Trending questions in Blockchain

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HyperledgerFabric : *SampleChaincode does not implement shim.Chaincode error

The reason you are getting this error ...READ MORE

Oct 29, 2018 in Blockchain by Omkar
• 69,180 points
1,773 views
0 votes
1 answer

HyperLedger Composer: Failed to load connector module “composer-connector-embedded” for connection profile “testprofile”

First, update your devDependencies in package.json "devDependencies": { ... "composer-admin": ...READ MORE

Nov 2, 2018 in Blockchain by Omkar
• 69,180 points
1,591 views
+3 votes
1 answer

When I ran truffle init, I got this error:

Hey there @Davidala! The error says that it ...READ MORE

Oct 29, 2018 in Blockchain by Omkar
• 69,180 points
1,637 views
0 votes
1 answer

Hyperledger Fabric: How to retrieve success payload via nodejs client?

The channel.sendTransactionProposal generates a Response object You ...READ MORE

Oct 30, 2018 in Blockchain by Omkar
• 69,180 points
1,708 views
0 votes
1 answer

How to issue regular payouts to multiple wallets?

The cheapest way to do this is ...READ MORE

Oct 30, 2018 in Blockchain by Christine
• 15,750 points
1,737 views
0 votes
1 answer

Why do the resultant hash after mining has a leading no. of zeroes in Blockchain verification?

This is chosen by the DIFFICULTY EQUATION. In ...READ MORE

Aug 10, 2018 in Blockchain by Christine
• 15,750 points
5,190 views
0 votes
1 answer

How to get value from solidity contract using java?

web3j caters for this very use case. It ...READ MORE

Sep 28, 2018 in Blockchain by slayer
• 29,370 points
3,078 views
0 votes
1 answer

Blockchain: Installing an earlier version of ethereum using apt-get on

geth does not make the previous version available ...READ MORE

Oct 10, 2018 in Blockchain by Omkar
• 69,180 points
2,558 views
0 votes
2 answers

Web socket API session automatically disconnecting

Yes, the code given by Christine works! ...READ MORE

Aug 29, 2018 in Blockchain by digger
• 26,740 points
4,340 views
0 votes
1 answer

How to input realtime data from google sheets into urlfetch google scripts?

Based on your title I hope to ...READ MORE

Oct 12, 2018 in Blockchain by Perry
• 17,100 points
2,449 views
0 votes
1 answer

Hyperledger Fabric: build error "files are missing SPDX-License-Identifier headers"

Try this: make peer orderer peer-docker orderer-docker tools-docker ...READ MORE

Oct 30, 2018 in Blockchain by Omkar
• 69,180 points
1,669 views
0 votes
1 answer

UnhandledPromiseRejectionWarning: Insufficient funds error in Ethereum: NodeJS web3

sendSignedTransaction returns a promiEvent onto which you can chain then and catch: web3.eth.sendSignedTransaction('0x' + ...READ MORE

Oct 15, 2018 in Blockchain by Omkar
• 69,180 points
2,314 views
0 votes
1 answer

Not able to invoke a contract in Ethereum Private chain using geth

Hope this helps: contract mortal { /* ...READ MORE

Oct 22, 2018 in Blockchain by Omkar
• 69,180 points
2,008 views
0 votes
1 answer

How to install v1.7.3. of Geth using ppa?

The Ethereum PPA generally provides the latest ...READ MORE

Oct 17, 2018 in Blockchain by Christine
• 15,750 points
2,225 views
0 votes
2 answers

Ethereum function completed not event not showing up

Oh ya. I was passing unit but ...READ MORE

Oct 24, 2018 in Blockchain by slayer
• 29,370 points
1,879 views
0 votes
1 answer

Ethereum Mist: Compiling Error with sha3

First run: npm install sha3 and then sudo ...READ MORE

Oct 24, 2018 in Blockchain by Omkar
• 69,180 points
1,906 views
0 votes
1 answer

Hyperledger composer: network start gives no output

You are using -v as your option ...READ MORE

Nov 5, 2018 in Blockchain by Omkar
• 69,180 points
1,370 views
0 votes
1 answer

Historical ethereum prices - Coinbase API

def get_spot_price(self, **params): """https://developers.coinbase.com/api/v2#get-spot-price""" ...READ MORE

Sep 21, 2018 in Blockchain by digger
• 26,740 points
3,322 views
0 votes
1 answer

Are Ethereum contract function securable?

The reason is that you are using ...READ MORE

Oct 30, 2018 in Blockchain by Christine
• 15,750 points
1,730 views
0 votes
1 answer

Hyperledger Composer: How to save deployments?

You are losing your deployments probably because ...READ MORE

Oct 29, 2018 in Blockchain by Omkar
• 69,180 points
1,661 views
0 votes
1 answer

Hyperledger Fabric: ./byfn.sh -m up failed

Try adding GODEBUG=netdns=go to the environment variables ...READ MORE

Oct 26, 2018 in Blockchain by Omkar
• 69,180 points
1,758 views
0 votes
1 answer

Hyperledger Fabric : How to initialise a 2D array in .cto file?

You could try something like this, with ...READ MORE

Oct 30, 2018 in Blockchain by Omkar
• 69,180 points
1,574 views
0 votes
1 answer

Are there null like thing in solidity

You could create none variable to use it as ...READ MORE

Sep 21, 2018 in Blockchain by digger
• 26,740 points
3,235 views
0 votes
1 answer

Ethereum Advance token sample

Using > instead of >= is a ...READ MORE

Nov 2, 2018 in Blockchain by Christine
• 15,750 points
1,402 views
0 votes
1 answer

Hyperledger Composer cant find business card.

I changed the code to: var businessNetwork = ...READ MORE

Oct 26, 2018 in Blockchain by Omkar
• 69,180 points
1,686 views
0 votes
2 answers

How to check if bitcoin address is valid?

For Java, have a look at the ...READ MORE

Aug 20, 2018 in Blockchain by Omkar
• 69,180 points
4,535 views
0 votes
1 answer

Cant query in Hyperledger Composer

There's a mistake in your WHERE statement. ...READ MORE

Oct 26, 2018 in Blockchain by Omkar
• 69,180 points
1,682 views
0 votes
1 answer

Error when trying to deploy Ethereum smart contract using web3j

Create a new credential based on the Credentials.create ...READ MORE

Oct 3, 2018 in Blockchain by slayer
• 29,370 points
2,672 views
0 votes
1 answer

Test ethereum Event Logs with truffle

You are passing tx hash into done() ...READ MORE

Sep 21, 2018 in Blockchain by slayer
• 29,370 points
3,164 views
0 votes
1 answer

Hyperledger Composer: Error trying to instantiate composer runtime.

It looks like a problem with composer-cli.  A ...READ MORE

Oct 26, 2018 in Blockchain by Omkar
• 69,180 points
1,647 views
0 votes
1 answer

How to fix browser/IERC20.sol:4:53: Warning: This declaration shadows an existing declaration

I believe the issue is the reuse ...READ MORE

Oct 1, 2018 in Blockchain by slayer
• 29,370 points
2,727 views
0 votes
1 answer

Hyperledger fabric: vagrant up in devenv fails

This is a problem with vagrant 1.9.3: You ...READ MORE

Oct 29, 2018 in Blockchain by Omkar
• 69,180 points
1,515 views
0 votes
1 answer

Is the msg.sender address changed while passing to another contract as a parameter?

I tried your contracts in Remix, but ...READ MORE

Oct 10, 2018 in Blockchain by Omkar
• 69,180 points
2,327 views
0 votes
3 answers

UnhandledPromiseRejectionWarning: Error: The contract code couldn't be stored, please check your gas limit

I believe bytecode is being treated as ...READ MORE

Sep 24, 2018 in Blockchain by Teja
2,933 views
0 votes
1 answer

Docker on mac error message can't connect to Docker endpoint

While CORE_VM_ENDPOINT set to unix:///var/run/docker.sock, please make ...READ MORE

Sep 19, 2018 in Blockchain by slayer
• 29,370 points
3,225 views
0 votes
1 answer

Integrating web3 in cloud functions module

I had this issue and my problem ...READ MORE

Oct 17, 2018 in Blockchain by Perry
• 17,100 points
1,991 views
0 votes
1 answer

How to read the ETH value and other token values from an account?

You can do this eth.accounts shows you all known ...READ MORE

Oct 22, 2018 in Blockchain by Omkar
• 69,180 points
1,759 views
0 votes
1 answer

Unable to change a state variable in a contract

I am assuming that the issue is ...READ MORE

Oct 30, 2018 in Blockchain by Christine
• 15,750 points
1,443 views
+1 vote
3 answers

Pass all .dat files in folder to function

os.listdir(path) return names, not fullpaths change parseBlockFile(file) to fullpath = os.path.join(path,file) if os.path.isfile(fullpath) ...READ MORE

Sep 5, 2018 in Blockchain by Saygum
3,677 views
0 votes
1 answer

How to define the path to hyperledger-fabric chaincode?

You can find that in docker-compose files ...READ MORE

Oct 4, 2018 in Blockchain by Perry
• 17,100 points
2,506 views
0 votes
1 answer

re hyperledger's node/sdk: there is no typing definition( index.d.ts )

Looks like a bug in that the ...READ MORE

Oct 23, 2018 in Blockchain by Perry
• 17,100 points
1,668 views
0 votes
1 answer

How can I deploy a hyperledger business network using docker-compose?

If you want to use Composer, be ...READ MORE

Oct 4, 2018 in Blockchain by Perry
• 17,100 points
2,472 views
0 votes
1 answer

Nodejs cannot access Hyperledger composer shows error

1) you need Node 8.9.x or higher ...READ MORE

Oct 23, 2018 in Blockchain by Perry
• 17,100 points
1,641 views
0 votes
1 answer

403 forbidden error coinbase api

I had a similiar issue connecting this API, ...READ MORE

Aug 28, 2018 in Blockchain by digger
• 26,740 points
4,064 views
+6 votes
3 answers

Why don't we consider Git as a Blockchain?

Blockchain is not just any chain of any blocks. Blockchain is when there ...READ MORE

Sep 7, 2018 in Blockchain by Rowski
5,164 views
0 votes
1 answer

How to Query hdfs with Spark Sql

Yyou can achieve this by creating Dataframe. val ...READ MORE

Sep 20, 2018 in Blockchain by slayer
• 29,370 points
3,058 views
+1 vote
1 answer

Using bccsp instance from chaincode

You can take a look at this code snippet. ...READ MORE

Oct 22, 2018 in Blockchain by Christine
• 15,750 points
1,629 views
0 votes
1 answer

Is it possible to send eth to a contract through its constructor from another contract?

I found the solution for this: pragma solidity ...READ MORE

Sep 26, 2018 in Blockchain by slayer
• 29,370 points
2,778 views
0 votes
1 answer

pubToAddress method from ethereumjs-util throws AssertionError: false == true

This code works fine: var keythereum = require('keythereum'); var ...READ MORE

Oct 8, 2018 in Blockchain by Omkar
• 69,180 points
2,238 views
0 votes
1 answer

How do I send ether from an EOA to a smart contract?

You include ether to send in the ...READ MORE

Sep 27, 2018 in Blockchain by digger
• 26,740 points
2,710 views