为 Rust canisters生成 Candid 文件

Overview​

In versions of the Rusk CDK v0.11.0 and higher, the Candid export workflow has been changed. You can call the ic_cdk::export_candid!() macro to enable the Candid export behavior, then use the candid-extractor to extract the Candid from the canister's Wasm.

在 Rusk CDK v0.11.0 及更高版本中，Candid 导出工作流程已更改。 您可以调用 ic_cdk::export_candid!() 宏来启用 Candid 导出行为，然后使用 candid-extractor 从canister容器的 Wasm 中提取 Candid。

Preparation​

• Step 1: Upgrade ic-cdk dependency to v0.11.0 or higher:​

# Cargo.toml
[dependencies]
ic-cdk = "0.11.0"

• Step 2: Install candid-extractor:​

cargo install candid-extractor

With cargo-binstall you can install the prebuilt binary without waiting for compilation:

cargo binstall candid-extractor

Workflow​

• Step 1. Call the export_candid macro at the end of your lib.rs file:​

#[query]
fn hello(name: String) -> String {
    format!("Hello, {}!", name)
}

#[update]
fn world(name: String) -> String {
    format!("World, {}!", name)
}

// Enable Candid export
ic_cdk::export_candid!();

• Step 2: Compile the Canister Wasm module.​

cargo build --release --target wasm32-unknown-unknown --package <CANISTER>

The Wasm module will be at:

target/wasm32-unknown-unknown/release/<CANISTER>.wasm

• Step 3: Extract candid from the Wasm module and save to a file:​

candid-extractor target/wasm32-unknown-unknown/release/<CANISTER>.wasm > <CANISTER>.did