Access GraphQLApi from AppSync through ARN

[renanmav]

We should allow using the AppSync.GraphQLApi without needing to instantiate it (new). Something similar that already exists is the fromFunctionArn of @aws-cdk/aws-lambda.

Use Case

When I would like to share my GraphQLApi across multiple stacks, this would be very useful.

Proposed Solution

Other

• 👋 I may be able to implement this feature request
• ⚠️ This feature might incur a breaking change

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This is a 🚀 Feature Request

[BryanPan342]

@renanmav Thanks for bringing up this feature 😃

I'm assuming the desired feature is simply a class that has access to the apiId and arn and adjusting implementation of DataSource and Resolver to just take the api.id:

aws-cdk/packages/@aws-cdk/aws-appsync/lib/data-source.ts

Line 105 in 7b8ef5b

apiId: props.api.apiId,

However, this will cause a problem with the implementation in resolver.ts here

aws-cdk/packages/@aws-cdk/aws-appsync/lib/resolver.ts

Line 77 in 7b8ef5b

this.resolver.addDependsOn(props.api.schema);

I'm a little apprehensive on passing around schema across stacks... so if we were to make it so that only apiId and arn are passed around.. then whatever stack that contains the GraphQLApi will need to be provisioned first.

Willing to have a discussion about this though so whoever has comments to this please chime in!