Version: v2.0.0

Upgrading setVariables

Examples on how to migrate this.props.setVariables calls from the old API.

this.props.setVariables from the old API does not have a direct equivalent in the new API. A big reason for this change is that the new core no longer tracks how to refetch any specific sub-tree from the query. This makes the new core a lot faster, but requires explicit queries for how to fetch new data. Check out these four different scenarios:

initialVariables#

If the component doesn't actually use setVariables(), and just uses initialVariables to share values between JS and GraphQL, there are two alternative approaches:

  • Inline the value in the GraphQL query, potentially annotating with a GraphQL comment (i.e. # PAGE_SIZE).
  • Add the variable to the queries that use the fragment and pass it in when fetching the query. For this it can be useful to have a module with a collection of variables for your product.

Pagination#

Typical Relay Classic code:

// counterexample
this.props.relay.setVariables({
count: count + 10,
});
initialVariables: {
count: 10,
},
fragment on User {
friends(first: $count) {
# ...
}
}

This should be upgraded to use a PaginationContainer.

Changing Arguments#

Typical old code:

// counterexample
this.props.relay.setVariables({
search: newSearchTerm,
});
initialVariables: {
search: '',
}
fragment on User {
friends(named: $search, first: 10) {
# ...
}
}

This can be upgraded by using a RefetchContainer which allows you to specify the exact query to use to fetch the new data.

Show More#

Typical old code:

// counterexample
this.props.relay.setVariables({
showComments: true,
});
initialVariables: {
showComments: false,
}
fragment on FeedbackTarget {
comments(first: 10) @include(if: $showComments) {
# ...
}
}

This can be upgraded by conditionally rendering a QueryRenderer which will load the data once it is rendered. The code overhead of doing this is dramatically reduced with the new API.

Alternatively a RefetchContainer can also be used.

Last updated on by Tianyu Yao