tutorial_en.md

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QuickStart

Related tools

• cargo
• rust
• ontio-cdk

Start

1. generate ontio-cdk api doc

clone https://github.com/ontio/ontology-wasm-cdt-rust.git to local, go to the project root directory, execute cargo doc to generate ontio-cdk api doc。

2. Data type conversion in contract

• u64 convert to string

example

let s = 123.to_string();

• base58 convert to Address

example

let address = ostd::base58!("AFmseVrdL9f9oyCzZefL9tG6UbvhPbdYzM");

3. Verification signature in the contract

example

let flag = runtime::check_witness(&from);

4. Interaction between contracts

When calling other contracts in a contract, you need to serialize the parameters according to the parameters serialize standard of the target contract.

• wasmcontract invoke neovm contract

  • U128 should convert to byte array by types::to_neo_bytes() firstly, then invoke sink.write() to serialize;
  • Address should be serialized by sink.write_neovm_address()。
  • parameter serialize step
  1. The method parameters of the target contract are serialized in reverse order.
  2. After the method parameters are serialized, serialize the 83u8 and 193u8 bytecodes.
  3. serialize function name
  4. serialize 103u8
  5. serialize contract address

  example

  let mut sink = Sink::new(16);
  sink.write(to_neo_bytes(amount));
  sink.write_neovm_address(to);
  sink.write_neovm_address(from);
  sink.write(83u8);
  sink.write(193u8);
  sink.write("transfer".to_string());
  sink.write(103u8);
  sink.write(contract_address);
  let res = runtime::call_contract(contract_address, sink.bytes());
  

• wasm invoke native

  • The contract module encapsulates the method of calling the native contract

ontio-std instruction

1. abi module

• Sink : used to serialization data in contract

For the data type that implements the Encoder interface, you can serialize it directly with the sink.write() method. When initializing sink, a Vec is initialized and its initialization size needs to be specified.。

example

let mut sink = Sink::new(16);
sink.write(83u8);
sink.write("transfer".to_string());

• Source: used to deserialize of data in contract

For data types that implement the Decoder interface type, you can deserialize directly with the source.read().unwrap() method.

example

let input = runtime::input();
let mut source = Source::new(&input);
let (from, to, amount) = source.read().unwrap();

3. console

• debug：Used to print log information in contracts

example

 console::debug("debug");

4. contract

• ong：Encapsulates related operations that call ong in the contract, such as transferring, checking balances, and so on.。

  • allowance(from: &Address, to: &Address) query allowance balance example

    use ostd::contract::ont;
    ont::allowance(from, to)
    

  • approve(from: &Address, to: &Address, amount: U128) one address approve another address transfer assets example

    use ostd::contract::ont;
    ont::approve(from, to, amount)
    

  • balance_of query balance

    example

    use ostd::contract::ont;
    ong::balance_of(address)
    

  • transfer

    example

    let state = ont::State { from: from.clone(), to: to.clone(), amount: amount };
    ont::transfer(&[state])
    

  • transfer_from example

    ont::transfer_from(sender, from, to, amount)
    

• ont:Encapsulates related operations that call ont in the contract, Similar to ong。

5. database

• delete: delete data by key
• get : query data by key
• put : store data by key

example

use ostd::database;
database::put(from, frmbal);
let balance = database::get(owner).unwrap_or(0);

6. types

• Address: address is a byte array of length 20
• U128 : little endian integer

7. runtime

This module encapsulates the API for contract and chain interaction.

• timestamp() -> u64 get current timestamp

example

runtime::timestamp()

• block_height() -> u32 get current block height

example

runtime::block_height()

• address() -> Address get current contract address

example

runtime::address()

• caller() -> Address get caller contract address

example

runtime::caller()

• current_blockhash() -> H256 get current block hash

example

runtime::current_blockhash()

• current_txhash() -> H256 get current transaction hash

example

runtime::current_txhash()

• check_witness<T: AsRef<Addr>>(addr: T) -> bool verify signature

example

runtime::check_witness(addr)

• ret(data: &[u8]) -> ! Called at the end of the contract execution, returning the execution result

example

let mut dispatcher = ApiTestDispatcher::new(ApiTestInstance);
runtime::ret(&dispatcher.dispatch(&runtime::input()));

• notify(data: &[u8]) Events pushed in the contract

example

runtime::notify("success".as_bytes());

contract examples

oep4

oep5

oep8