I am learning about NFT minting by using remix to run test code on testnets. Now the function seems to be working as the ETH balance is reduced by the amount of mint price I set, but I can't check the NFTs the given wallet was holding. Is there a way to view it somewhere to check if the NFT is successfully minted?
UPDATE: I see that people can use test nets with their own wallet to receive those NFTs and view them on platforms like Opensea. But is it possible to do the same with VM?
Whether you are using a virtual machine or not, should not have the ability to use Remix or access any testnets. So it is possible. Remix and Ethereum wallets use HTTP to communicate with JSON-RPC nodes that allow your wallets, transactions and other to function.
Related
I am new to smartcontract and start writing some demo code in Solidity to work with Ropsten testing network. I see that I can use send/transfer method in the contract to transfer ether to other accounts. One question about it is that is contract the only way to transfer ether? Can I transfer ether without a contract?
I understand the concept of the contract but not sure whether it is a required thing in Ethereum. When I deploy a contract to the network, it will be sitting in a new block and all transactions generated from this contract are in the same block? Am I understand correctly?
You do not need a smart contract to sign or send a transaction. The transferring of ETH is built into the protocol. This can be accomplished by using libraries such as web3 or ethers if you're a developer. If you're not a developer, this can be accomplished by using tools such as Metamask.
Steps to send a transaction using ethers.js:
Instantiate your provider and signer using ethers.providers. and Signer.
Then sign a transaction using signer.signTransaction.
Use provider to send the transaction using provider.sendTransaction.
References:
Ethers.js: https://docs.ethers.io/v5/api/
web3.js: https://web3js.readthedocs.io/en/v1.5.2/
metamask: https://metamask.io
I am using Ethereum network to deploy smart contract. The contract is written in Solidity and I am using Remix IDE to do the deploy and testing. I am using testing network at the moment.
What I don't understand is that when I deploy a smart contract to Ethereum network, does it create a new block on the blockchain? My contract may send transaction to different account when it is running. Whether this transaction is inside the block of the smart contract? Once I deploy the contract, it should be running inside the network. Whenever there is a method call on the contract, does it always generate a transaction in the block?
There's a slight difference between live networks (e.g. Ethereum mainnet or Ropsten testnet) and emulators (such as Remix VM or Ganache).
When you want to deploy a contract, its compiled bytecode is passed as the data field of a transaction that doesn't have a recipient (the to field is omitted).
On a live network, the transaction is broadcasted to the network, and waiting in the mempool to be mined.
When a miner mines this transaction, the EVM on their machine calculates the state changes that were made during its execution (in other words, the contract deployment) and broadcasts the state changes (e.g. storing the contract bytecode under the newly created address storage) to the rest of the network.
However, each instance of an EVM emulator usually runs on one machine (e.g. in your browser in case of Remix) and doesn't have access to a network of miners. Plus it would be ineffective to wait for an external miner to mine your transaction every time during development.
So when you send a transaction on an emulator, it's locally executed and wrapped in a new block right away.
So to answer your questions:
Does deploy a contract mean create a new block in blockchain?
live networks - no
emulators - yes
Whenever there is a method call on the contract, does it always generate a transaction in the block?
There's a difference between a transaction (read-write) and a call (read-only). For transactions, see above. Read-only calls are not mined at all (so they are free), and they are only invoked on the machine of your node provider (or in the emulator).
I'm working on a Dapp for testing Ethereum smart contracts.
I have followed along with this tutorial: https://github.com/Quintor/angular-truffle-box and got the Truffle Dapp working with Ganache-CLI, making me able to do Crypto (I.e. Ethereum) transactions from one to another wallet on this blockchain.
*Note, this is a testing environment so no real Eth are transferred.
The problem I currently encounter is that transactions are direct, and not like the times that are displayed as an option. (Like here, https://ibb.co/ccR8k0J)
The idea is that the more Ethereum (Cryptocurrency) you pay as a fee, the faster the transaction will be done. I wonder if anyone knows how to simulate these times, but on a local blockchain instead of a deployed one.
"ganache doesn't have options to set the consensus mechanism. You could look at puppeth to quickly spin up a geth instance with whatever consensus you want."
By #Stephen S
Does anyone know if I can deploy my own smart contract or run/host a solidity code via my own website? I am following this Youtube tutorial by Decypher Media.
If I'm correct, the testrpc address localhost:8545 means that I am deploying the contract as being part of a private blockchain that is only local to my pc, right? This is the case for development. So if I would want to actually deploy the contract as an actual Ethereum node or to the Ethereum blockchain itself, would I just have to replace the localhost:8545 with the actual URL? I am not totally familiar with this yet, but I am really trying to develop something on Ethereum.
I am looking at creating a contract that sends a token to a dynamic number of eth addresses (i.e. today I may have to send tokens to 10 eth addresses, tomorrow I may do it for 15). So, instead of firing the contract for each token which would be time-consuming, I would like to do it automatically/seamlessly. But I want to be able to run my solidity code and handle the contract through my own website instead of running it on the ethereum wallet application or somewhere else.
Anyone, please share some ideas on how we can achieve this, or maybe a summary/outline of the steps that we would need to take to achieve it. Any help would be great! Thanks!
You have many possibilities to achieve this. It depends what you really want to do.
1 - With testrpc :
The easiest way to do this is to run testrpc on a server, for example a free aws-server or azure and expose the testrpc on internet. Then you can replace localhost:8545 by :8545 or using a dns to by-pass the ip.
2 - With a private Ethereum Blockchain :
If you want a real private Ethereum Blockchain, you can build a private node on a aws/azure/google server and expose this node to internet. See this, to learn a bit more : https://blockgeeks.com/two-node-setup-of-a-private-ethereum/
3 - Use a ethereum public network
You can send your smart contract to the public ethereum testnet and then use Metamask and web3js to connect your website to the ethereum testnet. More information for Metamask and how to deploy a contract with Metamask : https://karl.tech/learning-solidity-part-1-deploy-a-contract/ and here https://citywebconsultants.co.uk/blog/blockchain/introducing-ethereum-development-part-1-metamask-and-web3
New to solidity and blockchain in general, I tried to make transactions and deploy smart contracts but it seems that we need ethereum to "pay" these actions. Is there any way to get free or "fake" ethereum to easily test transactions and smart contracts ?
Sure, you have basicly two options if you go for the testnet. Don't test stuff on the public main network.
Mine in developer mode
Run geth with the developer flag.
geth --dev --mine --minerthreads 1
From help:
--dev Developer mode: pre-configured private network with several debugging flags
--mine Enable mining
--minerthreads value Number of CPU threads to use for mining (default: 12)
This runs a private testnetwork with your own chain. The miner runs low on one thread to generate new blocks and this way you get testnet Ether in your private network which can be used to pay the fees.
Drain the morden faucet
Join the morden public testnet.
geth --testnet
From help:
--testnet Morden network: pre-configured test network with modified starting nonces (replay protection)
This is the public testnet called morden. It might be too hard to mine but you can just request free testnet ether from the public wei faucet.
In addition to the free testnet Ether method in my other answer, you could also look into development tools and integrated environments for developing smart contracts. Most of them either do not require a real blockchain backend with Ether fees or simulate an Ethereum virtual machine (EVM) and simulate the deployment of smart contracts and decentralized applications.
Among others there are:
Mix (Desktop) and Remix (Web) IDEs for smart contract debugging and development
Solidity Browser (Web) IDE for smart contract debugging
Truffle a development framework for Ethereum
Embark a framework for decentralized apps
Dapple and Dappsys toolchains for fast smart contract development
See also questions tagges with IDE on Ethereum Stack Exchange.