Questions tagged [smart-contract]
Anything related to decentralized application (dApp) development, concepts, and possibilities with smart contracts, or technical questions for the development of smart contracts.
618
questions
1
vote
0
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36
views
No tables in abi file
I am trying to write a smart contract but for some reason my tables aren't being added to the abi file and therefore aren't being added to the blockchain.
My code is as follows. Am I possibly ...
- 131
0
votes
1
answer
82
views
Is there any API in EOS Smart Contract to decrypt message? [duplicate]
I would like to create a smart contract that would be able to decrypt some symmetrically encrypted message.
Here is the scenario:
Party "A" sends a message encrypted with key "123456" to ...
- 147
1
vote
1
answer
288
views
Broadcast Smart Contract 'Hello World' error
I am going through the eos tutorial but I got stuck at the contract broadcast.
When I compile the contract with eosio-cpp -o hello.wasm hello.cpp --abigen the console seems to get stuck and I have ...
- 11
0
votes
2
answers
79
views
Transaction took too long while using std::shuffle
Get the error when I push a action on my contract on the local testnet:
But if I remove this code from the action I called, there is no problem:
class urng:
Does anyone know what caused this?I just ...
- 3
5
votes
1
answer
580
views
What could be the reason for 'Error 3050008: Abort Called'
I'm getting the following error without any further description. What could be the issue for that?
I'm performing some binary arithmetics when calling this action, are there any known problems with ...
- 1,929
6
votes
2
answers
2k
views
How to use checksum256 secondary index to get table rows
Does anyone know the correct way to get table rows using checksum256 (fixed_bytes<32>) secondary index through the get_table_rows RPC API?
I found a way using key256, but key256 is deprecated ...
- 61
0
votes
2
answers
178
views
require_auth() not working as expected
I adapted the hello contract, expanding with require_auth() and added an additional account oliver that should be able to execute the action hashin on behalf of the contract owner doctest1. I adjusted ...
- 1
5
votes
2
answers
2k
views
How to get current time in different versions of EOSIO
Depending on which version of EOSIO you use, there are different options available for finding the current time. What are they?
- 4,744
2
votes
2
answers
696
views
Make a transfer inline
I would like to send SYS token owned by the smart contract account to a third party account when anyone call a specific action. I have tried the following code but I am getting an error:
[[eosio::...
- 165
3
votes
1
answer
197
views
How do I set my smart-contract / account to "immutable"?
What's the correct cleos command to yield the active/owner permissions of a deployed contract to "eosio.code", exclusively?
1
vote
1
answer
86
views
`cleos get table` not returning vector<string>
I declare a vector vector<string> data inside a contract.
Contract Code:
book.emplace(_self, [&](struct wname &a){
a.name = fa.pubaddress;
a.namehash = ...
- 23
1
vote
1
answer
332
views
How to convert a public key string to a eosio::publickey object inside a smart contract?
The smart contract takes a string as an input for the public key. I need to convert it into a public key object within the contract.
- 11
0
votes
3
answers
413
views
Custom dispatcher new CDT
I'm having compilation issues when creating a custom dispatcher. I'm getting issues when calling EOSIO_DISPATCH. Is it related to changes in new CDT?
class [[eosio::contract("mycontract")]] ...
- 121
0
votes
2
answers
217
views
Multi_index issues
I'm getting a lot of errors related to multi_index after updating to the newest eosio.cdt. Here is part of my code related to hash.
struct st_hash {
capi_checksum256 hash;
uint64_t expiration;
...
- 121
0
votes
1
answer
73
views
Does EOSIO Have Native Contracts Built-Into Protocol Layer?
On the Bitshares site I read https://bitshares.org/technology/industrial-performance-scalability
Based upon the lessons we learn from LMAX, we know that a virtual machine for a blockchain should be ...
- 155
2
votes
1
answer
167
views
Issue while compiling smart contract - eosio.cdt
I have installed eosio.cdt in Ubuntu system by using commands from EOS Developers Portal
wget https://github.com/EOSIO/eosio.cdt/releases/download/v1.4.1/eosio.cdt-1.4.1.x86_64.deb
sudo apt install ./...
- 510
1
vote
2
answers
132
views
What can prevent one from changing contract code?
I find one major characteristic of EOSIO is that the smart contract code is interchangeable, so that developers can easily fix any bugs or change its logic.
But what if someone changes the code to ...
- 210
1
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0
answers
51
views
cannot get latest state of table after modifying table in inline action
As shown with code below, I modify table in an inline action, and then want to get the latest data. But the data I get is not the latest. Why?
void mycontract::myfunc()
{
action (
...
- 41
2
votes
1
answer
97
views
How to have real-time communication in dapp?
How would a real-time 1v1 game work on the EOS Blockchain?
I've noticed that many of the games/gambling dapps on EOS are mostly player vs. blockchain, like EOSBet.
Could I have real-time updates to ...
4
votes
2
answers
249
views
Require authorization with conditions require_auth(name1 OR name2)
Is there any possibility to implement conditional require_auth(<condition>) or what is a good practice to make contract accept invocations from a set of predetermined accounts? Is there any ...
- 53
2
votes
2
answers
98
views
Is there a way to prevent me spending tokens until an action is called?
I am creating a smart contract but came to a halt when writing the code.
Is there a way, in a smart contract, to prevent me from spending tokens transferred to me by another user through the smart ...
- 21
2
votes
2
answers
136
views
How to avoid cpu usage limits
Task
Compute some fields for all table rows when action called contract::priceupdate(price)
Input data:
Table with 10000 rows
Problem
Cpu limit 30ms so i cant update whole table in 1 transaction
...
- 123
0
votes
1
answer
176
views
Passing the action name having return type to EOSIO_DISPATCH in EOSIO smart contract
I have following EOSIO smart contract:
#include <eosiolib/eosio.hpp>
#include <eosiolib/print.hpp>
using namespace eosio;
class random : public contract
{
public:
using contract::...
- 307
1
vote
1
answer
148
views
Example of resource staking from contract
I'm looking for any relevant code example or documentation describing how to make contract stake resources for some account. I'm aware of delegatebw function of cleos however, I need the following ...
- 53
3
votes
1
answer
309
views
Deploy Contract from browser using eosjs
so I would like to deploy an EOS contract using eosjs. I encountered several problems (especially with converting the .abi and .wasm files).
All the examples either use node (so fs is available) or an ...
- 51
2
votes
0
answers
117
views
Where are deferred transaction errors logged to?
I'm trying to learn about deferred transactions.
I'm creating a bogus deferred transaction that invokes a non-existent action "fakeaction":
transaction out{};
out.actions.emplace_back(...
0
votes
1
answer
46
views
Can a contract know the creation date of accounts?
Is the creation date of accounts part of consensus? Can I query it within contracts? If so, how to do it?
0
votes
1
answer
607
views
How to list all balances of tokens managed by an eosio.token contract?
Let's say I have deployed the standard eosio.token contract to an account called "myeosiotoken," and I have used it to create an "ABC" token. Then, I issue 1,000 ABC to "someaccount1" and 2,000 ABC to ...
1
vote
1
answer
140
views
How to extend the functionality of eosio.token?
I want to create an EOSIO token with additional functionality. For example, I want users to be able to claim() an additional token per day (since e.g. account creation date).
Should I create a new ...
0
votes
1
answer
237
views
Token transfer missing_auth_exception
{
"code":500,"message":"Internal Service Error",
"error":{"code":3090004,"name":"missing_auth_exception",
"what":"Missing required authority",
"details":[{"message":"missing authority of thomsoimj21","...
0
votes
1
answer
110
views
How to deploy a contract to api-kylin.eosasia.one testnet
I have written a helloworld contract and got compiled that successfully
thomsonim123 is my kylin testnet account with some EOS when I want to deploy the contracct to the testnet I get few errors.
...
0
votes
1
answer
82
views
Is it possible to overload contract actions?
I had a method:
-- t.hpp --
[[eosio::action]]
void exchange();
-- t.cpp --
void token::exchange()
{
...
}
EOSIO_DISPATCH(eosio::token, (exchange))
and then decided that if a parameter were ...
- 515
1
vote
1
answer
509
views
Authorisation failure with deferred transaction
I have a contract action that does some cleanup:
void token::cleanup() { ... }
that I want to run asynchronously from another action like this: schedule("cleanup", 10). my scheduling method looks ...
- 515
0
votes
0
answers
86
views
Exception Details: 3080006 deadline_exception: Transaction took too long
I'm getting this error and have read all there is to read on the net (which isn't much) about it. mostly I see others complaining about this error when they run an action for the first time
in my ...
- 515
0
votes
2
answers
376
views
Erasing records with for loops
if I want to erase a table:
orderbook b(_self, _self.value);
auto m = b.get_index<name("idxprod")>();
for (auto &i : m) {
m.erase(i);
}
I get the error:
Error 3160005: The table ...
- 515
4
votes
1
answer
354
views
How to sort a table?
I'm following this explanation https://developers.eos.io/eosio-cpp/v1.1.0/docs/multi-index-table-tutorial using v1.5.0 of the CDT. Here's what I've got:
struct [[eosio::table]] order_struct {
...
- 515
1
vote
1
answer
40
views
Symbol stringification?
an action in my contract accepts an asset:
void token::burn(asset a)
which I want to print out:
printf("Asset [%s] burnt\n", a.symbol.to_string());
except the symbol class does not offer ...
- 515
1
vote
2
answers
57
views
Is there a way to check the histroy of a contract's table?
Is there a way to check the history after deleting the information in the table? For example, check yesterday's table information.
- 23
0
votes
2
answers
86
views
Asset instantiation woes
if I declare an asset:
asset a(10, symbol("TST", 0);
and I print it:
a.print();
I get pretty much what I'd expect:
TST
the format's not quite right (10 TST would have been better), but ...
- 515
1
vote
1
answer
121
views
Multiple print statements?
given the lack of debugging facilities in EOS contract development I add print() statements to my code, but I'm finding that only the first one gets printed, so:
print("HERE\n");
print("HERE\n");
...
- 515
0
votes
1
answer
1k
views
no member named 'print' in 'std::__1::basic_string<char>'
if I declare a string and attempt to print it like this:
std::string s;
eosio::print(s);
the EOS compiler pukes:
In file included from t.cpp:1: In file included from ./t.hpp:4: In
file included ...
- 515
1
vote
2
answers
170
views
Passing a string to an action?
I have an action that needs to operate on a string:
void token::MyAction(std::string key);
so I would expect I can make the call like this:
cleos push action MyAccount MyAction '["burn"]' -p ...
- 515
0
votes
2
answers
51
views
Referring to permissioned account within contract code?
I've created a table within a contract where I want to store user information. the .emplace() method's first parameter specifies the "scope" (I guess) for data to be stored and thus the user account
...
- 515
0
votes
1
answer
107
views
delay_sec is not accurate for deferred transaction
I have set some seconds but sometimes it is delayed more than 10 minutes. I know that delay_sec is not the accurate time because of the block production mechanism. The real time is much later than it ...
- 111
1
vote
2
answers
47
views
Error about billed CPU time when set Hello World Smart Contract
My VM Spec (VMWare ESXI)
CPU : Xeon CPU E5-2620 v2 @ 2.10GHz
Memory : 8GB
HDD : 70GB
EOS 1.5.3 , EOS.CDT 1.4.1 Compile from Source Code with AutoBuild Scripts.
I try to create first smart contract ...
0
votes
1
answer
196
views
EOSIO: name.value secondary index returns end iterator, even though searched value exists in table
I've got a multi-index table going with two secondary indices:
TABLE entry {
uint64_t id = 0;
eosio::name player;
std::vector<uint16_t> allocation;
...
- 61
1
vote
1
answer
103
views
Can a deferred transaction make the initial transaction fail
Imagine a user sending me some eosio.token to my contract and when I receive the notification, I start a new deferred transaction that fails later.
Can the deferred transaction make the initial ...
- 21
2
votes
1
answer
105
views
Multiple Inheritance within ABI files
I have various classes that use multiple inheritance, i.e.:
class A
{
};
class B
{
};
class C : public A, public B
{
};
Single inheritance in an ABI file is possible using the base layer as ...
- 4,744
0
votes
2
answers
302
views
Best way to read data from contract using eosjs or Cleos
How you read the data from your contracts, just by using actions? Or there is another way?
Thanks!
- 121
2
votes
3
answers
111
views
Updating existing token contract code
I have deployed a token on main net and called the create method to issue tokens. However, I would like to update the token code to add an extra feature.
I can't find any information on the best ...
- 121