Headers class

Headers is a case-insensitive, unmodifiable map that stores headers.

Headers provide both raw access via map operations and type-safe accessors for standard HTTP headers.

Accessing Headers

router.get('/info', (req) {
  final headers = req.headers;

  // Type-safe accessors
  final userAgent = headers.userAgent;
  final contentType = headers.contentType;
  final contentLength = headers.contentLength;

  // Raw access
  final custom = headers['X-Custom-Header'];

  return Response.ok();
});

Setting Headers

final headers = Headers.build((h) {
  // Set standard headers
  h.contentType = ContentTypeHeader(
    mimeType: MimeType.json,
    charset: 'utf-8',
  );

  h.cacheControl = CacheControlHeader(
    maxAge: 3600,
    publicCache: true,
  );

  // Set custom headers
  h['X-API-Version'] = ['2.0'];
  h['X-Request-ID'] = ['abc123'];
});

Response.ok(headers: headers, body: Body.fromString('data'));

Common Type-Safe Headers

// Request headers
headers.authorization; // AuthorizationHeader?
headers.cookie;        // List<Cookie>
headers.accept;        // List<MediaType>
headers.userAgent;     // String?
headers.host;          // HostHeader?

// Response headers
headers.cacheControl;  // CacheControlHeader?
headers.setCookie;     // SetCookieHeader?
headers.location;      // Uri?
headers.contentType;   // ContentTypeHeader?

Inheritance

• Object
• MapView<String, Iterable<String>>
• UnmodifiableMapView<String, Iterable<String>>
• HeadersBase
• Headers

Available extensions

• HeadersEx

Constructors

Headers.build(void update(MutableHeaders))

factory

Headers.empty()

factory

Headers.fromMap(Map<String, Iterable<String>>? values)

factory

Properties

accept → AcceptHeader?

Available on Headers, provided by the HeadersEx extension

no setter

acceptEncoding → AcceptEncodingHeader?

Available on Headers, provided by the HeadersEx extension

no setter

acceptLanguage → AcceptLanguageHeader?

Available on Headers, provided by the HeadersEx extension

no setter

acceptRanges → AcceptRangesHeader?

Available on Headers, provided by the HeadersEx extension

no setter

accessControlAllowCredentials → bool?

Available on Headers, provided by the HeadersEx extension

no setter

accessControlAllowHeaders → AccessControlAllowHeadersHeader?

Available on Headers, provided by the HeadersEx extension

no setter

accessControlAllowMethods → AccessControlAllowMethodsHeader?

Available on Headers, provided by the HeadersEx extension

no setter

accessControlAllowOrigin → AccessControlAllowOriginHeader?

Available on Headers, provided by the HeadersEx extension

no setter

accessControlExposeHeaders → AccessControlExposeHeadersHeader?

Available on Headers, provided by the HeadersEx extension

no setter

accessControlMaxAge → int?

Available on Headers, provided by the HeadersEx extension

no setter

accessControlRequestHeaders → List<String>?

Available on Headers, provided by the HeadersEx extension

no setter

accessControlRequestMethod → Method?

Available on Headers, provided by the HeadersEx extension

no setter

age → int?

Available on Headers, provided by the HeadersEx extension

no setter

allow → Set<Method>?

Available on Headers, provided by the HeadersEx extension

no setter

authorization → AuthorizationHeader?

Available on Headers, provided by the HeadersEx extension

no setter

cacheControl → CacheControlHeader?

Available on Headers, provided by the HeadersEx extension

no setter

clearSiteData → ClearSiteDataHeader?

Available on Headers, provided by the HeadersEx extension

no setter

connection → ConnectionHeader?

Available on Headers, provided by the HeadersEx extension

no setter

contentDisposition → ContentDispositionHeader?

Available on Headers, provided by the HeadersEx extension

no setter

contentEncoding → ContentEncodingHeader?

Available on Headers, provided by the HeadersEx extension

no setter

contentLanguage → ContentLanguageHeader?

Available on Headers, provided by the HeadersEx extension

no setter

contentLength → int?

Available on Headers, provided by the HeadersEx extension

no setter

contentLocation → Uri?

Available on Headers, provided by the HeadersEx extension

no setter

contentRange → ContentRangeHeader?

Available on Headers, provided by the HeadersEx extension

no setter

contentSecurityPolicy → ContentSecurityPolicyHeader?

Available on Headers, provided by the HeadersEx extension

no setter

cookie → CookieHeader?

Available on Headers, provided by the HeadersEx extension

no setter

crossOriginEmbedderPolicy → CrossOriginEmbedderPolicyHeader?

Available on Headers, provided by the HeadersEx extension

no setter

crossOriginOpenerPolicy → CrossOriginOpenerPolicyHeader?

Available on Headers, provided by the HeadersEx extension

no setter

crossOriginResourcePolicy → CrossOriginResourcePolicyHeader?

Available on Headers, provided by the HeadersEx extension

no setter

date → DateTime?

Available on Headers, provided by the HeadersEx extension

no setter

entries → Iterable<MapEntry<String, Iterable<String>>>

The map entries of this Map.

no setter, inherited

etag → ETagHeader?

Available on Headers, provided by the HeadersEx extension

no setter

expect → ExpectHeader?

Available on Headers, provided by the HeadersEx extension

no setter

expires → DateTime?

Available on Headers, provided by the HeadersEx extension

no setter

forwarded → ForwardedHeader?

Available on Headers, provided by the HeadersEx extension

no setter

from → FromHeader?

Available on Headers, provided by the HeadersEx extension

no setter

hashCode → int

The hash code for this object.

no setter, inherited

host → HostHeader?

Available on Headers, provided by the HeadersEx extension

no setter

ifMatch → IfMatchHeader?

Available on Headers, provided by the HeadersEx extension

no setter

ifModifiedSince → DateTime?

Available on Headers, provided by the HeadersEx extension

no setter

ifNoneMatch → IfNoneMatchHeader?

Available on Headers, provided by the HeadersEx extension

no setter

ifRange → IfRangeHeader?

Available on Headers, provided by the HeadersEx extension

no setter

ifUnmodifiedSince → DateTime?

Available on Headers, provided by the HeadersEx extension

no setter

isEmpty → bool

Whether there is no key/value pair in the map.

no setter, inherited

isNotEmpty → bool

Whether there is at least one key/value pair in the map.

no setter, inherited

keys → Iterable<String>

The keys of this Map.

no setter, inherited

lastModified → DateTime?

Available on Headers, provided by the HeadersEx extension

no setter

length → int

The number of key/value pairs in the map.

no setter, inherited

location → Uri?

Available on Headers, provided by the HeadersEx extension

no setter

maxForwards → int?

Available on Headers, provided by the HeadersEx extension

no setter

origin → Uri?

Available on Headers, provided by the HeadersEx extension

no setter

permissionsPolicy → PermissionsPolicyHeader?

Available on Headers, provided by the HeadersEx extension

no setter

proxyAuthenticate → AuthenticationHeader?

Available on Headers, provided by the HeadersEx extension

no setter

proxyAuthorization → AuthorizationHeader?

Available on Headers, provided by the HeadersEx extension

no setter

range → RangeHeader?

Available on Headers, provided by the HeadersEx extension

no setter

referer → Uri?

Available on Headers, provided by the HeadersEx extension

no setter

referrerPolicy → ReferrerPolicyHeader?

Available on Headers, provided by the HeadersEx extension

no setter

retryAfter → RetryAfterHeader?

Available on Headers, provided by the HeadersEx extension

no setter

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

secFetchDest → SecFetchDestHeader?

Available on Headers, provided by the HeadersEx extension

no setter

secFetchMode → SecFetchModeHeader?

Available on Headers, provided by the HeadersEx extension

no setter

secFetchSite → SecFetchSiteHeader?

Available on Headers, provided by the HeadersEx extension

no setter

server → String?

Available on Headers, provided by the HeadersEx extension

no setter

setCookie → SetCookieHeader?

Available on Headers, provided by the HeadersEx extension

no setter

strictTransportSecurity → StrictTransportSecurityHeader?

Available on Headers, provided by the HeadersEx extension

no setter

te → TEHeader?

Available on Headers, provided by the HeadersEx extension

no setter

trailer → List<String>?

Available on Headers, provided by the HeadersEx extension

no setter

transferEncoding → TransferEncodingHeader?

Available on Headers, provided by the HeadersEx extension

no setter

upgrade → UpgradeHeader?

Available on Headers, provided by the HeadersEx extension

no setter

userAgent → String?

Available on Headers, provided by the HeadersEx extension

no setter

values → Iterable<Iterable<String>>

The values of this Map.

no setter, inherited

vary → VaryHeader?

Available on Headers, provided by the HeadersEx extension

no setter

via → List<String>?

Available on Headers, provided by the HeadersEx extension

no setter

wwwAuthenticate → AuthenticationHeader?

Available on Headers, provided by the HeadersEx extension

no setter

xForwardedFor → XForwardedForHeader?

Available on Headers, provided by the HeadersEx extension

no setter

xPoweredBy → String?

Available on Headers, provided by the HeadersEx extension

no setter

Methods

addAll(Map<String, Iterable<String>> other) → void

This operation is not supported by an unmodifiable map.

inherited

addEntries(Iterable<MapEntry<String, Iterable<String>>> entries) → void

This operation is not supported by an unmodifiable map.

inherited

cast<RK, RV>() → Map<RK, RV>

Provides a view of this map as having RK keys and RV instances, if necessary.

inherited

clear() → void

This operation is not supported by an unmodifiable map.

inherited

containsKey(Object? key) → bool

Whether this map contains the given key.

inherited

containsValue(Object? value) → bool

Whether this map contains the given value.

inherited

forEach(void action(String key, Iterable<String> value)) → void

Applies action to each key/value pair of the map.

inherited

map<K2, V2>(MapEntry<K2, V2> transform(String key, Iterable<String> value)) → Map<K2, V2>

Returns a new map where all entries of this map are transformed by the given convert function.

inherited

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

putIfAbsent(String key, Iterable<String> ifAbsent()) → Iterable<String>

This operation is not supported by an unmodifiable map.

inherited

remove(Object? key) → Iterable<String>?

This operation is not supported by an unmodifiable map.

inherited

removeWhere(bool test(String key, Iterable<String> value)) → void

This operation is not supported by an unmodifiable map.

inherited

toString() → String

A string representation of this object.

inherited

transform(void update(MutableHeaders)) → Headers

update(String key, Iterable<String> update(Iterable<String> value), {Iterable<String> ifAbsent()?}) → Iterable<String>

This operation is not supported by an unmodifiable map.

inherited

updateAll(Iterable<String> update(String key, Iterable<String> value)) → void

This operation is not supported by an unmodifiable map.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited

operator [](Object? key) → Iterable<String>?

The value for the given key, or null if key is not in the map.

inherited

operator []=(String key, Iterable<String> value) → void

This operation is not supported by an unmodifiable map.

inherited

Constants

accept → const HeaderAccessor<AcceptHeader>

Common Headers (Used in Both Requests and Responses)

acceptEncoding → const HeaderAccessor<AcceptEncodingHeader>

acceptEncodingHeader → const String

acceptHeader → const String

Request Headers

acceptLanguage → const HeaderAccessor<AcceptLanguageHeader>

acceptLanguageHeader → const String

acceptRanges → const HeaderAccessor<AcceptRangesHeader>

acceptRangesHeader → const String

Common Headers (Used in Both Requests and Responses)

accessControlAllowCredentials → const HeaderAccessor<bool>

accessControlAllowCredentialsHeader → const String

Response Headers

accessControlAllowHeaders → const HeaderAccessor<AccessControlAllowHeadersHeader>

accessControlAllowHeadersHeader → const String

accessControlAllowMethods → const HeaderAccessor<AccessControlAllowMethodsHeader>

accessControlAllowMethodsHeader → const String

accessControlAllowOrigin → const HeaderAccessor<AccessControlAllowOriginHeader>

accessControlAllowOriginHeader → const String

accessControlExposeHeaders → const HeaderAccessor<AccessControlExposeHeadersHeader>

accessControlExposeHeadersHeader → const String

accessControlMaxAge → const HeaderAccessor<int>

accessControlMaxAgeHeader → const String

accessControlRequestHeaders → const HeaderAccessor<List<String>>

accessControlRequestHeadersHeader → const String

accessControlRequestMethod → const HeaderAccessor<Method>

accessControlRequestMethodHeader → const String

age → const HeaderAccessor<int>

ageHeader → const String

all → const Set<HeaderAccessor<Object>>

allow → const HeaderAccessor<SplayTreeSet<Method>>

allowHeader → const String

authorization → const HeaderAccessor<AuthorizationHeader>

authorizationHeader → const String

cacheControl → const HeaderAccessor<CacheControlHeader>

cacheControlHeader → const String

clearSiteData → const HeaderAccessor<ClearSiteDataHeader>

clearSiteDataHeader → const String

connection → const HeaderAccessor<ConnectionHeader>

connectionHeader → const String

contentDisposition → const HeaderAccessor<ContentDispositionHeader>

contentDispositionHeader → const String

contentEncoding → const HeaderAccessor<ContentEncodingHeader>

contentEncodingHeader → const String

contentLanguage → const HeaderAccessor<ContentLanguageHeader>

contentLanguageHeader → const String

contentLength → const HeaderAccessor<int>

contentLengthHeader → const String

contentLocation → const HeaderAccessor<Uri>

contentLocationHeader → const String

contentRange → const HeaderAccessor<ContentRangeHeader>

contentRangeHeader → const String

contentSecurityPolicy → const HeaderAccessor<ContentSecurityPolicyHeader>

contentSecurityPolicyHeader → const String

contentTypeHeader → const String

cookie → const HeaderAccessor<CookieHeader>

cookieHeader → const String

crossOriginEmbedderPolicy → const HeaderAccessor<CrossOriginEmbedderPolicyHeader>

crossOriginEmbedderPolicyHeader → const String

crossOriginOpenerPolicy → const HeaderAccessor<CrossOriginOpenerPolicyHeader>

crossOriginOpenerPolicyHeader → const String

crossOriginResourcePolicy → const HeaderAccessor<CrossOriginResourcePolicyHeader>

crossOriginResourcePolicyHeader → const String

date → const HeaderAccessor<DateTime>

Date-related headers

dateHeader → const String

General Headers

etag → const HeaderAccessor<ETagHeader>

etagHeader → const String

expect → const HeaderAccessor<ExpectHeader>

expectHeader → const String

expires → const HeaderAccessor<DateTime>

expiresHeader → const String

forwarded → const HeaderAccessor<ForwardedHeader>

forwardedHeader → const String

from → const HeaderAccessor<FromHeader>

Request Headers

fromHeader → const String

host → const HeaderAccessor<HostHeader>

hostHeader → const String

ifMatch → const HeaderAccessor<IfMatchHeader>

ifMatchHeader → const String

ifModifiedSince → const HeaderAccessor<DateTime>

ifModifiedSinceHeader → const String

ifNoneMatch → const HeaderAccessor<IfNoneMatchHeader>

ifNoneMatchHeader → const String

ifRange → const HeaderAccessor<IfRangeHeader>

ifRangeHeader → const String

ifUnmodifiedSince → const HeaderAccessor<DateTime>

ifUnmodifiedSinceHeader → const String

lastModified → const HeaderAccessor<DateTime>

lastModifiedHeader → const String

location → const HeaderAccessor<Uri>

Response Headers

locationHeader → const String

maxForwards → const HeaderAccessor<int>

maxForwardsHeader → const String

origin → const HeaderAccessor<Uri>

General Headers

originHeader → const String

permissionsPolicy → const HeaderAccessor<PermissionsPolicyHeader>

permissionsPolicyHeader → const String

proxyAuthenticate → const HeaderAccessor<AuthenticationHeader>

proxyAuthenticateHeader → const String

proxyAuthorization → const HeaderAccessor<AuthorizationHeader>

proxyAuthorizationHeader → const String

range → const HeaderAccessor<RangeHeader>

rangeHeader → const String

referer → const HeaderAccessor<Uri>

refererHeader → const String

referrerPolicy → const HeaderAccessor<ReferrerPolicyHeader>

referrerPolicyHeader → const String

request → const Set<HeaderAccessor<Object>>

response → const Set<HeaderAccessor<Object>>

retryAfter → const HeaderAccessor<RetryAfterHeader>

retryAfterHeader → const String

secFetchDest → const HeaderAccessor<SecFetchDestHeader>

secFetchDestHeader → const String

secFetchMode → const HeaderAccessor<SecFetchModeHeader>

secFetchModeHeader → const String

secFetchSite → const HeaderAccessor<SecFetchSiteHeader>

secFetchSiteHeader → const String

server → const HeaderAccessor<String>

serverHeader → const String

setCookie → const HeaderAccessor<SetCookieHeader>

setCookieHeader → const String

strictTransportSecurity → const HeaderAccessor<StrictTransportSecurityHeader>

Security and Modern Headers

strictTransportSecurityHeader → const String

Security and Modern Headers

te → const HeaderAccessor<TEHeader>

teHeader → const String

trailer → const HeaderAccessor<List<String>>

trailerHeader → const String

transferEncoding → const HeaderAccessor<TransferEncodingHeader>

transferEncodingHeader → const String

upgrade → const HeaderAccessor<UpgradeHeader>

upgradeHeader → const String

userAgent → const HeaderAccessor<String>

userAgentHeader → const String

vary → const HeaderAccessor<VaryHeader>

varyHeader → const String

via → const HeaderAccessor<List<String>>

viaHeader → const String

wwwAuthenticate → const HeaderAccessor<AuthenticationHeader>

wwwAuthenticateHeader → const String

xForwardedFor → const HeaderAccessor<XForwardedForHeader>

xForwardedForHeader → const String

xPoweredBy → const HeaderAccessor<String>

xPoweredByHeader → const String