124 lines
3.5 KiB
Markdown
124 lines
3.5 KiB
Markdown
# GraphQL
|
|
|
|
We use [Apollo] and [Vue Apollo][vue-apollo] for working with GraphQL
|
|
on the frontend.
|
|
|
|
In order to use GraphQL, you need to enable the `graphql` feature flag,
|
|
read more about [Feature Flags][feature-flags].
|
|
|
|
## Apollo Client
|
|
|
|
To save duplicated clients getting created in different apps, we have a
|
|
[default client][default-client] that should be used. This setups the
|
|
Apollo client with the correct URL and also sets the CSRF headers.
|
|
|
|
## GraphQL Queries
|
|
|
|
To save query compilation at runtime, webpack can directly import `.graphql`
|
|
files. This allows webpack to preprocess the query at compile time instead
|
|
of the client doing compilation of queries.
|
|
|
|
To distinguish queries from mutations and fragments, the following naming convention is recommended:
|
|
|
|
- `allUsers.query.graphql` for queries;
|
|
- `addUser.mutation.graphql` for mutations;
|
|
- `basicUser.fragment.graphql` for fragments.
|
|
|
|
## Usage in Vue
|
|
|
|
To use Vue Apollo, import the [Vue Apollo][vue-apollo] plugin as well
|
|
as the default client. This should be created at the same point
|
|
the Vue application is mounted.
|
|
|
|
```javascript
|
|
import Vue from 'vue';
|
|
import VueApollo from 'vue-apollo';
|
|
import createDefaultClient from '~/lib/graphql';
|
|
Vue.use(VueApollo);
|
|
|
|
const apolloProvider = new VueApollo({
|
|
defaultClient: createDefaultClient(),
|
|
});
|
|
|
|
new Vue({
|
|
...,
|
|
apolloProvider,
|
|
...
|
|
});
|
|
```
|
|
|
|
Read more about [Vue Apollo][vue-apollo] in the [Vue Apollo documentation](https://vue-apollo.netlify.com/guide/).
|
|
|
|
### Local state with Apollo
|
|
|
|
It is possible to manage an application state with Apollo by passing
|
|
in a resolvers object when creating the default client. The default state can be set by writing
|
|
to the cache after setting up the default client.
|
|
|
|
```javascript
|
|
import Vue from 'vue';
|
|
import VueApollo from 'vue-apollo';
|
|
import createDefaultClient from '~/lib/graphql';
|
|
Vue.use(VueApollo);
|
|
|
|
const defaultClient = createDefaultClient({
|
|
Query: {
|
|
...
|
|
},
|
|
Mutations: {
|
|
...
|
|
},
|
|
});
|
|
|
|
defaultClient.cache.writeData({
|
|
data: {
|
|
isLoading: true,
|
|
},
|
|
});
|
|
|
|
const apolloProvider = new VueApollo({
|
|
defaultClient,
|
|
});
|
|
```
|
|
|
|
Read more about local state management with Apollo in the [Vue Apollo documentation](https://vue-apollo.netlify.com/guide/local-state.html#local-state).
|
|
|
|
### Testing
|
|
|
|
With [Vue test utils][vue-test-utils] it is easy to quickly test components that
|
|
fetch GraphQL queries. The simplest way is to use `shallowMount` and then set
|
|
the data on the component
|
|
|
|
```javascript
|
|
it('tests apollo component', () => {
|
|
const vm = shallowMount(App);
|
|
|
|
vm.setData({
|
|
...mock data
|
|
});
|
|
});
|
|
```
|
|
|
|
Another possible way is testing queries with mocked GraphQL schema. Read more about this way in [Vue Apollo testing documentation](https://vue-apollo.netlify.com/guide/testing.html#tests-with-mocked-graqhql-schema)
|
|
|
|
## Usage outside of Vue
|
|
|
|
It is also possible to use GraphQL outside of Vue by directly importing
|
|
and using the default client with queries.
|
|
|
|
```javascript
|
|
import defaultClient from '~/lib/graphql';
|
|
import query from './query.graphql';
|
|
|
|
defaultClient.query(query)
|
|
.then(result => console.log(result));
|
|
```
|
|
|
|
Read more about the [Apollo] client in the [Apollo documentation](https://www.apollographql.com/docs/tutorial/client/).
|
|
|
|
[Apollo]: https://www.apollographql.com/
|
|
[vue-apollo]: https://github.com/Akryum/vue-apollo/
|
|
[feature-flags]: ../feature_flags.md
|
|
[default-client]: https://gitlab.com/gitlab-org/gitlab/blob/master/app/assets/javascripts/lib/graphql.js
|
|
[vue-test-utils]: https://vue-test-utils.vuejs.org/
|
|
[apollo-link-state]: https://www.apollographql.com/docs/link/links/state.html
|