MobxQuery

Class wrapper for @tanstack-query/core queries with MobX reactivity

Usage

Create an instance of MobxQuery with queryKey and queryFn parameters

const query = new MobxQuery({
  queryClient,
  abortSignal, // Helps you to automatically clean up query  
  queryKey: ['pets'],
  queryFn: async ({ signal, queryKey }) => {
    const response = await petsApi.fetchPets({ signal });
    return response.data;
  },
});

Features

enableOnDemand option

Query will be disabled until you request result for this query
Example:

const query = new MobxQuery({
  //...
  enableOnDemand: true
});
// happens nothing
query.result.data; // from this code line query starts fetching data

This option works as is if query will be "enabled", otherwise you should enable this query.

const query = new MobxQuery({
  enabled: false,
  enableOnDemand: true, 
  queryFn: () => {},
});
query.result.data; // nothing happened because query is disabled.

But if you set enabled as true and option enableOnDemand will be true too then query will be fetched only after user will try to get access to result.

const query = new MobxQuery({
  enabled: true,
  enableOnDemand: true, 
  queryFn: () => {},
});
...
// query is not fetched
...
// query is not fetched
query.result.data; // query starts execute the queryFn

dynamic options

Options which can be dynamically updated for this query

const query = new MobxQuery({
  // ...
  options: () => ({
    enabled: this.myObservableValue > 10,
    queryKey: ['foo', 'bar', this.myObservableValue] as const,
  }),
  queryFn: ({ queryKey }) => {
    const myObservableValue = queryKey[2];
  }
});

dynamic queryKey

Works the same as dynamic options option but only for queryKey

const query = new MobxQuery({
  // ...
  queryKey: () => ['foo', 'bar', this.myObservableValue] as const,
  queryFn: ({ queryKey }) => {
    const myObservableValue = queryKey[2];
  }
});

P.S. you can combine it with dynamic (out of box) enabled property

const query = new MobxQuery({
  // ...
  queryKey: () => ['foo', 'bar', this.myObservableValue] as const,
  enabled: ({ queryKey }) => queryKey[2] > 10,
  queryFn: ({ queryKey }) => {
    const myObservableValue = queryKey[2];
  }
});

method start(params)

Enable query if it is disabled then fetch the query.

method update()

Update options for query (Uses QueryObserver.setOptions)

hook onDone()

Subscribe when query has been successfully fetched data

hook onError()

Subscribe when query has been failed fetched data

method invalidate()

Invalidate current query (Uses queryClient.invalidateQueries)

method reset()

Reset current query (Uses queryClient.resetQueries)

method setData()

Set data for current query (Uses queryClient.setQueryData)

property isResultRequsted

Any time when you trying to get access to result property this field sets as true
This field is needed for enableOnDemand option
This property if observable

property result

Observable query result (The same as returns the useQuery hook)

About enabled

All queries are enabled (docs can be found here) by default, but you can set enabled as false or use dynamic value like ({ queryKey }) => !!queryKey[1]
You can use update method to update value for this property or use dynamic options construction (options: () => ({ enabled: !!this.observableValue }))

About refetchOnWindowFocus and refetchOnReconnect

They will not work if you will not call mount() method manually of your QueryClient instance which you send for your queries, all other cases dependents on query stale time and enabled properties.
Example:

import { hashKey, QueryClient } from '@tanstack/query-core';

export const queryClient = new QueryClient({
  defaultOptions: {
    queries: {
      throwOnError: true,
      queryKeyHashFn: hashKey,
      refetchOnWindowFocus: 'always',
      refetchOnReconnect: 'always',
      staleTime: 5 * 60 * 1000,
      retry: (failureCount, error) => {
        if ('status' in error && Number(error.status) >= 500) {
          return failureCount < 3;
        }
        return false;
      },
    },
    mutations: {
      throwOnError: true,
    },
  },
});

queryClient.mount(); // enable all subscriptions for online\offline and window focus/blur

If you work with MobxQueryClient then calling mount() is not needed.