如何在 pallet 中使用 serde_json？

Question

在我的托盘依赖项中使用 serde_json 时会抛出此错误：- ``

  #[weight=10_000]
    pub fn insert_data_class(origin,app_id:Vec<u8>,db_id:Vec<u8>,cid:Vec<u8>,data:Vec<u8>,signature:H512)->DispatchResult{
        let caller = ensure_signed(origin)?;
        let app_data = alioth_register::Module::<T>::check_ownership(&caller,&app_id);
        ensure!(app_data.0,Error::<T>::AppNotFound);
        let data_str = String::from_utf8(data.clone()).unwrap();
        let data_json = json!(data_str);
        let uid:Vec<u8> = data_json["uid"].to_string().as_bytes().to_vec();
        //let uuid_str = data_json["uuid"].to_string();
        let uuid:Vec<u8> = data_json["uuid"].to_string().as_bytes().to_vec();
        let  data1 = data.clone();
        let data1 = String::from_utf8(data1).unwrap();
        let user_data = alioth_users::Module::<T>::check_user_extern(&uuid,&app_id);
        ensure!(user_data.0,Error::<T>::UserNotFound);
        let class_data = alioth_class::Module::<T>::check_class(&db_id,&cid);
        ensure!(class_data.0,Error::<T>::ClassOrDatabaseNotFound);
        //I needed a public key for this purpose we are going to write a function in alioth-users
        let pub_key_ref:(bool,H256) = alioth_users::Module::<T>::get_public_key(&uuid,&app_id);
        ensure!(pub_key_ref.0,Error::<T>::ObjectNotCreated);

        //now we are going to verify the signature for the further transaction
        ensure!(sp_io::crypto::sr25519_verify(&Signature::from_h512(signature),data1.as_bytes(),&Public::from_h256(pub_key_ref.1)),Error::<T>::SignatureNotVerified);
        //its over now we are going ahead to check the uniqness of data and insert it later.
        let data_from_self = Self::check_obj_store(&uid,&cid);
        ensure!(!data_from_self.0,Error::<T>::DataIsNotUnique);
        let struct_data = ObjectData{
            duid:uid,
            object:data,
        };
        if data_from_self.1==0{
            let vec_data = vec![struct_data];
            <ObjectStore>::insert(cid,vec_data);
            Self::deposit_event(Event::ObjectCreated());
        }
        else{
            let mut vec_data = <ObjectStore>::get(&cid);
            vec_data.insert(vec_data.len(),struct_data);
            <ObjectStore>::insert(cid,vec_data);
            Self::deposit_event(Event::ObjectCreated());
        }
        Ok(())
    }**this code uses serde_json::json macro**

错误：运行为 node-template-runtime v3.0.0 (/home/corteri/Desktop/blockchain/new_tmp/substrate-node-template/runtime)

自定义构建命令失败

原因：进程未成功退出：/home/corteri/Desktop/blockchain/new_tmp/substrate-node-template/target/debug/build/node-template-runtime-e56bc02a2834241f/build-script-build（退出状态：1） --- 标准输出错误报告中应包含的信息。执行构建命令："rustup" "运行" "nightly" "cargo" "-Zfeatures=build_dep" "rustc" "--target=wasm32-unknown-unknown" "--manifest-path =/home/corteri/Desktop/blockchain/new_tmp/substrate-node-template/target/debug/wbuild/node-template-runtime/Cargo.toml" "--color=always" "--release" 使用 rustc 版本：rustc 1.56.0-nightly (b7404c898 2021-09-03)

--- 标准错误警告：标志 -Z features 已在 1.51 版本中稳定，不再需要现在可以通过在 Cargo.toml 中指定 resolver = "2" 来使用新功能解析器。有关详细信息，请参阅 https://doc.rust-lang.org/nightly/cargo/reference/features.html#feature-resolver-version-2。

 Compiling getrandom v0.2.1

错误：不支持目标，有关详细信息，请参阅：https://docs.rs/getrandom/#unsupported-targets --> /home/corteri/.cargo/registry/src/github.com-1ecc6299db9ec823/getrandom-0.2.1/src/lib.rs:214:9 | 214 | / compile_error!("不支持目标，有关详细信息，请参阅：
215 | | https://docs.rs/getrandom/#unsupported-targets"); | |_________________________________________________________________________^

错误[E0433]：未能解决：使用未声明的板条箱或模块imp --> /home/corteri/.cargo/registry/src/github.com-1ecc6299db9ec823/getrandom-0.2.1/src/lib.rs:236:5 | 236 | imp::getrandom_inner(目的地) | ^^^ 使用未声明的板条箱或模块 imp

有关此错误的更多信息，请尝试 rustc --explain E0433。错误：由于之前的 2 个错误

，无法编译 getrandom

Answer 1

getrandom/js 功能需要在您的 Cargo.toml:

中激活

# We enable it only for web-wasm check
# See https://docs.rs/getrandom/0.2.1/getrandom/#webassembly-support
getrandom = { version = "0.2", features = ["js"] }

（顺便说一句，我认为这不是 serde_json 特定错误）

如何在 pallet 中使用 serde_json？

How to use serde_json in pallet?

substrate