Apollo: Defining `params` in withData?

Question

I'm learning the latest Apollo libs. This withData code is adapted from the Githunt-React Apollo demo:

const withData = graphql(GETIMS_QUERY, {
    options: ({ params }) => {
        console.log(params);

        return {
            variables: {
                "fromID": Meteor.userId(),
                "toID": `${params.toID}`,
            },
        };
    },
});

params is coming in undefined. The Apollo docs don't seem to say where it is defined.

Looking at this SO post, it appears that params is supposed to contain the props passed to the component. But it always comes in undefined here.

How can I fix this?

Thanks in advance to all for any info.

Answer 1

Fixed it. {params} (in curly braces) had to be changed to props (no curly braces):

const withData = graphql(GETIMS_QUERY, {
    options: (props) => {
        console.log(props);

        return {
            variables: {
                "fromID": Meteor.userId(),
                "toID": props.toID,
            },
        };
    },
});

What I don't yet understand is, why does the Githunt-React Apollo demo code, have it in curly braces?

If you know, please post your response as an answer, and upon confirmation I will mark it as the accepted answer to this question. :)