How can I use Apollo's cacheRedirect with a nested query - caching

Question

I've got a query that looks like this:
export const GET_PROJECT = gql`
query GetProject($id: String!) {
homework {
getProject(id: $id) {
...ProjectFields
}
}
}
${ProjectFieldsFragment}
`;
My InMemoryCache looks like this:
const cache = new InMemoryCache({
dataIdFromObject: ({ id }) => id,
cacheRedirects: {
Query: {
getProject: (_, args, obj) => {
console.log('Hello world');
},
},
}
});
The above cache redirect is never hit. However, if I modify it to look like:
const cache = new InMemoryCache({
dataIdFromObject: ({ id }) => id,
cacheRedirects: {
Query: {
homework: (_, args, obj) => {
console.log('Hello world');
},
},
}
});
It does get hit, however I don't have any of the arguments that are passed in the nested getProject query. What's also confusing is that this cache redirect function is hit for queries that it seemingly shouldn't get hit for, like:
export const SESSION = gql`
query Session {
session {
user {
id
fullName
email
}
organizations {
name
id
}
}
}
`;
So what is going on? I've resorted to just using readFragment in the places where I want the cache to redirect, but I'd like for that logic to become centralized.

Answer 1

It's hard to say for sure with these kinds of issues, but I'm betting that, since you say
What's also confusing is that this cache redirect function is hit for queries that it seemingly shouldn't get hit for
the issue might be with your dataIdFromObject function.
This function is ultimately what decides if data is read from the cache or not. You should only override this if you have a very specific reason to. For example:
import { InMemoryCache, defaultDataIdFromObject } from 'apollo-cache-inmemory';
// ...
export default new ApolloClient({
link,
cache: new InMemoryCache({
dataIdFromObject(object) {
switch (object.__typename) {
case 'ModifierScale':
case 'ModifierGroup':
return [
object.__typename,
object.id,
...object.defaults
.map((defaultModifier) => defaultModifier.id)
.join(''),
].join('');
default:
return defaultDataIdFromObject(object); // fall back to default handling
}
},
}),
});
The point of this setting is to allow you to customize the key that gets put into the cache when you are loading the data.
If this doesn't solve your issue, I would definitely go into the Apollo tab in the chrome dev tools (you need the Apollo dev tools chrome extension to do this) and look at the cache section. It should show you the data in the cache and the key that the data is stored in.