Agent.query QueryFields example

Developers
1

Hi

I am trying to use agent.query to query a canister from typescript front-end in react native. I could not find any example of how it should be. Any help is much appreciated.
This is what I am trying to achieve: call test method of a canister from front-end using Http call. Specifically instead of ??? in the code below, I am not sure what to put as a valid QueryFields.

const authClient = await AuthClient.create();
    const identity = authClient.getIdentity();
    const agent = new HttpAgent({
        host: 'https://boundary.ic0.app/',
        identity,
    });
    
    const canisterId = Principal.fromText('4k2wq-cqaaa-aaaab-qac7q-cai');
    agent.query(canisterId, <????????>, identity, ).then((res)=>{
        console.log(res);
    })
2

to be more specific, I am having problem understandign arg parameter in queryFields

const queryData = {
        methodName: 'greet',
        arg: ??? how to build this?
}
3

Does your canister have a candid interface? The pattern we tend to use is to generate javascript declaration files from the .did file, which we then use with an abstraction of @dfinity/agent -Actor.createActor() so you don’t need to write the query manually

1 Like
4

yes I understand that approach, but wanted to see if there is a way to go directly with Http request approach? and if yes, how

5

It’s hard to answer in the abstract. You can inspect the source code of agent, or if you provide the interface you’re targeting I might be able to assemble it for you

1 Like