I have multiple queries combined in one request.
Later, when user make some changes I need to refetch only one of those combined queries with new variables.
I added directives #include on those queries that I don't need to fetch again.
The problem is, on refetch, my cache is overwritten with new data from that single query.
How can I persist my cache, and only update it on refetch with new data and not overwrite it?
const { loading, error, data, refetch } = useQuery(GET_DATA, {
fetchPolicy: 'network-only',
variables: {
something,
includeSummary: true,
},
});
refetch(
{
...variables,
includeSummary: false,
}
);
export const GET_DATA = gql`
query Something(
$args: DataInput
$includeSummary: Boolean!
) {
summary #include(if: $includeSummary) {
.......
}
dynamicData(args: $args) {
........
}
}
`;
Related
I'm looking for a way to read the value from cache for Apollo. On the page of Apollo, it only show the way to retrieve one as follow:
With readQuery
const READ_TODO = gql`
query ReadTodo($id: ID!) {
todo(id: $id) {
id
text
completed
}
}
`;
// Fetch the cached to-do item with ID 5
const { todo } = client.readQuery({
query: READ_TODO,
variables: { // Provide any required variables here. Variables of mismatched types will return `null`.
id: 5,
},
});
or with readFragment
const todo = client.readFragment({
id: 'Todo:5', // The value of the to-do item's cache ID
fragment: gql`
fragment MyTodo on Todo {
id
text
completed
}
`,
});
However, I can't select more than 1 todo at a time in both of them. I will have an array of IDs I'm not sure how many values will be in it. What is an excellent approach to this problem?
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} />
}
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.
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.
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!