I found myself wanting to rewrite JSON files with `sed`. The problem is, then I want to run a formatter over them afterwards, and this will change the whole file, not just the area I touched. I would like to propose the nuclear option in remedying this: format everything now. This is a very large change that should make it easier to keep files to a consistent format in the future. I have chosen to use Prettier for this because (a) it has a useful `--write` command and (b) it also does GraphQL, Markdown, YAML, etc. I've elected to exclude two sets of files: 1. `crates/custom-connector/data/*.json`, because they are actually multiple JSON objects, one per line, which Prettier cannot parse. 2. `crates/lang-graphql/tests/**/*.graphql`, because it contains invalid GraphQL, and the parser is intended to work with strangely-formatted GraphQL. The main changes are standardizing whitespace, adding a newline at the end of files, and putting JSON arrays on one line when they fit. V3_GIT_ORIGIN_REV_ID: 92d4a535c34a3cc00721e8ddc6f17c5717e8ff76
4.6 KiB
Boolean Expression Types in OpenDD
Motivation
All mutations in NDC are implemented as standalone procedures, whose semantics are opaque to OpenDD. In order to provide the ability to filter rows on which a procedure would apply, NDC is introducing boolean expression types as procedure arguments. Consequently, we would also need to support boolean expressions as arguments in OpenDD. Since OpenDD already uses boolean expressions (called filter expressions) for filtering models as a part of select many, we would want to unify the two definitions.
Proposal
kind: ObjectFilterExpressionType
The first proposal is to introduce a new OpenDD object type for filter expressions. This will allow us to exact;u define filter expressions and reuse them across models and command arguments.
kind: ObjectFilterExpressionType
version: v1
definition:
name: AuthorFilterExpression
objectType: Author
dataConnectorName: my_db
dataConnectorObjectType: author
filterableFields:
- fieldName: id
comparisonExpression:
operators:
enableAll: true
- fieldName: name
comparisonExpression:
operators:
enableSpecific: ["_eq", "_like"]
graphql:
typeName: Author_bool_exp
Move type mappings to kind: ObjectType
Currently type mappings are specified as a part of model / command source, where
we define how the object types used in a particular model map to object types
used in the source data connector. It was designed this way so that
kind: ObjectType
was defined purely in terms of OpenDD and coupling to a
connector was done only in kind: Model
/ kind: Command
. However, now that
mutations will be opaque commands, we expect an ObjectType used within a model
to be commonly reused across multiple commands, making it verbose to redefine
the type mappings for every command.
Hence, the second proposal is to move type mappings as a part of
kind: ObjectType
and removed from kind: Model
/ kind: Command
. This is
also more intuitive to understand for a reader of OpenDD.
kind: ObjectType
version: v1
definition:
name: Author
fields:
- name: id
type: Int!
- name: name
type: String
dataConnectorTypeMapping: # Optional key
- dataConnectorName: my_db
dataConnectorObjectType: author
fieldMapping:
id:
column: author_id
name:
column: author_name
Update kind: Model / kind: Command
Since filter expressions and type mappings are now being defined elsewhere,
updates are needed to kind: Model
.
- Remove the
typeMappings
key from thesource
field of the model definition. - Remove the
filterExpressionType
key from thegraphql
field of the model definition. - Remove the
filterable_fields
key from the model definition. - Introduce a
filterExpressionType
key to the model definition, which is optional and points to an existingObjectFilterExpressionType
that is defined on the same object type as the model's object type.
kind: Model
version: v1
definition:
name: Authors
objectType: Author
filterExpressionType: AuthorFilterExpression
orderableFields: ...
graphql:
orderByExpressionType: Author_order_by
selectMany:
queryRootField: authors
source:
dataConnectorName: author
Similarly, we would remove typeMappings
key from the source
field of the
command definition.
Alternatives Considered
A couple of alternatives were considered, but rejected.
Implicit boolean expression types, fully qualified on reference
kind: Command
version: v1
definition:
arguments:
- name: where
type:
booleanExpression:
objectType: Author
filterableFields: ...
graphql:
typeName: Author_bool_exp
There would be too much repition and it would be the inconsistent with the rest of OpenDD where you can only refer to explicitly defined types.
Boolean expression types attached to kind: ObjectType
kind: ObjectType
version: v1
definition:
name: Author
fields: ...
filterExpressions:
name: AuthorFilterExpression
dataConnectorName: my_db
dataConnectorObjectType: author
filterableFields: ...
graphql:
typeName: Author_bool_exp
The problem with this is it is unclear whether the name AuthorFilterExpression
shares the same namespace with other OpenDD types.
- If yes, it is inconsistent to define a named OpenDD type that is not its own kind.
- If no, then type references become more complicated:
- name: id
type:
regular: Int!
- name: where
type:
booleanExpression: AuthorFilterExpression