RequestPart class

Binds a multipart/form-data request part to a method parameter.

Used for handling file uploads and complex form data in multipart/form-data requests. Each part can contain binary data, form fields, or mixed content.

Parameters

  • value: Name of the request part to bind (defaults to parameter name)
  • required: Whether the part is mandatory (default: true)
  • contentType: Expected content type for validation
  • maxSize: Maximum allowed size in bytes

Example

@RestController()
class UploadController {
  @PostMapping('/upload')
  UploadResult uploadFile(
    @RequestPart('document') Uint8List fileData,
    @RequestPart('metadata', contentType: 'application/json') FileMetadata metadata
  ) {
    // Handles multipart form with 'document' and 'metadata' parts
    return storageService.storeFile(fileData, metadata);
  }
}

Validation Features

  • Content type validation when contentType is specified
  • Size validation with maxSize limit
  • Required part validation

Framework Integration

Processed by RequestPartResolver which handles multipart request parsing.

Inheritance
Annotations
  • @Target.new({TargetKind.parameter})
  • @ResolvedBy(RequestPartResolver())

Constructors

RequestPart({String? value, bool required = true, String? contentType, int? maxSize})
Binds a multipart/form-data request part to a method parameter.
const

Properties

annotationType → Type
Returns the annotation _type of this annotation.
no setterinherited
contentType → String?
Expected content type of the multipart part.
final
defaultValue → String?
Default value to use if the request element is not present.
finalinherited
hashCode → int
The hash code for this object.
no setterinherited
maxSize → int?
Maximum allowed size of the part in bytes.
final
required → bool
Whether the request element is mandatory.
finalinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
value → String?
Name of the request element to bind.
finalinherited

Methods

equalizedProperties() → List<Object?>
Mixin-style contract for value-based equality, hashCode, and toString.
override
equals(Object other) → bool
Checks whether the given object is logically equivalent to this annotation.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
Returns a string representation of this annotation.
override

Operators

operator ==(Object other) → bool
The equality operator.
inherited