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45 lines
2.1 KiB
Markdown
45 lines
2.1 KiB
Markdown
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# Remote Schema Customization
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## Motivation
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- Prevent name conflicts between remote schemas and other sources
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- Allow customization of third-party schemas to better fit with local naming conventions
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## Spec
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Add an optional `customization` object to the `add_remote_schema` API with the following form:
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```yaml
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customization:
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# if root_fields_namespace is absent, the fields
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# are merged into the query root directly
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root_fields_namespace: "something"
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type_names:
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prefix: some_prefix
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suffix: some_suffix
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# mapping takes precedence over prefix and suffix
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mapping:
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old_name: new_name
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field_names:
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- parent_type: old_type_name
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prefix: some_prefix
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suffix: some_suffix
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# mapping takes precedence over prefix and suffix
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mapping:
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old_name: new_name
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```
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- Type name prefix and suffix will be applied to all types in the schema except the root types (for query, mutation and subscription), types starting with `__`, standard scalar types (`Int`, `Float`, `String`, `Boolean`, and `ID`), and types with an explicit mapping.
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- Root types, types starting with `__` and standard scalar types may only be customized with an explicit mapping.
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- Fields that are part of an interface must be renamed consistently across all object types that implement that interface.
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## Implementation approach
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- After obtaining the remote schema via introspection we build customization functions (and their inverses) for the types and fields in the schema.
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- Customizations are validated against the schema to ensure that:
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- Field renamings of objects and interfaces are consistent
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- Customization does not result in two types, or two fields of the same type, being renamed to the same name.
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- The remote schema is customized using the customization functions to rename types and fields.
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- The field parser generators are modified so that they recognise the customized schema, but generate GraphQL queries with the original names to be sent to the remote server
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- We can uses aliases on the fields to make sure the response object has the customized fields names.
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