All Questions
32 questions
9
votes
4
answers
26k
views
How to use web3 to send money from wallet A to wallet B?
var myContract = web3.eth.contract(abi);
var address = contract address;
var contract_data = myContract.at(address);
var sender = '0xd3aaa525c087978133abb517593ea334f16abd1f';
var receiver = '...
- 101
6
votes
1
answer
6k
views
Web3 retrieving latest transactions [duplicate]
Is there any way in the Web3 Javascript API to retrieve the latest, let's say five, transactions that were done on the blockchain?
The only option I can think of, is by using web3.eth.getBlock(web3....
- 81
4
votes
1
answer
2k
views
how can I get the data returned from solidity function from transaction id in web3js when a solidity function is callled?
I want to get the return data written in solidity function in web3js .
I am using the web3.min.js from the truffle pet-shop package as the web3 library . Everything is working fine when calling the ...
- 155
3
votes
1
answer
727
views
MetaMask blocks Web3 requests
I just set up a Block Explorer to interact with my private blockchain.
The private Blockchain runs in a VM. The host system connects to the Block explorer (also on VM).
When I have meta mask ...
- 3,462
3
votes
1
answer
547
views
Difference between .sign and .signTransaction
I have this two kind of codes and I would like to know what is the difference between them:
First. .sign()
var tx = new Tx(rawtx);
tx.sign(privateKey);
Second .signTransaction()
web3.eth.accounts....
- 511
2
votes
2
answers
3k
views
Can anybody Point out the Difference between Web3.eth.sendTransaction and web3.eth.signTransaction?
Do we need to sign the transaction by web3.eth.signTransaction after initiating transaction via web3.eth.sendTransaction.
for example:
when I do:
web3.eth.sendTransaction({
from: accs[0],
...
- 818
2
votes
1
answer
3k
views
Difference between `0x01` and `0x1` status code?
Sometimes when running Ganache I receive status code 0x01, sometimes 0x1. Should I treat both as successful executions?
- 359
2
votes
1
answer
379
views
sendTransaction from iPhone app
How do I call sendTransaction from within an iPhone app?
I was thinking of running a web to Geth proxy where the iPhone app would call the Api exposed by the proxy which in turn calls my self hosted ...
- 309
2
votes
1
answer
1k
views
How to simulate buy?
im new in web3js and i got a problem. Would be nice, if you could help me. Ive been trying to solve it myself for days...
Im trying to simulate a buy transaction (after its working i will do the sell ...
2
votes
1
answer
1k
views
Why do transaction receipts not include the value of Ether transferred?
I'm writing some logic to identify the currency used in an ethereum transaction, and am wondering the following:
web3.eth.getTransaction returns a value field that indicates the value transferred in ...
- 1,720
2
votes
1
answer
373
views
Problem creating my own wallet with multiple accounts
I have a local blockchain where I have deployed a contract. I want to interact with it sending multiple responses at the same time. For this propose, I cannot use Metamask to confirm each transaction. ...
- 511
2
votes
0
answers
329
views
What does sendSignedTransaction return?
I want to call a method in the smart contract (UpdateWeather) that goes through several steps before returning the result (an integer). I use sendSingendTransaction but I have doubts.
Is the ...
- 83
2
votes
0
answers
149
views
(UPDATED) Send signed transaction interacting with a contract [duplicate]
I have a local blockchain where I have deployed a contract. I want to interact with it sending multiple responses at the same time. For this propose, I cannot use Metamask to confirm each transaction. ...
- 511
2
votes
0
answers
315
views
geth taking a long time to mine a block
I'm using the embark framework to deploy some smart contracts to a private Ethereum network. The problem is, the network behaves differently on separate machines, even though they're similarly spec'd -...
- 614
1
vote
2
answers
3k
views
How do EOAs work and what is their interaction with smart contracts?
After reading and searching online, I still have many doubts about how EOAs work and their relationship with smart contracts.
The idea behind my dapp is to allow users to make reservations. It also ...
- 187
1
vote
1
answer
77
views
Which component sends a transaction and which component subscribes to an event?
I am working on an ethereum project but I have some doubts. I have a backend that connects to the blockchain via web3.js. To connect to the blockchain I use a geth node.
I understand that the sequence ...
- 83
1
vote
1
answer
4k
views
web3.eth.filter({fromBlock:0, toBlock: 'latest', address: account}) not working?
My goal here is to list all transaction from an given account, without any success yet.
I wonder why I always have an empty result when I'm using this web3.eth.filter. I know there is a valid ...
- 1,508
1
vote
2
answers
4k
views
How to simulate buy / trade transactions on local without submitting them to blockchain?
I'm learning a little about blockchain and there is something i'm stucked with.
I'm working with pairs from BSC network, and I'd like to get some information if the token can be bought and sold before ...
- 21
1
vote
1
answer
1k
views
Get time when the transaction was included in your node
Is there any way to obtain the time when you have received a transaction? I would like to know when is a Smart contract included in my node. (local testnet)
- 511
1
vote
0
answers
563
views
How can we get other transactions result like using window.web3.eth.getTransactionReceipt on our own transaction?
If I send a transaction, I can watch the result using window.web3.eth.getTransactionReceipt like this:
tradeContract.methods.test(...args).send({
from: pubData.user.address,
gas: gasAmount
})
....
- 336
1
vote
0
answers
174
views
Interact with a contract using Web3 Wallet
I am trying to interact with a contract without a provider as Metamask/Mist. I know that web3 has an option to create a new Wallet and I have been seeing code examples about that but all of them ...
- 511
0
votes
1
answer
202
views
How do you get the UTXOs a transaction is spending using web3.js?
I'm unsure how to get the UTXOs that a transaction is spending.
Here's what I have so far. I get transaction details from txhash
web3.eth.getTransaction("...
- 229
0
votes
1
answer
3k
views
Iterating over transactions in a private blockchain using web3.js [duplicate]
This question is similar to this one. I'm trying to iterate through all transactions in a private block chain and look for specific data sent in the 'data' fields of each transactions. Is the ...
- 5,284
0
votes
1
answer
3k
views
How get estimated gas before sending the transaction?
How do you get the "estimated gas" from a "swapExactETHForTokens" function? As shown in metamask (before one can accept the purchase)
Binance Smart Chain (BSC)
From the pancakeswap ...
0
votes
1
answer
21
views
What would web3.js respond with in this case?
I have a mapping to a struct in my contract
mapping (uint=> Student) students;
struct Student {
bool passed;
}
Now I want to call a particular student with a particular ID to see if he has ...
- 263
0
votes
2
answers
2k
views
Check when a block is mined
Is it possible to know when a block is mined? Is there any timestamp or event/subscription?
- 511
0
votes
1
answer
41
views
Is it possible to see changes that have been made by a user on blockchain?
Is it possible to see every changes that have been made to the block chain from various accounts.In other words is it possible to see what changes have been done by a user to, say its location(a field ...
0
votes
0
answers
680
views
How to get and decode logs of all transactions of a block in web3?
How to get and decode logs of all transactions of a block in web3?
My question is very similar to:
Is there a way to get the logs for all transactions in a block?
But the suggestions were given using ...
- 13
0
votes
1
answer
194
views
Await ethereum transaction in javascript by only knowing the transaction hash
Is there a way to check if a transaction was mined/it's being mined by only knowing the transaction hash?
I'm using ethers.js
- 67
0
votes
0
answers
52
views
Is it possible to schedule a transaction to execute after a certain amount of time in ethereum? [duplicate]
Is it possible to schedule a transaction to execute after a certain amount of time in ethereum? For example, I have a dapp where after two weeks I want to call a getRefund function on the smart ...
- 83
0
votes
2
answers
343
views
Unable to send ether to account
I am trying to send ehter using this code
web3.eth.accounts.wallet.add(privateKey);
web3.eth.sendTransaction({
to:someAddress,
from:onwer,
value:amount*1,
...
- 39
0
votes
0
answers
41
views
Latest Block Number 0 [duplicate]
I am running geth with this command :
geth --fast --cache=512 --ws --wsorigins="*" --rpc --rpccorsdomain="*" --wsapi "db,eth.subscribe,net,ssh,miner,web3,personal,admin" --datadir /media/username/...
- 205