedin.
seems to be working for me. Please do specify is the provided values does not work for you.
Please do try any other gmail / google account once.

Thanks

[parv0888]

@parv0888 There is something not picked up in the TransferEvent in the Fractionalizer contract. It looks to me related to the above changes. E.g. that the front end expects an AccountAddress as the By field but it is a smart contract address now.

See the associated event By field is empty when checking the events in the Fractionalizer contract now. This field should not be empty. .

I wonder if the intention of the indexer is to pick up all the CIS2 Transfer events from a specific token contract or only a subset of it? Are these Transfer events the Transfer event as specified in the CIS2 standard or some custom Transfer events? E.g. are the indexer only picking up a subset of Transfer events e.g. only the ones that go from an account address to the carbonCreditMarketPlace?

There are no Transfer events from the account to the carbonCreditMarketplaceSmartContract currently. Just wonder if that is intended or not (equally for the project token)?

This has been fixed

[DOBEN]

Well done. The project looks very good in general.

[DOBEN]

Suggested change

	* Wert integration is **disabled by default**. To enable it, set thefollowing environment variables in the [.env](./market-ui/.env) file. Contract [Wert sales](https://wert.io/for-partners) to get these credentials
	* Wert integration is **disabled by default**. To enable it, set the following environment variables in the [.env](./market-ui/.env) file. Contact [Wert sales](https://wert.io/for-partners) to get these credentials