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contract reading array from other contract

There are two contracts in my project: admin groups voting Admin groups contain mapping(uint => address[]) internal m_Admins For example [1][0] = admin #1 with level 1 [9][0] = admin #2 with ...
1
vote
1answer
10 views

Creating an ERC20 Token on Rinkeby - Can't get the right supply

I'm creating an ERC20 token on Remix and using EIP20.sol from Consensys. I'm using this video tutorial as a guide - https://www.youtube.com/watch?v=d5EipPVafsA It's been helpful, however I have one ...
0
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0answers
18 views

Smart-contracts referencing each other [duplicate]

How would one retrieve these three addresses in the "Knot" smart-contract? I am very new to this, and would like to know whether this is even possible. The "Knot" contract should be able to reference ...
0
votes
1answer
52 views

Failed to load events from Block 0 on page refresh in Vue app

I'm trying to get event data from the web3 API using events method. In my Vue app methods, I have a method, newDsoValue, that will watch for the events from the beginning and also for every newly ...
0
votes
1answer
16 views

Cannot install remix-ide locally

How to install remix-ide npm module? I follow the instructions, but it does not install. npm install remix-ide -g ... make: *** [Release/obj.target/scrypt/src/node-boilerplate/scrypt_params_async.o] ...
-2
votes
1answer
24 views

TypeError: No matching declaration found after argument-dependent lookup

ERROR:TypeError: No matching declaration found after argument-dependent lookup.require (positionIsInBounds(xpos,ypos)); ^-----^ pragma solidity ^0.5.1; contract TicTacToe { //addresses of ...
1
vote
1answer
20 views

Implementing a state channel

I am trying to build a platform to play TicTacToe using DApps. The players invite others by placing a stake and then opponents accept it. The first turn is recorded on chain by calling a function in ...
2
votes
1answer
17 views

Etherescan Unique Address Growth Chart - How is it computed?

how does Etherscan get this information from the blockchain? Is it possible via using a web3 module? Any insight? https://etherscan.io/chart/address
2
votes
1answer
27 views

Kaleido private network transaction exited with an error (status 0) after consuming all gas

I've created a private PoA network with two geth nodes using Kaleido (release 1.0.13) and am trying to deploy some smart contracts to it using the drizzle-kaleido-box boilerplate from truffle. The ...
1
vote
0answers
11 views

All contract calls returning null

I'm building a browser extension that uses web3.js over websocket to Infura and for some reason all my contract calls are returning null in my production build. When testing the app as a web app in ...
0
votes
1answer
29 views

Pushing A Struct Instance Into An Struct Array Of A Different Struct Mapping

How can I push a struct instance into a mapping which contains a distinct struct which contains a struct array of the attempted struct instance type? Example: contract NewBook { struct ...
1
vote
1answer
19 views

truffle migrate --network kovan issue

When I run truffle migrate --network kovan in the terminal the contract deployment doesn't run. Just: Compiling your contracts...==================== >Eveything is up to date, there is nothing to ...
1
vote
1answer
21 views

company using IPFS in their application

I am learning IPFS these days and curious about if any company is using IPFS to save data. When we upload file into IPFS, we get a hash and can use the hash to get access to the file content. But in ...
0
votes
1answer
18 views

Return an array of structs using events?

I wan’t my function to spit out an array of structs. I know this is not straightforwardly possible. What is the best way for me to proceed? Should I loop through my array in my function and trigger ...
0
votes
1answer
31 views

Mapping Multiple Struct Instances To One Address

How can I map multiple struct instances to one user without overriding the previous instance? I want to retrieve both instances through one mapping query. Should I use a multi-dimensional array here ...
1
vote
1answer
32 views

Solidity: Raise events via Assembly using log3

I want to raise events from inside a piece of assembly code. I've extended the answer here with the function AssemblyEvent() which currently causes a runtime error. Working example: pragma ...
2
votes
1answer
28 views

Convert BIP-39 mnemonic to Ethereum private key in Python

How do I convert a BIP-39 mnemonic to an Ethereum private key in Python (via BIP-44 key derivation)? All the libraries I found that gave me the intended result depend on the two1 package, which ...
0
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0answers
22 views

Unconfirmed ethereum transaction without nonce and transaction hash

Hello I’m a newbie here I need help. It’s almost 24 hours I send ethereum it is still not confirmed and it has not been deducted from my blockchain wallet. It does not show in the transaction record ...
0
votes
1answer
15 views

is it possible to use IPFS Hash to ensure file integrity?

My question is if i can use the IPFS Reference/Hash to ensure file integrity. In other words if i have a file can i use a specific Hashfunction to ensure that the generated Hash of that file is equal ...
0
votes
1answer
21 views

Incorrect Usage. flag provided but not defined: -emitcheckpoints

I'am trying to build this : PRIVATE_CONFIG=ignore nohup geth --datadir ./Node1/new- node-1 --nodiscover --verbosity 5 --networkid 31337 -- rpccorsdomain="*" --ws --wsorigins="*" --...
0
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0answers
48 views

Error when testing the contract

ApprovalContract.sol pragma solidity ^0.5.1; contract ApprovalContract{ address public sender; address payable public reciever; address public constant approver=...
0
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0answers
17 views

How to attach a Logo to an ERC20 Token

I have created an ERC20 Token with MEW. However, when I send it to people who have different ERC20 wallets, the logo of my token is always Ethereum like How do I put my own logo on the token so that ...
0
votes
2answers
20 views

Does price of smart contract execution raise with price of ethereum

I can't determine properly whether higher price of ETH means smart contracts will also cost higher(in fiat not eth) and is it reciprocal, like if we have a SC deployed and eth price raises 10x, will ...
1
vote
0answers
9 views

What are the rules on persisting old transactions?

If a new node joins the network and attempts a full sync, it requires all transaction information from genesis to build up its chain state. To do this the transactions it receives must be the ...
0
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0answers
42 views

What is the standard practice for ETH seed - 12 or 24 words?

Afaik for BTC a 12-word seed is considered secure because it utilizes 128 bits of entropy, which is the same as for BTC private keys. Is 12 words same good for ETH? What is the current standard the ...
0
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0answers
28 views

uncaught error:invalid address

Uncaught (in promise) Error: invalid address at inputAddressFormatter (formatters.js:271) at inputTransactionFormatter (formatters.js:97) at method.js:89 at Array.map (<anonymous>...
0
votes
1answer
20 views

Issue with Serverless deploy of smart contract-Dependency mismatch -Package.json,Package-lock.json error

I'm trying to deploy my smart contract serverless(AWS lambda) and I'm using Truffle framework. The code is getting deployed in an earlier system(earlier it was deployed here). Now I have updated the ...
0
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0answers
12 views

how to verify details put by a person through smart contract? [closed]

Iam working on a developing a tool that should verify details provided by the individual. let's say if a person says he works in a XYZ company and he want to add to his resume. That XYZ company ...
0
votes
0answers
16 views

Contract cannot create new Contract in Quorum

My main contract called SurveyFactory creates new Survey forms: pragma solidity = 0.5.9; import './Survey.sol'; contract SurveyFactory { address[] public surveyList; address public Owner; ...
1
vote
1answer
24 views

What is the benefit of leaving data in the stroage area instead of the log?

I did not write English well and used a translator. sorry :3 I would like to know the benefit of leaving data in the storage area rather than using the event log. I know gas consumption has less log....
1
vote
0answers
16 views

MAC OSX geth console error

I have installed Geth on my mac Mojave 10.14.3 by brew tap ethereum/ethereum and brew install ethereum Just the same as the instruction and everything goes well, but when I run geth console ...
3
votes
1answer
88 views

Is it possible to hard fork a private network to Constantinople?

I have a Proof-of-Authority private Ethereum network that has Byzantium EVM version and created by clique engine. I have a single miner that has Geth version: v1.8.27. { "config": { "chainId": ...
0
votes
1answer
27 views

Auto-Response smart contract [on hold]

I would like to make a smart contract that can auto-respond.. Something like an email auto-responder. A user sends a transaction with a message to the smart contract, and if that message is ' True' , ...
0
votes
1answer
25 views

What should gas prices be for sending out tokens?

I constantly get failed transactions when sending out tokens like USDT using metamask. I have my gwei set at 10 and the gas limit at 21000. I even tried gas limit set to 51000 and it still fails. ...
1
vote
0answers
23 views

Cannot read property 'type' of undefined - abi-coder

I'm creating a simple voting contract. It is deployed with truffle and infura. This is the contract code: pragma solidity >=0.4.21 <0.6.0; contract Voter { struct OptionPos { uint ...
1
vote
1answer
31 views

Random Group Generation From Array

How can I form a random group of 5 people from an array of 100 people?
2
votes
0answers
24 views

How shoud I properly initialize DApp and get account address?

I am writing DApp in react, and basically I want to initialize web3, unlock account, and display it. Having web3 in my package.json In the onload I've tried to go following: let Web3 = require('web3')...
2
votes
1answer
72 views

0x0000000000000000000000000000000000000000 address behaviour

I have a question about the possibly strange behaviours of address: 0x0000000000000000000000000000000000000000 We know that: ETH + ERC20 tokens sent there are burnt Upon creation of a new smart ...
1
vote
0answers
14 views

syncing is never finish on geth fast

I have run geth --fast --cache=4000 for 8 days and I think I am almost complete: eth.syncing { currentBlock: 8123223, highestBlock: 8123315, knownStates: 309587058, pulledStates: ...
0
votes
0answers
14 views

Getting TxnHash but not recipt web3j android

I dont know if question is asked before but I did not find any. I am facing this issue since yesterday. I am able to get balance and txnHash but it never shows on etherScan.io , nor it gives me txn. ...
0
votes
0answers
17 views

How to use the ipfs.get()?

I am new to IPFS. I added a file in IPFS and then, pinned it. Now, I am trying to retrieve the file. I am writing the code in React. Hence I used the following code: ipfs.get('/ipfs/...
0
votes
0answers
10 views

geth: How to change the path to create `private` folder

In general, private folder used to created under the main directory now by default, on geth v1.8.27, it is created under the root directory and there is a already default /private folder on Mac. [Q] ...
-1
votes
0answers
14 views

please help with this error- Error: Returned values aren't valid, did it run Out of Gas? [closed]

const assert = require('assert'); const ganache = require('ganache-cli'); const Web3 = require('web3'); const provider=ganache.provider(); const web3 = new Web3(ganache.provider()); const {interface,...
-1
votes
0answers
19 views

Gas estimation errored . The transaction execution will likely fail. gas required exceeds allowance (7043640) or always failing transaction on rinkeby

I'm getting this error when I call the this function in my smart contract deployed to rinkeby testnet. function createToken(string _name, address _owner, uint256 _price) public onlyCLevel { ...
1
vote
0answers
13 views

I want to make multi-node , not private network

I know how to make multi-node in private network, but I have a question how to make a multi-node with other machines. this picture shows independent two nodes, and you can see blank on admin.peers ...
1
vote
0answers
18 views

Invalid Private Key Format

Apologies in advance if this is a silly question but I can't figure out why my metamask private key is 66 characters long instead of 64? I'm attempting to use this key with the MakerDao Dai.js library ...
0
votes
0answers
16 views

What's the best way to detect an incoming transaction with websockets and update balance?

What's the best way to detect an incoming transaction with web sockets and update balance? Should it be done with polling? Like for example - how would a web wallet do it? It's sitting idle - is it ...
1
vote
1answer
21 views

RLP decoding for a list

in many standard documentation and many blogs, I have found the example for list with two strings like below [“cat”, “dog” ] -> C8 83 636174 83 646F67 and thats how it is decoded 1) Retrieve the ...
0
votes
0answers
17 views

Does value of v represent that coordinate y of (deterministic k * G) is even or odd in Ehereum?

I'm quite confused about whether value v is related to deterministic k derived from RFC6979. I know that we can try 4 possibilities of v and compare to public key. And if (lower r, y is even), then ...
1
vote
1answer
13 views

Scope Issue: Not successfully storing accounts after using web3.eth.getAccounts()

I am having trouble with the following code: var accounts = [] let accounts = await web3.eth.getAccounts((error, result) => { accounts = result; console.log(accounts); }); console.log(...

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