Trending questions in Blockchain

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Hyperledger Fabric ./byfn -m up not bringing up

Seems like you have not installed docker-compose. ...READ MORE

Nov 5, 2018 in Blockchain by Omkar
• 69,190 points
990 views
0 votes
1 answer

Hyperledger Fabric: cp: cannot stat ‘build/docker/gotools/bin/protoc-gen-go’: No such file or directory

Do this: $go get -u github.com/golang/protobuf/protoc-gen-go $ cp $GOPATH/bin/protoc-gen-go build/docker/gotools/bin/ Now ...READ MORE

Oct 29, 2018 in Blockchain by Omkar
• 69,190 points
1,289 views
+1 vote
1 answer

Error while instantiating chaincode

Hey @Vikas!  The error says, dial unix /host/var/run/docker.sock: connect: ...READ MORE

Nov 6, 2018 in Blockchain by Omkar
• 69,190 points
891 views
0 votes
1 answer

Invalid opcode error in a simple Solidity contract and script

You don't need to call .at() if you're using .new(). ...READ MORE

Sep 14, 2018 in Blockchain by slayer
• 29,350 points
3,228 views
0 votes
1 answer

Hyperledger Fabric: Changing component item owner automatically with its parent

You can try something like this: /** * ...READ MORE

Nov 16, 2018 in Blockchain by Omkar
• 69,190 points
499 views
0 votes
1 answer

Hyperledger Composer: Error: Object with ID 'assetID:0138' in collection with ID 'Asset:org.acme.mynetwork.Sensor'

Remove 'assetID:' from your test string. For example, 'org.acme.mynetwork#assetID:0138' ...READ MORE

Nov 14, 2018 in Blockchain by Omkar
• 69,190 points
585 views
0 votes
1 answer

Web3js: how to catch ethereum contract exception?

try this: try{ Test test = Test.load(contractObj.getContractAddress(), ...READ MORE

Oct 22, 2018 in Blockchain by Omkar
• 69,190 points
1,570 views
0 votes
1 answer

Ethereum Node Connection: TypeError: Cannot read property 'version' of undefined

In the code that you are using ...READ MORE

Oct 24, 2018 in Blockchain by Omkar
• 69,190 points
1,482 views
0 votes
1 answer

How to connect channels of different systems in Hyperledger Fabric?

When you create a channel, you will ...READ MORE

Nov 20, 2018 in Blockchain by Omkar
• 69,190 points
299 views
0 votes
1 answer

Hyperledger Composer: How to Update Existing Assets?

get on an asset registry returns a ...READ MORE

Nov 5, 2018 in Blockchain by Omkar
• 69,190 points
939 views
0 votes
1 answer

Hyperledger Composer: How to specify server name in composer connection profile?

To solve this problem you can use ...READ MORE

Nov 14, 2018 in Blockchain by Omkar
• 69,190 points
561 views
0 votes
1 answer

What files are supported by BigchainDB?

BigchainDB supports .json file format. It can ...READ MORE

Feb 26, 2019 in Blockchain by anonymous
313 views
0 votes
1 answer

Hyperledger Fabric: Could not resolve all dependencies for configuration

First, build the chaincode using gradle build. You should ...READ MORE

Nov 2, 2018 in Blockchain by Omkar
• 69,190 points
1,070 views
0 votes
1 answer

Hyperledger Fabric: How to ping network using program?

// http://nodejs.org/api.html#_child_processes var sys = require('sys') var exec = ...READ MORE

Nov 9, 2018 in Blockchain by Omkar
• 69,190 points
722 views
0 votes
1 answer

Hyperledger Fabric: Cannot update chaincode

First, stop and delete all the containers: docker ...READ MORE

Oct 31, 2018 in Blockchain by Omkar
• 69,190 points
1,091 views
0 votes
1 answer

Can't call contract function in truffle console

Inspect the object adoption within the console. You will ...READ MORE

Sep 28, 2018 in Blockchain by slayer
• 29,350 points
2,503 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
• 69,190 points
418 views
0 votes
1 answer

Hyperledger Fabric: Error: Error getting (myc) orderer endpoint: Error endorsing GetConfigBlock

First of all please note, that during ...READ MORE

Oct 31, 2018 in Blockchain by Omkar
• 69,190 points
1,056 views
0 votes
3 answers

String conversion to Array in Solidity

There is no built-in method/function for this ...READ MORE

Oct 3, 2018 in Blockchain by Charlie
2,351 views
0 votes
1 answer

Hyperledger Composer: not able to install Hyperledger composer-cli

Try setting the PATH like this, export PATH="/usr/local/share/npm/bin:$PATH" Now run the ...READ MORE

Oct 31, 2018 in Blockchain by Omkar
• 69,190 points
1,048 views
0 votes
1 answer

String concatenation in solidity?

A library can be used, for example: import "github.com/Arachnid/solidity-stringutils/strings.sol"; contract C ...READ MORE

Sep 21, 2018 in Blockchain by slayer
• 29,350 points
2,770 views
0 votes
1 answer

Hyperledger composer: runtime install error card not found peerAdmin

The right way to do it is: downloadFabric.sh startFabric.sh createPeerAdminCard.sh If ...READ MORE

Nov 5, 2018 in Blockchain by Omkar
• 69,190 points
791 views
0 votes
1 answer

How to get return value from solidity contract?

Once you call a constant function, you ...READ MORE

Aug 16, 2018 in Blockchain by slayer
• 29,350 points
4,302 views
0 votes
1 answer

Hyperledger Fabric: error on outputChannelCreateTx: Cannot define a new channel with no Application section

Try defining or referencing the application in ...READ MORE

Nov 2, 2018 in Blockchain by Omkar
• 69,190 points
901 views
0 votes
1 answer

Error With Rest Server: HyperLedger

It's a trivial issue mate - you're ...READ MORE

Nov 9, 2018 in Blockchain by Christine
• 15,790 points
567 views
0 votes
1 answer

Using json rpc with curl on java?

Quoting different pieces the way you're doing ...READ MORE

Oct 10, 2018 in Blockchain by Omkar
• 69,190 points
1,870 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
• 15,790 points
254 views
0 votes
1 answer

Hyperledger composer: How to allow create in transaction? Access Control

This is how you can do it: /** @returns ...READ MORE

Nov 8, 2018 in Blockchain by Omkar
• 69,190 points
578 views
0 votes
1 answer

Hyperledger Fabric: unable to check out source code from gerrit.hyperledger.org

There's something wrong with your SSH key. ...READ MORE

Nov 15, 2018 in Blockchain by Omkar
• 69,190 points
269 views
0 votes
1 answer

Getting “web3.eth.filter is not a function” while trying to monitor Ethereum blocks

It appears you are using web3.js v1.0. ...READ MORE

Oct 9, 2018 in Blockchain by Omkar
• 69,190 points
1,852 views
0 votes
1 answer

Javascript Websocket subscribe to channel

This is how you can do it let ...READ MORE

Aug 28, 2018 in Blockchain by slayer
• 29,350 points
3,637 views
0 votes
1 answer

Hyperledger Fabric: How to convert channel.tx artifact into json?

You can use configtxgen to do this: configtxgen ...READ MORE

Nov 8, 2018 in Blockchain by Omkar
• 69,190 points
509 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
• 69,190 points
619 views
0 votes
1 answer

PHP IPC with geth Ethereum: How to communicate with client?

You have to use PHP Sockets $sock = socket_create(AF_UNIX, ...READ MORE

Oct 22, 2018 in Blockchain by Omkar
• 69,190 points
1,230 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
• 69,190 points
493 views
0 votes
1 answer

Hyperledger: Not able to connect from docker container to validator. curl http://rest-api:8008/blocks

The REST API service is exposed on ...READ MORE

Nov 2, 2018 in Blockchain by Omkar
• 69,190 points
748 views
0 votes
1 answer

Truffle Compile failing, ParserError: Expected token LParen got Identifier function

Your parentheses are mismatched. pragma solidity ^0.4.17; import "truffle/Assert.sol"; import ...READ MORE

Oct 9, 2018 in Blockchain by Omkar
• 69,190 points
1,785 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
• 69,190 points
295 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
• 69,190 points
249 views
0 votes
1 answer

Docker: How to connect Node.js in container to Hyperledger Fabric?

You need to map ~/.composer/cards of your Docker host ...READ MORE

Oct 31, 2018 in Blockchain by Omkar
• 69,190 points
794 views
0 votes
1 answer

How do I initialize an array in a struct

You need to manually change the length ...READ MORE

Oct 1, 2018 in Blockchain by Perry
• 17,100 points
2,073 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
• 69,190 points
1,463 views
0 votes
1 answer

Web3: No provider set error

To solve this error, you need to ...READ MORE

Oct 22, 2018 in Blockchain by Omkar
• 69,190 points
1,158 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
• 69,190 points
493 views
+4 votes
2 answers

Warning: Invoking events without “emit” prefix is deprecated while truffle compile

As the warning mentions, add emit as ...READ MORE

Oct 16, 2018 in Blockchain by Aisha
1,211 views
0 votes
1 answer

Hyperledger Composer: How to update a contract after it is saved?

Try this and see if this works: /** * ...READ MORE

Nov 9, 2018 in Blockchain by Omkar
• 69,190 points
352 views
0 votes
1 answer

How to make Observable from callback?

RxJS includes a bindNodeCallback observable creator specifically for creating ...READ MORE

Oct 1, 2018 in Blockchain by digger
• 26,740 points
2,016 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
• 69,190 points
921 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
1,030 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
422 views