Trending questions in Blockchain

0 votes
1 answer

Hyperledger Composer: Failed to load connector module “composer-connector-undefined” for connection type “undefined”

Hey. First, make sure that you are extending ...READ MORE

Oct 30, 2018 in Blockchain by Omkar
• 69,180 points
• 2,384 views
0 votes
3 answers

python ethereum (pyethapp): Failed building wheel for scrypt.

First try installing sudo apt-get install openssl However, If ...READ MORE

Oct 12, 2018 in Blockchain by Girish
• 3,404 views
0 votes
1 answer

How to handle smart contract transaction express nodejs?

sendSignedTransaction returns a Promise combined event emitter. You can ...READ MORE

Oct 15, 2018 in Blockchain by Omkar
• 69,180 points
• 3,024 views
0 votes
1 answer

How to get TimeStamps in Hyperledger Composer?

Here's an example that works with basic-sample-network network: asset SampleAsset ...READ MORE

Oct 26, 2018 in Blockchain by Omkar
• 69,180 points
• 2,549 views
0 votes
1 answer

Hyperledger Fabric: peer creation no ordering service endpoint created error

You have to pass an orderer in ...READ MORE

Nov 15, 2018 in Blockchain by Omkar
• 69,180 points
• 1,660 views
0 votes
1 answer

var_dump of a JSON response returns NULL

You should be aware of the chances ...READ MORE

Aug 28, 2018 in Blockchain by digger
• 26,740 points
• 5,068 views
0 votes
1 answer

Hyperledger: How to retrieve properties of relationship through query?

I dont think its possible using query. ...READ MORE

Nov 8, 2018 in Blockchain by Omkar
• 69,180 points
• 1,958 views
0 votes
1 answer

How can I send data to docker?

Whenever i invoke chaincode from the cli ...READ MORE

Nov 17, 2018 in Blockchain by Christine
• 15,750 points
• 1,598 views
0 votes
1 answer

Hyperledger Fabric: Cant create channel on peer

Add host entries to your /etc/hosts should resolve your ...READ MORE

Oct 26, 2018 in Blockchain by Omkar
• 69,180 points
• 2,510 views
0 votes
1 answer

Stuck while using call_back_address and ipn url in coinpayment.net gateway

To make use of this api, just ...READ MORE

Aug 31, 2018 in Blockchain by digger
• 26,740 points
• 4,899 views
0 votes
1 answer

Access multiple return values (a, b, c) from solidity function in web3js

You'll get an array of return values ...READ MORE

Sep 14, 2018 in Blockchain by slayer
• 29,370 points
• 4,287 views
0 votes
1 answer

Hyperledger Composer: Query using relation

 you need to refer to your specific ...READ MORE

Nov 5, 2018 in Blockchain by Omkar
• 69,180 points
• 2,026 views
0 votes
1 answer

Hyperledger Composer: REST Server transaction failed but returns 200 status

You need to return the function calls from the ...READ MORE

Nov 6, 2018 in Blockchain by Omkar
• 69,180 points
• 1,982 views
0 votes
1 answer

Ethereum call contract method that emits an event, from another contract

You need to refer to the EventEmitter by ...READ MORE

Sep 25, 2018 in Blockchain by digger
• 26,740 points
• 3,783 views
0 votes
1 answer

Get specific JSON data value using array from Coin Market Cap API

use inArray function. example: $.getJSON("//api.coinmarketcap.com/v1/ticker/?limit=0", function(data) { ...READ MORE

Oct 8, 2018 in Blockchain by Omkar
• 69,180 points
• 3,220 views
0 votes
1 answer

Hyperledger Fabric v1.0 setup on multiple machines

You would be able to host hyperledger fabric ...READ MORE

Oct 23, 2018 in Blockchain by Perry
• 17,100 points
• 2,546 views
0 votes
1 answer

What is the default network that truffle migrates to when the config has 2 networks?

If --network is unspecified, it deploys to only development. You ...READ MORE

Oct 15, 2018 in Blockchain by Omkar
• 69,180 points
• 2,895 views
0 votes
1 answer

Invalid method parameters for eth_sendTransaction

params needs to be an array, try {"jsonrpc":"2.0","method":"eth_se ...READ MORE

Sep 28, 2018 in Blockchain by digger
• 26,740 points
• 3,618 views
0 votes
1 answer

Intrinsic gas too low and exceeds block limit

If you are talking about the public ...READ MORE

Aug 29, 2018 in Blockchain by digger
• 26,740 points
• 4,901 views
0 votes
1 answer

Truffle migrate fails due to missing function, but it exists in node_modules

deployer.deploy(password1, password2, deadline, {value: 100, from: accounts[0]}); ...READ MORE

Oct 3, 2018 in Blockchain by digger
• 26,740 points
• 3,387 views
0 votes
1 answer

Hyperledger Composer: How to query using string?

You can try this: query selectReading { ...READ MORE

Nov 9, 2018 in Blockchain by Omkar
• 69,180 points
• 1,780 views
0 votes
2 answers

UnicodeDecodeError: 'utf-8' codec can't decode byte (python)

I found a python rpc library for ...READ MORE

Sep 4, 2018 in Blockchain by Piston
• 4,590 views
0 votes
1 answer

Hyperledger Fabric: Not able to install docker

Clean up the invalid package repository: cd ../../etc/apt/sources.list.d sudo ...READ MORE

Nov 2, 2018 in Blockchain by Omkar
• 69,180 points
• 2,062 views
+1 vote
3 answers

What is the pattern for handling throw on a Solidity contract in tests

In my opinion the cleanest way is: it("should ...READ MORE

Sep 25, 2018 in Blockchain by Lupin
• 3,603 views
+1 vote
1 answer

Can't instantiate any chaincodes on peers of newly Added org

Seems like chaincode install may have been unsuccessful. Before ...READ MORE

Sep 20, 2018 in Blockchain by Perry
• 17,100 points
• 3,878 views
0 votes
1 answer

Uncaught ReferenceError: web3 is not defined at window.onload

I think the onload is giving the issue. Try this ...READ MORE

Sep 28, 2018 in Blockchain by slayer
• 29,370 points
• 3,559 views
0 votes
1 answer

Ethereum client-go RPC response 403 “invalid host specified”

Adding --rpcvhosts=* should solve the issue READ MORE

Oct 1, 2018 in Blockchain by slayer
• 29,370 points
• 3,428 views
0 votes
1 answer

Hyperledger Composer: Not able to query fabric.

Add another rule to .acl file to ...READ MORE

Nov 12, 2018 in Blockchain by Omkar
• 69,180 points
• 1,603 views
0 votes
1 answer

Ethereum solidity: Unable to get value from another contract

I have faced similar issues when compiling ...READ MORE

Oct 15, 2018 in Blockchain by Omkar
• 69,180 points
• 2,806 views
0 votes
1 answer

Ethereum truffle MetaCoin : 'intrinsic gas too low' error

Change the genesis block gasLimit to "gasLimit": "0x2FEFD800", config ...READ MORE

Oct 22, 2018 in Blockchain by Omkar
• 69,180 points
• 2,501 views
0 votes
1 answer

Ethereum: functions Burn and Transfer source

This statement is used to publish an event that ...READ MORE

Oct 9, 2018 in Blockchain by Omkar
• 69,180 points
• 3,064 views
0 votes
1 answer

Hyperledger Farbic: Deploying business network definition

Try to clean everything using the below ...READ MORE

Nov 13, 2018 in Blockchain by Omkar
• 69,180 points
• 1,549 views
0 votes
1 answer

eth.getTransactionReceipt returns null

It looks like there's an issue with ...READ MORE

Sep 25, 2018 in Blockchain by slayer
• 29,370 points
• 3,661 views
0 votes
1 answer

Hyperledger fabcar: node enrollAdmin.js error

Update the node: npm rebuild and then run ...READ MORE

Oct 26, 2018 in Blockchain by anonymous
• 2,313 views
0 votes
1 answer

NodeJS POST Request Over JSON-RPC

You're missing the --header option: curl --request POST \ ...READ MORE

Sep 28, 2018 in Blockchain by digger
• 26,740 points
• 3,518 views
0 votes
1 answer

Cant get a specific value in JSON/PHP

Convert the json-string to a php-array and ...READ MORE

Sep 11, 2018 in Blockchain by slayer
• 29,370 points
• 4,225 views
0 votes
1 answer

How to efficiently hash (SHA 256) in golang data where only the last few bytes changes

You can try the following examples on ...READ MORE

Jun 27, 2018 in Blockchain by aryya
• 7,460 points
• 7,474 views
0 votes
1 answer

Web-scraping from Coinbase with Python (Pycharm)

Data that you want to scrape is ...READ MORE

Sep 4, 2018 in Blockchain by digger
• 26,740 points
• 4,496 views
0 votes
1 answer

Getting the length of public array variable (getter)

The calling contract will need the ABI ...READ MORE

Sep 24, 2018 in Blockchain by digger
• 26,740 points
• 3,631 views
0 votes
1 answer

Can I execute distributions in ERC20 tokens on a later stage?

It is best to have a claim ...READ MORE

Nov 2, 2018 in Blockchain by Prerna
• 1,960 points
• 1,934 views
0 votes
1 answer

Solidity: logical AND outputs parser error

Its Syntax error logical and operator is ...READ MORE

Oct 12, 2018 in Blockchain by Perry
• 17,100 points
• 2,830 views
0 votes
2 answers

Check Bitcoin Balance with mybitx api https GET url

You can use the PHP Requests library for an ...READ MORE

Sep 17, 2018 in Blockchain by Lalit
• 3,989 views
0 votes
1 answer

Setting up Hyperledger Fabric Application with IBM Cloud.

You have to develop your "Client" application ...READ MORE

Nov 6, 2018 in Blockchain by Perry
• 17,100 points
• 1,747 views
0 votes
1 answer

How to reduce a random hash to a boolean value

Take the largest or smallest bit from ...READ MORE

Oct 30, 2018 in Blockchain by Christine
• 15,750 points
• 2,149 views
0 votes
1 answer

Hyperledger fabric: Unable to query result

In Hyperledger Fabric v1.0.0 your chaincode should confirm ...READ MORE

Oct 30, 2018 in Blockchain by Omkar
• 69,180 points
• 2,054 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
• 3,728 views
0 votes
1 answer

Hyperledger fabric: curl not working to invoke chaincode

Hyperledger Fabric does not offer a REST ...READ MORE

Oct 23, 2018 in Blockchain by Perry
• 17,100 points
• 2,331 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
• 1,893 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
• 5,495 views
0 votes
1 answer

Etheruem: Unable to import library in Remix IDE

Your link is broken. This is the ...READ MORE

Oct 9, 2018 in Blockchain by Omkar
• 69,180 points
• 2,882 views