Marco Ottolini
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1 answers
2 votes
2k views
How to turn off specific warnings for the solidity compiler?
3 votes

Even if "silencing warnings" has been debated for a long time (https://github.com/ethereum/solidity/issues/2691 and https://github.com/ethereum/solidity/issues/2675), it is not yet possible to do it. ...

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3 answers
1 votes
2k views
How to use web3 in a mobile context (ionic)?
1 votes

In case you are looking for a generic ethereum client implemented with Ionic, I released a simple POC on Github: https://github.com/mottolini/ionic-ethereum

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3 answers
0 votes
332 views
What are my blockchain options when I have terabytes of data to access?
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1 votes

Storing terabytes on the blockchain is not possible: it would cost too much. You have to store that data off-chain and eventually group it in a way that makes sense. What I did in a scenario similar ...

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1 answers
0 votes
1k views
How to enable/disable token transfer?
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1 votes

The contract IcoToken inherits Pausable so you can just call the function pause() to stop any activity among token holders. Total tokens sold are held in the totalSupply variable of the ICO contract: ...

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2 answers
0 votes
71 views
How to call a function of a smart contract
1 votes

Go to http://remix.ethereum.org (Ethereum Solidity IDE in a browser) and: click on the + at the top left Copy and paste your code in the main window Click un "run" tab Select "JavaScript VM" for the ...

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1 answers
0 votes
61 views
Ideal Blockchain decentralized app
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1 votes

I had a similar "problem" and the architecture I decide to use is a 3 tier one: client, private blockchain based on ethereum and a backend system for off-chain data. The client (in my case is a ...

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1 answers
0 votes
342 views
Assembly call instruction address as single integer
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1 votes

It refers to pre-compiled contracts. 6 refers to a the bn256Add pre-compiled contract in the Byzantium release. You should look for PrecompiledContractsByzantium in the geth source code to find a list ...

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1 answers
-5 votes
172 views
Need help integrating ERC20 on Exchange
1 votes

ERC20 is a standard that exposes some functions you can use directly without having access to the ABI. The only thing you need is the address of the ERC20 contract. I deployed two ERC20 contracts on ...

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2 answers
2 votes
311 views
Payable function not being called when ether is sent to the contract address
1 votes

Don't really understand what your problem is, but probably is not in the invocation of the fallback function. If you try to deploy the following contract, whichever function you call (buy, fallback ...

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1 answers
0 votes
11 views
How to create an infrastructure for node endpoint resolution on a multi-node network
0 votes

Never used it, but this seems promising: https://github.com/emeraldpay/dshackle

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4 answers
7 votes
3k views
Remix now force to use https, how can i continue to use http://remix.ethereum.org?
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To solve my problem I used a quick and dirty solution, similar to the trick used in hellopeach answer but doesn't provide you the remix interface. set up a virtual local server on port 80 for remix....

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2 answers
0 votes
1k views
How can I build this list of addresses
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You should simply declare an array and save the address of the sender in it: address[] private investorsList; function invest() public payable { require(msg.value == 0.1 ether); investorsList....

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3 answers
1 votes
724 views
Undeclared identifier onlyowner
0 votes

It seems your environment didn't import correctly the OpenZeppelin contracts. Try to change the references to the OpenZeppelin contracts to get the raw source code. Here are the addresses you should ...

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1 answers
1 votes
105 views
Accessing the Ethereum State Variables using web3js (Java Script)
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Execution of the web3js call is asynchronous, so "After Call" is executed before the code inside the loop. Try this: var coreValues = ['Apple', 'Banana']; console.log("Before call :" + coreValues[1]...

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2 answers
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117 views
What is the max data and program complexity one smart-contract can support
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What I normally use in cases like these is a "master" contract whose owner is the platform and deploys a separate contract for each "detail" contract. In your case, my suggestion is to have each bid ...

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2 answers
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88 views
Blockchain app technical architecture
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I implemented a private blockchain with a backend system in nodejs that handles some of the hurdles but left the blockchain doing the work is best at: giving trust. So, basically I implemented a ...

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1 answers
1 votes
122 views
Hiding values from calculation (zkSnarks?)
0 votes

Short answer is Yes, but depends on what you really need. The following contract stores the age of the person and without revealing it, can "certify" if the person is a teen or an adult. You can also ...

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