Types

Overview

Types are used to describe the data to be processed. They constrain the range of value that can be accepted as input data or expected as result on each computation running in a runtime.

All the type definition functions are available under the t namespace.

Typescript SDK
Python SDK

import { t } from "@typegraph/sdk";

Scalar types

Type	GraphQL type	Description
`t.integer()`	`Int`	Represents signed 32-bit integers.
`t.float()`	`Float`	Represents signed double-precision values as specified by IEEE 754.
`t.boolean()`	`Boolean`	Represents `true` or `false`.
`t.string()`	`String`	Represents textual data as UTF-8 character sequences.
`t.file()`	—	Represents a file for upload.

The following scalar types are aliases to a t.string() type with a specific format.

t.uuid()
t.json()
t.email()
t.uri()
t.hostname()
t.ean()
t.phone()
t.date()
t.datetime()

Non-scalar types

Type	GraphQL type	Description
`t.optional()`	nullable	Represents a value that may be `null`.
`t.list()`	list	Represents a list of values.
`t.struct()`	interface	Represents a structured data value, consisting of fields which map to typed values.
`t.union()`	union	Represents a value which can be one of a set of specified types.
`t.either()`	union	Represents a value which can match one and only one of a set of specified types.
`t.func`	—	Represents an operation that has to be performed on the typegate.

Type constraints

Type constraints define an additional narrowing of the range of values that can be accepted for the type.

They can be passed in an object after the last required parameter on the type definition.

See the reference for each type below for the list of constraints available.

Example: The min constraint on the type t.integer()

Typescript SDK
Python SDK

// represents integers greater than or equal to `12`
t.integer({ min: 12 });

Names and type references

Each type has a unique name. If none is setImmediate, a random name will be generated during typegraph serialization.

Injection

Types

`t.boolean()`

The t.boolean() type represents boolean values, true or false.

`t.integer()`

The t.integer() type represents 32-bit integers.

t.integer([constraints]);

Constraints

Constraint	Description
`min`	The minimum value of the integer.
`max`	The maximum value of the integer.
`x_min`	The minimum value of the integer, exclusive.
`x_max`	The maximum value of the integer, exclusive.
`multiple_of`	The integer must be a multiple of this value.

Examples

Typescript SDK
Python SDK

// non-negative integer
const nonNegative = t.integer({ min: 0 });

// an integer in the range [18, 120)
const adultAge = t.integer({ min: 18, x_max: 120 });

// an even integer
const even = t.integer({ multiple_of: 2 });

`t.float()`

t.float([constraints])

The t.float() type represents numbers, stored in double precision floating-point format (IEEE 754).

Constraints

The t.float() type has the same constraints as t.integer(). See integer constraints.

`t.string()`

t.string([constraints])

The t.string() type represents textual data represented as UTF-8 character sequences.

Constraints

Constraint	Type	Description
`min`	Integer	Minimum length of the string.
`max`	Integer	Maximum length of the string.
`pattern`	String	Regular expression pattern that the string must match.
`format`	String	JSON schema format that the string must match. See below for the list of supported formats.

Supported formats

Here is the list of supported formats:

uuid
json
email
uri
hostname
ean
phone
date
date-time

Examples

Typescript SDK
Python SDK

// a non-empty string of maximum 64 characters
t.string({ min: 1, max: 64 });

// an email address
t.string({ format: "email" });

// a json data
t.string({ format: "json" });

Aliases

Typescript SDK
Python SDK

Alias	Equivalent declaration
`t.uuid()`	`t.string({ format: "uuid" })`
`t.email()`	`t.string({ format: "email" })`
`t.uri()`	`t.string({ format: "uri" })`
`t.json`	`t.string({ format: "json" })`
`t.ean()`	`t.string({ format: "ean" })`
`t.phone()`	`t.string({ format: "phone" })`
`t.date()`	`t.string({ format: "date" })`
`t.datetime()`	`t.string({ format: "date-time" })`

`t.file()`

t.file([constraints])

The t.file() represents files for upload.

Type Constraints

Constraint	Type	Description
`min`	Integer	Minimum size of the file in bytes.
`max`	Integer	Maximum size of the file in bytes.
`allow`	Array of strings	List of allowed `content-type`s

Examples

Typescript SDK
Python SDK

// A file of a minimum size of 1KB
t.file({ min: 1024 })

// A JPEG or PNG file less than 2KB
t.file({ max: 2048, allow: ["image/jpeg", "image/png"] })

`t.optional()`

t.optional(item_type)
item_type.optional() // equivalent syntactic sugar

Default value

If the type is used as an input type, the default value can be specified in the type definition.

Typescript SDK
Python SDK

t.string().optional({ defaultItem: "default value" })

`t.list()`

t.list(item_type, [constraints])

The t.list() type represents a sequence of values of the same type.

Constraints

Constraint	Type	Description
`min`	Integer	Minimum number of items.
`max`	Integer	Maximum number of items.
`unique_items`	Boolean	Whether the items must be unique.

Examples

Typescript SDK
Python SDK

# A list of strings
t.list(t.string())

# A list of unique strings
t.list(t.string(), { uniqueItems: true })

# A list of strings with at least 3 items
# and at most 10 items
t.list(t.string(), { min: 3, max: 10 })

`t.struct()`

t.struct(properties, [constraints])

The t.struct() type represents structured data, consisting of nemed properties with pre-defined types.

All the prperies are required unless the corresponding type is optional. In that case, the field is allowed to be missing from the value or be null.

Constraints

Constraint	Type	Description
`min`	Integer	Minimum number of fields.
`max`	Integer	Maximum number of fields.

Examples

Typescript SDK
Python SDK

// A user profile
const user = t.struct({
    id: t.uuid({ as_id: true }),
    email: t.email(),
    username: t.string({ min: 3, max: 64 }),
});

// A user profile with an optional `name
const user = t.struct({
    id: t.uuid({ as_id: true }),
    email: t.email(),
    username: t.string({ min: 3, max: 64 }),
    name: t.string({ min: 3, max: 64 }).optional(),
});

`t.union()` and `t.either()`

t.union(variants)
t.either(variants)

The t.union type represents a value that can be of any of the specified variants. The t.either type represents a value that must be of one and only one of the specified variants.

The variants parameter is an array of types.

`t.func()`

The t.func() type represents an operation to be performed on the typegate with the specified materializer.

Usually, the functions are not defined explicitly, but rather created with the runtime instance.

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Parameters

Parameter	Type	Description
input type	`t.struct()`	The type of the input data.
output type	any type	The type of the output data.
materializer	`Materializer`~	The materializer to use to perform the operation/computation.

Methods

Method	Purpose	Reference page
`rate`	Rate limiting	Rate limiting
`reduce`	Parameter transformation	`reduce`
`apply`	Parameter transformation	`apply`

Types

Overview​

Scalar types​

Non-scalar types​

Type constraints​

Names and type references​

Injection​

Types​

t.boolean()​

t.integer()​

Constraints​

Examples​

t.float()​

Constraints​

t.string()​

Constraints​

Supported formats​

Examples​

Aliases​

t.file()​

Type Constraints​

Examples​

t.optional()​

Default value​

t.list()​

Constraints​

Examples​

t.struct()​

Constraints​

Examples​

t.union() and t.either()​

t.func()​

Parameters​

Methods​

Overview

Scalar types

Non-scalar types

Type constraints

Names and type references

Injection

Types

`t.boolean()`

`t.integer()`

Constraints

Examples

`t.float()`

Constraints

`t.string()`

Constraints

Supported formats

Examples

Aliases

`t.file()`

Type Constraints

Examples

`t.optional()`

Default value

`t.list()`

Constraints

Examples

`t.struct()`

Constraints

Examples

`t.union()` and `t.either()`

`t.func()`

Parameters

Methods