git.r.bdr.sh - rbdr/forum/blob - src/lib/stores/apollo.ts

   1 import { ApolloError } from '@apollo/client/core';
   2 import { readable } from 'svelte/store';
   3 import { client } from '$lib/config/apollo';
   4 import type { DocumentNode, ApolloQueryResult } from '@apollo/client/core';
   5
   6 import type { Readable } from 'svelte/store';
   7
   8 /*
   9  * This is a generic store for use with apollo
  10  */
  11
  12 type ApolloStoreConfiguration<Type> = {
  13         key: string;
  14         query: DocumentNode;
  15         initialValue?: Type | void;
  16         variables?: object;
  17 };
  18
  19 type ApolloStoreState<Type> = {
  20         loading: boolean;
  21         data: Type | void;
  22         error: Error | void;
  23 };
  24
  25 export const store = function store<Type>({
  26         key,
  27         query,
  28         initialValue = null,
  29         variables = {}
  30 }: ApolloStoreConfiguration<Type>): Readable<ApolloStoreState<Type>> {
  31         const initialState: ApolloStoreState<Type> = {
  32                 loading: true,
  33                 data: initialValue,
  34                 error: undefined
  35         };
  36
  37         return readable(initialState, (set) => {
  38                 const handleError = function (error: Error) {
  39                         return set({
  40                                 loading: false,
  41                                 data: initialValue,
  42                                 error
  43                         });
  44                 };
  45
  46                 client.watchQuery({ query, variables }).subscribe(
  47                         (result: ApolloQueryResult<Type>) => {
  48                                 if (result.errors) {
  49                                         const error = new ApolloError({ graphQLErrors: result.errors });
  50                                         return handleError(error);
  51                                 }
  52
  53                                 set({
  54                                         loading: false,
  55                                         data: result.data[key],
  56                                         error: undefined
  57                                 });
  58                         },
  59                         (error: Error) => handleError(error)
  60                 );
  61         });
  62 };