This repository is a demonstration of using Apollo Federation with the Python library Strawberry-GraphQL for handling mutation that access data from external services/subgraphs.
type ReviewMutation @key(fields: "productId") {
productId: String!
product: Product @external
currentUser: User @external
comment(body: String!): Review! @requires(fields: "product{upc} currentUser{id}")
}
type Mutation {
review(productId: String!): ReviewMutation!
}Included in the project is an example mutation, comment, that demonstrates how to fetch data from external services (product.upc from the products subgraph and currentUser.id from the accounts subgraph) in order to ensure consistency of the review.
Note that this approach requires the external key (such as productId) to be provided earlier in the mutation rather than packed into a single input type.
An example mutation query is provided for reference.
mutation ExampleMutation($productId: String!, $body: String!) {
review(productId: $productId){
comment(body: $body) {
...
}
}
}- Clone the repository
- Start the services:
docker-compose up - Access the sandbox at
http://localhost:4000 - [Optional] View a full example at this share link
Note: If you make any changes to Strawberry's schema, please run bash ./apollo-router/supergraph_compose.sh to update the *.graphql files.
For reference, the implementation of the ReviewMutation can be found in the following files:
- orders subgraph:
- accounts subgraph:
- products subgraph:
Please take a look at the above links for more information about how the code works.