**************** CLIENT
App.js:
-
How to manage Cache:
const cache = new InMemoryCache({ typePolicies: { Query: { fields: { clients: { merge(existing, incoming) { return incoming; }, },
-
merge function tells the cache to accept new incoming data, and allows it to overwrtie existing cache and update.
HOW TO CREATE GRAPHQL QUERY - only to get
const GET_CLIENTS = gqlquery getClients { clients { id name email phone } };
export { GET_CLIENTS } <-- use GET_CLIENTS
HOW TO CREATE MODIFY METHODS
const ADD_CLIENT = gql` mutation addClient($name: String!, $email: String!, $phone: String!) {
// add parameters
addClient(name: $name, email: $email, phone: $phone) {
id
name
email
phone
}
} `;
// addClient method is created const [addClient] = useMutation(ADD_CLIENT, {
// define variables variables: { name, email, phone },
// update cache like below
update(cache, { data: { addClient } }) {
// get existing clients
const { clients } = cache.readQuery({ query: GET_CLIENTS });
// add new Client
cache.writeQuery({
query: GET_CLIENTS,
data: { clients: [...clients, addClient] },
});
},