These are chat archives for ethereum/tutorials

Apr 2016
Daniel Spiteri
Apr 29 2016 04:12
hello Everyone ! ;)
Makoto Inoue
Apr 29 2016 08:42

Good morning. I have a noob question. Is there any way for Solidity to restrict amount of value to be sent? For example in the token example,

function buy() returns (uint amount){
    amount = msg.value / buyPrice;                     // calculates the amount
    if (balanceOf[this] < amount) throw;               // checks if it has enough to sell
    balanceOf[msg.sender] += amount;                   // adds the amount to buyer's balance
    balanceOf[this] -= amount;                         // subtracts amount from seller's balance
    Transfer(this, msg.sender, amount);                // execute an event reflecting the change
    return amount;                                     // ends function and returns

buy() function is only checking the balance of the contract itself, but not limiting the amount of msg.value. Though I can control how much to send at Javascript level, are there any way to gurantee the amount you can send per transaction at contract level?

Alex Van de Sande
Apr 29 2016 09:35
@makoto sure
`if (msg.value > maxValue) throw'
Makoto Inoue
Apr 29 2016 12:32
@alexvandesande thanks