Headers for HTTP requests and responses.

In some situations, headers are immutable:

• HttpRequest andHttpClientResponse always have immutable headers.

• HttpResponse andHttpClientRequest have immutable headersfrom the moment the body is written to.

In these situations, the mutating methods throw exceptions.

For all operations on HTTP headers the header name iscase-insensitive.

To set the value of a header use theset() method:

request.headers.set(HttpHeaders.cacheControlHeader,                    'max-age=3600, must-revalidate');

To retrieve the value of a header use thevalue() method:

print(request.headers.value(HttpHeaders.userAgentHeader));

AnHttpHeaders object holds a list of values for each nameas the standard allows. In most cases a name holds only a single value,The most common mode of operation is to useset() for setting a value,andvalue() for retrieving a value.

Properties

chunkedTransferEncoding↔bool

Whether the connection uses chunked transfer encoding.

getter/setter pair

contentLength↔int

The value of thecontentLengthHeader header, if any.

getter/setter pair

contentType↔ContentType?

TheContentType of thecontentTypeHeader header, if any.

getter/setter pair

date↔DateTime?

The date specified by thedateHeader header, if any.

getter/setter pair

expires↔DateTime?

The date and time specified by theexpiresHeader header, if any.

getter/setter pair

hashCode→int

The hash code for this object.

no setterinherited

host↔String?

The value of thehostHeader header, if any.

getter/setter pair

ifModifiedSince↔DateTime?

The date and time specified by theifModifiedSinceHeader header, if any.

getter/setter pair

persistentConnection↔bool

Whether the connection is persistent (keep-alive).

getter/setter pair

port↔int?

The value of the port part of thehostHeader header, if any.

getter/setter pair

runtimeType→Type

A representation of the runtime type of the object.

no setterinherited

Methods

add(Stringname,Objectvalue, {boolpreserveHeaderCase =false})→ void

Adds a header value.

clear()→ void

Removes all headers.

forEach(voidaction(Stringname,List<String>values))→ void

Performs theaction on each header.

noFolding(Stringname)→ void

Disables folding for the header namedname when sending the HTTP header.

noSuchMethod(Invocationinvocation)→ dynamic

Invoked when a nonexistent method or property is accessed.

inherited

remove(Stringname,Objectvalue)→ void

Removes a specific value for a header name.

removeAll(Stringname)→ void

Removes all values for the specified header name.

set(Stringname,Objectvalue, {boolpreserveHeaderCase =false})→ void

Sets the headername tovalue.

toString()→String

A string representation of this object.

inherited

value(Stringname)→String?

Convenience method for the value for a single valued header.

Operators

operator ==(Objectother)→bool

The equality operator.

inherited

operator [](Stringname)→List<String>?

The values for the header namedname.

Constants

acceptCharsetHeader→ constString

acceptEncodingHeader→ constString

acceptHeader→ constString

acceptLanguageHeader→ constString

acceptRangesHeader→ constString

accessControlAllowCredentialsHeader→ constString

accessControlAllowHeadersHeader→ constString

accessControlAllowMethodsHeader→ constString

accessControlAllowOriginHeader→ constString

accessControlExposeHeadersHeader→ constString

accessControlMaxAgeHeader→ constString

accessControlRequestHeadersHeader→ constString

accessControlRequestMethodHeader→ constString

ageHeader→ constString

allowHeader→ constString

authorizationHeader→ constString

cacheControlHeader→ constString

connectionHeader→ constString

contentDisposition→ constString

contentEncodingHeader→ constString

contentLanguageHeader→ constString

contentLengthHeader→ constString

contentLocationHeader→ constString

contentMD5Header→ constString

contentRangeHeader→ constString

contentTypeHeader→ constString

cookieHeader→ constString

dateHeader→ constString

entityHeaders→ constList<String>

etagHeader→ constString

expectHeader→ constString

expiresHeader→ constString

fromHeader→ constString

generalHeaders→ constList<String>

hostHeader→ constString

ifMatchHeader→ constString

ifModifiedSinceHeader→ constString

ifNoneMatchHeader→ constString

ifRangeHeader→ constString

ifUnmodifiedSinceHeader→ constString

lastModifiedHeader→ constString

locationHeader→ constString

maxForwardsHeader→ constString

pragmaHeader→ constString

proxyAuthenticateHeader→ constString

proxyAuthorizationHeader→ constString

rangeHeader→ constString

refererHeader→ constString

requestHeaders→ constList<String>

responseHeaders→ constList<String>

retryAfterHeader→ constString

serverHeader→ constString

setCookieHeader→ constString

teHeader→ constString

trailerHeader→ constString

transferEncodingHeader→ constString

upgradeHeader→ constString

userAgentHeader→ constString

varyHeader→ constString

viaHeader→ constString

warningHeader→ constString

wwwAuthenticateHeader→ constString