Abstract Syntax Tree (AST)
Hot Chocolate seems to focus solely around ObjectType, InputType et al. These types work as an interface to configure the GraphQL schema. This schema is used to parse and validate incoming requests. Under the hood, every query, mutation or subscription request is parsed into a so-called abstract syntax tree. Each node of this tree denotes a part of the incoming GraphQL query.
GraphQL
query Users { userName address { street nr }}
Syntax Node
Every node in a syntax tree implements ISyntaxNode.
💡 The
ToStringmethod of a syntax node prints the corresponding GraphQL syntax.
This interface defines the NodeKind of the node.
Node Kinds:
| Name | Description (Spec Link) | Context | Example |
|---|---|---|---|
| Name | All names. e.g. Field, Argument ... | Both | foo |
| NamedType | Denotes a reference to a type | Both | Foo |
| ListType | Definition of a list | Both | [Foo] |
| NonNullType | Definition of type that cannot be null | Both | Foo! |
| Argument | Representation of an argument. Has a Name and a Value | Both | foo: "bar" |
| Directive | Denotes a directive | Query | @foo |
| Document | Describes a complete file or request a GraphQL service operates on. | Query (out) | |
| OperationDefinition | Describes a graphql operation like query mutation or subscription | Query (out) | query Foo {} |
| VariableDefinition | The variables defined by an operation | Query (out) | (\$foo: String) |
| Variable | A variable | Query (out) | \$foo |
| SelectionSet | specifies a selection of Field, FragmentSpread or InlineFragment | Query (out) | {foo bar} |
| Field | Describes a field as a part of a selection set | Query (out) | foo |
| FragmentSpread | Denotes a spread of a FragemntDefinition | Query (out) | ...f1 |
| InlineFragment | Denotes an inline fragment | Query (out) | ... on Foo { bar} |
| FragmentDefinition | Defines the definition of a fragment | Query (out) | fragment f1 on Foo {} |
| IntValue | Denotes a int value | Query (in) | 1 |
| StringValue | Denotes a string value | Query (in) | "bar" |
| BooleanValue | Denotes a boolean value | Query (in) | true |
| NullValue | Denotes a null value | Query (in) | null |
| EnumValue | Denotes a enum value | Query (in) | FOO |
| FloatValue | Denotes a Float value | Query (in) | 0.2 |
| ListValue | Denotes a List value | Query (in) | ["string"] |
| ObjectValue | Denotes a ObjectValue value | Query (in) | {foo: "bar" } |
| ObjectField | Denotes a field of am input object type | Query (in) | foo: "bar" |
| SchemaDefinition | Definition of a schema | Schema | schema {} |
| OperationTypeDefinition | This defines one of the root operations Query, Mutation or Subscription on the schema-definiton | Schema | query:FooQuery |
| ScalarTypeDefinition | Definition of a scalar | Schema | scalar JSON |
| ObjectTypeDefinition | Definition of an object type | Schema | type Foo{} |
| FieldDefinition | Definition of a field | Schema | bar:String |
| InputValueDefinition | Definition of a input value of an argument | Schema | x: Float |
| InterfaceTypeDefinition | Definition of an interface | Schema | interface NamedEntity {} |
| UnionTypeDefinition | Definition of an union | Schema | union Ex = Foo | Bar |
| EnumTypeDefinition | Definition of an enum | Schema | enum Foo {BAR} |
| EnumValueDefinition | Definition of an enum value | Schema | BAR |
| InputObjectTypeDefinition | Definition of an input type definition | Schema | input FooInput {} |
| SchemaExtension | Definition of a schema extension | Schema | extend schema {} |
| ScalarTypeExtension | Definition of a scalar extension | Schema | extend scalar Foo @bar |
| ObjectTypeExtension | Definition of an object type extension | Schema | extend type Foo { name} |
| InterfaceTypeExtension | Definition of an interface type extension | Schema | extend interface NamedEntity {} |
| UnionTypeExtension | Definition of an union type extension | Schema | extend union Ex = Foo{} |
| EnumTypeExtension | Definition of an enum type extension | Schema | extend enum foo{} |
| InputObjectTypeExtension | Definition of an input types | Schema | input foo {} |
| DirectiveDefinition | Definition of a directive | Schema | directive @foo on |