I am new to the dApp development. I want to deploy a contract to Ethereum through a website i am building. However i don't want the user to do it through the solidity online compiler or mist wallet. I want the user to press a button and the contract to automatically deploy on the Ethereum (backend function). I am using meteor for this project. Any suggestions on how to implement something like that? Thank you
Can you run this in Geth console?
> var source = "contract demo { string public name = 'Petros'; function changeName(string _newName){ name = _newName; }}";
> var compiled = web3.eth.compile.solidity(source);
> web3.eth.compile.solidity(source, function(err, res) { console.log(JSON.stringify(res)); });
The ABI will be compiled.demo.info.abiDefinition.
If you make an asynchronous call in Javascript, then what you get is in the callback, it is not in the returned thingy.
So this does not work:
var thisWillBeUndefinedObviously = web3.eth.compile.solidity(source, function(err, res) { console.log(JSON.stringify(res)); });
answered Jan 31 '17 at 22:41
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Ok so my return would be console.log(JSON.stringify(res)) from the callback function got it. However it doesn't show anywhere the contract address or abi so i can retrieve my string later. Also i wasn't using geth. deployed a couple of contracts through mist and solidity-metamask. I downloaded it, first command you told me to run was undefined and the second is still syncing the blockchain – PetrosM Feb 1 '17 at 11:38
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I edited my answer to tell you where is the ABI you missed. Compilation is one step. After, you need to deploy your contract, which gives you an address. The commands I gave you return undefined because they create variables. Call these variables to see what they have. Javascript 101. When you deployed through Mist, it did compile and deploy in 1 step. – Xavier Leprêtre B9lab Feb 1 '17 at 16:56
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var source = "" + "contract demo {\n" + " string public name = 'Petros';\n" + " function changeName(string _newName){\n" + " name = _newName;\n" + " }\n" + "}\n"; var compiled = web3.eth.compile.solidity(source, function(err,res){ //necessary callback function console.log(compiled); }); console.log(compiled);However the code doesn't appear to compile and nothing shows in the console – PetrosM Jan 31 '17 at 16:41console.log(compiled)if it isresthat you get? – Xavier Leprêtre B9lab Jan 31 '17 at 17:10console.log(res)which does return an object with too many options that i don't understand. However there is still the problem thatconsole.log(compiled);in the end won't return anything. I can't find a way to interact to interact with the returnedresobject. i.e. how can i retrieve the string "petros" from the contract i deployed? – PetrosM Jan 31 '17 at 19:57