Apollo GraphQL: Lazy loading data after SSR - graphql

I have the following code:
const HomeWithApollo = withApollo(compose(
graphql(HOME_QUERY, {
props({
data: { loading, page, fetchMore }
}) {
return {
loading,
page,
fetchLocations: () => {
return fetchMore({
query: ALL_LOCATIONS_QUERY,
updateQuery: (prev, {fetchMoreResult}) => {
if (!fetchMoreResult.data) { return prev; }
return {
data: [...prev, ...fetchMoreResult.data]
};
}
})
}
};
}
})
)(Home));
Before migrating to Apollo I loaded the ALL_LOCATIONS_QUERY as an isomorphic fetch client-side (basically an AJAX request). But I'm looking for the Apollo way and I'm not sure if I have it yet. I have a few questions.
Using graphql(QUERY_NAME, { options }), since I'm loading Home data and Locations data completely separately, should they be placed in separate, multiple graphql functions within the withApollo(compose([...here]) Higher Order Component?
Currently to get data from the fetchMore function I am doing the following, but something tells me that it should be done within state so Apollo is aware of it for caching. Any thoughts on this? Am I moving in the right direction?
async componentDidMount(){
const { data } = await this.props.fetchLocations();
this.setState({ locations: data.allLocations });
}
Thank you very much in advance!

Related

Query on page not refetching once navigating back to page

In my nextjs page I have the following hook (generated by using graphql-codegen) that fetches a graphql query.
const { data, error, loading, fetchMore, refetch, variables } = useGetShortlistQuery({
notifyOnNetworkStatusChange: true, // updates loading value
defaultOptions: {
variables: {
offset: undefined,
filterBy: undefined,
sortBy: SortBy.RecentlyAdded,
sortDirection: SortDirection.Desc,
},
},
});
This is the useGetShortlistQuery hook that is generated by graphql-codegen
export function useGetShortlistQuery(
baseOptions?: Apollo.QueryHookOptions<GetShortlistQuery, GetShortlistQueryVariables>,
) {
const options = { ...defaultOptions, ...baseOptions };
return Apollo.useQuery<GetShortlistQuery, GetShortlistQueryVariables>(GetShortlistDocument, options);
}
my component is wrapped in a HOC to enable Apollo Client
export default withApollo({ ssr: true })(Index);
The withApollo HOC uses #apollo/client and the cache property of the apollo client is as follows.
cache: new InMemoryCache({
typePolicies: {
Query: {
fields: {
getShortlist: {
keyArgs: [],
merge(existing: PaginatedProperties | undefined, incoming: PaginatedProperties): PaginatedProperties {
return {
...incoming,
properties: [...(existing?.properties || []), ...(incoming?.properties || [])],
};
},
},
},
},
},
}),
The problem I am having is that on this page I update the variables on the useGetShortlistQuery using refetch which, in turn, updates the data.
However, if I navigate to another page, then come back to this page using this component. It doesn't seem to retrigger the graphql query so returns the previous data.
If you are using getStaticProps (or getServerSideProps) with pre rendered pages, it is a known behavior. It is due to optimisation by Next.js not re-rendering components between page navigations, with pages like [id].js.
The trick is to have a key on components that you want to see refreshing. You have multiple ways to do so. Having a different key on components tells React that it should be re-rendering the components, and thus will trigger again the hooks.
Practical example:
export const getStaticProps: GetStaticProps = async ({ params }) => {
const data = getData() //something that fetches your data here
return {
props: {
// some other data you want to return...
// some unique value that will be on each page
key: data.key
},
}
}
const MyPage: NextPage<InferGetStaticPropsType<typeof getStaticProps>> = (props) => {
<div key={props.key} />
}

Why do I not have an Apollo cache-hit between a multi-response query and a single-item query for the same type?

I'm working on a vue3 project using #vue/apollo-composable and #graphql-codegen.
My index page does a search query. Each result from that query has a tile made on the page. I'm expecting the tile queries will be answered by the cache, but instead, they always miss.
At the page level I do this query:
query getTokens($limit: Int!) {
tokens(limit: $limit) {
...tokenInfo
}
}
Inside of the tile component I execute:
query getToken($id: uuid!){
token(id: $id) {
...tokenInfo
}
}
The fragment looks like this:
fragment tokenInfo on token {
id
name
}
Expectation: The cache would handle 100% of the queries inside the tile components. (I'm hoping to avoid the downfalls of serializing this data to vuex).
Reality: I get n+1 backend calls. I've tried a bunch of permutations including getting rid of the fragment. If I send the getToken call with fetchPolicy: 'cache-only' no data is returned.
The apollo client configuration is very basic:
const cache = new InMemoryCache();
const defaultClient = new ApolloClient({
uri: 'http://localhost:8080/v1/graphql',
cache: cache,
connectToDevTools: true,
});
const app = createApp(App)
.use(Store, StateKey)
.use(router)
.provide(DefaultApolloClient, defaultClient);
I'm also attaching a screenshot of my apollo dev tools. It appears that the cache is in fact getting populated with normalized data:
Any help would be greatly appreciated! :)
I've gotten this worked out thanks to #xadm's comment as well as some feedback I received on the Vue discord. Really my confusion is down to me being new to so many of these tools. Deciding to live on the edge and be a vue3 early adopter (which I love in many ways) made it even easier for me to be confused with the variance in documentation qualities right now.
That said, here is what I've got as a solution.
Problem: The actual problem is that, as configured, Apollo has no way to know that getTokens and getToken return the same type (token).
Solution: The minimum configuration I've found that resolves this is as follows:
const cache = new InMemoryCache({
typePolicies: {
Query: {
fields: {
token(_, { args, toReference }) {
return toReference({
__typename: 'token',
id: args?.id,
});
},
},
},
},
});
However, the feels.... kinda gross to me. Ideally, I'd love to see a way to just point apollo at a copy of my schema, or a schema introspection, and have it figure this out for me. If someone is aware of a better way to do that please let me know.
Better(?) Solution: In the short term here what I feel is a slightly more scalable solution:
type CacheRedirects = Record<string, FieldReadFunction>;
function generateCacheRedirects(types: string[]): CacheRedirects {
const redirects: CacheRedirects = {};
for (const type of types) {
redirects[type] = (_, { args, toReference }) => {
return toReference({
__typename: type,
id: args?.id,
});
};
}
return redirects;
}
const cache = new InMemoryCache({
typePolicies: {
Query: {
fields: {
...generateCacheRedirects(['token']),
},
},
},
});
If anyone has any improvements on these, please add a comment/solution! :)

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

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.
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.

Apollo client useQuery not updating data after useMutation

Using this mutation:
import produce from 'immer
const [createItem] = useMutation(CREATE_ITEM, {
update (client, { data: { createItem } }) {
const queryResults = client.readQuery({
query: GET_LATEST_ORDER,
variables: { orderDepth: 1 }
})
client.writeQuery({
query: GET_LATEST_ORDER,
variables: { orderDepth: 1 },
data: produce(queryResults, draft => {
draft.orders[0].items.push(createItem)
})
})
}
})
I am unable to get
const { loading, data, refetch } = useQuery(GET_LATEST_ORDER, {
variables: { orderDepth: 1 }
})
to show updated data after the mutation.
The apollo cache is updated correctly. But data on the useQuery does not change.
The issue ended up being the returned object from the mutation was not exactly the same. It was missing an #client field.
While obvious in hindsight no where I searched described this as a reason except for a comment I saw mentioning perhaps missing the __typename.
This would have been obvious had apollo thrown an error. However, no error was thrown, nor existed on the useQuery.

Apollo useQuery() - "refetch" is ignored if the response is the same

I am trying to use Apollo-client to pull my users info and stuck with this problem:
I have this Container component responsible for pulling the user's data (not authentication) once it is rendered. User may be logged in or not, the query returns either viewer = null or viewer = {...usersProps}.
Container makes the request const { data, refetch } = useQuery<Viewer>(VIEWER);, successfully receives the response and saves it in the data property that I use to read .viewer from and set it as my current user.
Then the user can log-out, once they do that I clear the Container's user property setUser(undefined) (not showed in the code below, not important).
The problem occurred when I try to re-login: Call of refetch triggers the graphql http request but since it returns the same data that was returned during the previous initial login - useQuery() ignores it and does not update data. Well, technically there could not be an update, the data is the same. So my code setUser(viewer); does not getting executed for second time and user stucks on the login page.
const { data, refetch } = useQuery<Viewer>(VIEWER);
const viewer = data && data.viewer;
useEffect(() => {
if (viewer) {
setUser(viewer);
}
}, [ viewer ]);
That query with the same response ignore almost makes sense, so I tried different approach, with callbacks:
const { refetch } = useQuery<Viewer>(VIEWER, {
onCompleted: data => {
if (data.viewer) {
setUser(data.viewer);
}
}
});
Here I would totally expect Apollo to call the onCompleted callback, with the same data or not... but it does not do that. So I am kinda stuck with this - how do I make Apollo to react on my query's refetch so I could re-populate user in my Container's state?
This is a scenario where apollo's caches come handy.
Client
import { resolvers, typeDefs } from './resolvers';
let cache = new InMemoryCache()
const client = new ApolloClient({
cache,
link: new HttpLink({
uri: 'http://localhost:4000/graphql',
headers: {
authorization: localStorage.getItem('token'),
},
}),
typeDefs,
resolvers,
});
cache.writeData({
data: {
isLoggedIn: !!localStorage.getItem('token'),
cartItems: [],
},
})
LoginPage
const IS_LOGGED_IN = gql`
query IsUserLoggedIn {
isLoggedIn #client
}
`;
function IsLoggedIn() {
const { data } = useQuery(IS_LOGGED_IN);
return data.isLoggedIn ? <Pages /> : <Login />;
}
onLogin
function Login() {
const { data, refetch } = useQuery(LOGIN_QUERY);
let viewer = data && data.viewer
if (viewer){
localStorage.setItem('token',viewer.token)
}
// rest of the stuff
}
onLogout
onLogout={() => {
client.writeData({ data: { isLoggedIn: false } });
localStorage.clear();
}}
For more information regarding management of local state. Check this out.
Hope this helps!

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