I am developing the erc-721 contract. How can I distribute specific nft images created for team members to team members?
Related
Scenario
My Smart contract (SM-A) can be used only if you own a specific NFT created and managed by another contract (SM-B).
If so, it stores additional information inside a mapping property :
msg.sender address
account name
and other properties to cover the SM-A business requirements.
Constraints
I'm the owner of SM-A.
I'm NOT the owner of SM-B and I don't have chance to change anything about it.
Questions
Is there a way for having information if and when the msg.sender sells his NFT from SM-B in order to remove his data from my mapping property stored in SM-A?
If so, how it works the cost of the delete transaction operation?
Will my contract pay for it?
I have an NFT staking contract that issues rewards based on the property rarity of the NFT staked. The four property tiers are 1,2,3 and 4.
When a user clicks stakeNFT(tokenId, nftTier), I use the tokenId to pull the metadata json property from IPFS and send the NFT tier to the smart contract.
The issue here is while this works on the user interface of our website, anyone can use Etherscan directly and input an tier that isn’t in their NFT so as to earn more rewards.
How do I verify the NFT tier based on the tokenId onchain?
How do I make a existing running erc20 to prevent some holders from transacting?
I am trying to do a staking feature. Can I write a new contract to control the existing erc20 contract?
Logic that would affect a token holder's ability to transfer (or have a party transferFrom on the holders behalf) must be written into the contract if you want token transfers to be halted within the contract itself. Therefore, if you already have a contract deployed you would have to deploy a new ERC20 contract that has the logic - if you want the staking mechanism to be within the same contract. Then you would have to transfer balances from the previous version of the contract to the newly deployed contract. While possible, it would incur a gas expense to replicate the contract state. You could have your token holders pay this gas cost by having some sort of mint or recover function that would read the old contract balance for an address, create the balance on the new contract, and then mark the balance as transferred.
Alternatively, to your second question, you could facilitate the staking with an additional contract that users would set an allowance to within the ERC20 contract. Then, users could interact with something like a stake function on this new staking contract. The staking contract would use the transferFrom ERC20 function to transfer tokens from the owner to the staking contract's address after incrementing the user's staked token amount within the staking contract. This would record the holder's staking "credit" and tie the tokens up by transferring their ownership to the staking contract. Users could then unstake which would decrement the user's staked token amount and transfer the tokens back from the staking contract's address to the token holder's address. This type of approach has more moving pieces but could be a more flexible step while developing the mechanism as you can deploy new versions of the staking contract without having to redeploy the ERC20 contract or transfer balances. Users would be able to transfer like normal throughout multiple versions of the staking contract and extracting tokens from previous versions of the staking contracts would be gas-efficient.
Everyone can create ethereum token by solidity codes but don't know how can this token integrate as payment gateway in ecommerce website.
For real project . This token need frontend web wallet /android wallet and integration to every website as payment.
Plz suggest me .how can find this way.
What need more to study.
Token is not a payment gateway. If i understand your question correctly, you are asking, how can you interact with a token that you have created through Solidity from frontend. One use case would be how people can use the token that you have created to purchase some item. For this the users should already be holding the tokens. This can be bought from an ICO or from an exchange. Basically there's a couple of functions in ERC20 token i.e., approve() and transfer() that will approve apps like exchanges to perform transactions on behalf of the owner of the token. Once the users have those tokens they can purchase items from it. Again, you have to write the logic how and what you expect users to do.
ERC20 Token is works likes Currency.And solidity is a programming language. which we used for write the smart contract. if you want to invoke your function then you need to create wallet account ,after that you can do transaction using with web3js. you can get ether for testing purpose from faucet.Basically these are functions in ERC20 token i.e., approve() and transfer() that will perform transactions
I don't suggest using ERC20 tokens as payment method.
Ethereum network is not fast enough,you need 30 confirmations to make sure you received the token, some times the delay can be 1 day
Cost is high, when you transfer token ,usually you have a smart contract, it costs lots of gas
Ether price is not stable, it drops 90% of value from Jan 2018 to Dec 2018. it will be hard for estore to maintain profit.
However if you still want to do that, yes, you can create your own gateway using tokens as your accepted currency.
How can I get lists of ERC20, ERC721 and ERC827 tokens in a particular Ethereum wallet address? Also I would like to be able to get the name, symbol, logo, and balance from the main net.
ERC-721 includes an optional interface (optional means the contract implementor can choose if they want to implement it) to enumerate tokens owned by a specific account.
Su Squares implements this feature, but few other contracts do it.
You can use tools like Etherscan, Enjinx Blockchain Explorer or write your own interface to a Ethereum JSON RPC host to collect the data.
I don't think you can do a total data dive per address. I think you have to go the other way around, meaning looking if a contract contains a certain token. For the major tokens like EOS, this should be easy with MEW.
But if you're looking for some obscure tokens such as the ones below, you probably have to add them to MEW manually to check:
Crap Coin (CRP)
Ingrid Is a Horrible Human Coin (iHH)
Banana Coin