dart:io

HttpHeaders class

Headers for HTTP requests and responses.

In some situations, headers are immutable:

• HttpRequest and HttpClientResponse always have immutable headers.

• HttpResponse and HttpClientRequest have immutable headers from the moment the body is written to.

In these situations, the mutating methods throw exceptions.

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

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

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

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

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

An HttpHeaders object holds a list of values for each name as the standard allows. In most cases a name holds only a single value, The most common mode of operation is to use set() for setting a value, and value() for retrieving a value.

Constructors

HttpHeaders()

Properties

chunkedTransferEncoding ↔ bool

read / write

Gets and sets the chunked transfer encoding header value.

contentLength ↔ int

read / write

Gets and sets the content length header value.

contentType ↔ ContentType

read / write

Gets and sets the content type. Note that the content type in the header will only be updated if this field is set directly. Mutating the returned current value will have no effect.

date ↔ DateTime

read / write

Gets and sets the date. The value of this property will reflect the 'date' header.

expires ↔ DateTime

read / write

Gets and sets the expiry date. The value of this property will reflect the 'expires' header.

host ↔ String

read / write

Gets and sets the host part of the 'host' header for the connection.

ifModifiedSince ↔ DateTime

read / write

Gets and sets the "if-modified-since" date. The value of this property will reflect the "if-modified-since" header.

persistentConnection ↔ bool

read / write

Gets and sets the persistent connection header value.

port ↔ int

read / write

Gets and sets the port part of the 'host' header for the connection.

hashCode → int

read-only, inherited

The hash code for this object. [...]

runtimeType → Type

read-only, inherited

A representation of the runtime type of the object.

Methods

add(String name, Object value) → void

Adds a header value. The header named name will have the value value added to its list of values. Some headers are single valued, and for these adding a value will replace the previous value. If the value is of type DateTime a HTTP date format will be applied. If the value is a List each element of the list will be added separately. For all other types the default toString method will be used.

clear() → void

Remove all headers. Some headers have system supplied values and for these the system supplied values will still be added to the collection of values for the header.

forEach(void f(String name, List<String> values)) → void

Enumerates the headers, applying the function f to each header. The header name passed in name will be all lower case.

noFolding(String name) → void

Disables folding for the header named name when sending the HTTP header. By default, multiple header values are folded into a single header line by separating the values with commas. The 'set-cookie' header has folding disabled by default.

remove(String name, Object value) → void

Removes a specific value for a header name. Some headers have system supplied values and for these the system supplied values will still be added to the collection of values for the header.

removeAll(String name) → void

Removes all values for the specified header name. Some headers have system supplied values and for these the system supplied values will still be added to the collection of values for the header.

set(String name, Object value) → void

Sets a header. The header named name will have all its values cleared before the value value is added as its value.

value(String name) → String

Convenience method for the value for a single valued header. If there is no header with the provided name, null will be returned. If the header has more than one value an exception is thrown.

noSuchMethod(Invocation invocation) → dynamic

inherited

Invoked when a non-existent method or property is accessed. [...]

toString() → String

inherited

Returns a string representation of this object.

Operators

operator [](String name) → List<String>

Returns the list of values for the header named name. If there is no header with the provided name, null will be returned.

operator ==(dynamic other) → bool

inherited

The equality operator. [...]

Constants

ACCEPT → const String

@Deprecated("Use acceptHeader instead")

acceptHeader

ACCEPT_CHARSET → const String

@Deprecated("Use acceptCharsetHeader instead")

acceptCharsetHeader

ACCEPT_ENCODING → const String

@Deprecated("Use acceptEncodingHeader instead")

acceptEncodingHeader

ACCEPT_LANGUAGE → const String

@Deprecated("Use acceptLanguageHeader instead")

acceptLanguageHeader

ACCEPT_RANGES → const String

@Deprecated("Use acceptRangesHeader instead")

acceptRangesHeader

acceptCharsetHeader → const String

"accept-charset"

acceptEncodingHeader → const String

"accept-encoding"

acceptHeader → const String

"accept"

acceptLanguageHeader → const String

"accept-language"

acceptRangesHeader → const String

"accept-ranges"

AGE → const String

@Deprecated("Use ageHeader instead")

ageHeader

ageHeader → const String

"age"

ALLOW → const String

@Deprecated("Use allowHeader instead")

allowHeader

allowHeader → const String

"allow"

AUTHORIZATION → const String

@Deprecated("Use authorizationHeader instead")

authorizationHeader

authorizationHeader → const String

"authorization"

CACHE_CONTROL → const String

@Deprecated("Use cacheControlHeader instead")

cacheControlHeader

cacheControlHeader → const String

"cache-control"

CONNECTION → const String

@Deprecated("Use connectionHeader instead")

connectionHeader

connectionHeader → const String

"connection"

CONTENT_ENCODING → const String

@Deprecated("Use contentEncodingHeader instead")

contentEncodingHeader

CONTENT_LANGUAGE → const String

@Deprecated("Use contentLanguageHeader instead")

contentLanguageHeader

CONTENT_LENGTH → const String

@Deprecated("Use contentLengthHeader instead")

contentLengthHeader

CONTENT_LOCATION → const String

@Deprecated("Use contentLocationHeader instead")

contentLocationHeader

CONTENT_MD5 → const String

@Deprecated("Use contentMD5Header instead")

contentMD5Header

CONTENT_RANGE → const String

@Deprecated("Use contentRangeHeader instead")

contentRangeHeader

CONTENT_TYPE → const String

@Deprecated("Use contentTypeHeader instead")

contentTypeHeader

contentEncodingHeader → const String

"content-encoding"

contentLanguageHeader → const String

"content-language"

contentLengthHeader → const String

"content-length"

contentLocationHeader → const String

"content-location"

contentMD5Header → const String

"content-md5"

contentRangeHeader → const String

"content-range"

contentTypeHeader → const String

"content-type"

COOKIE → const String

@Deprecated("Use cookieHeader instead")

cookieHeader

cookieHeader → const String

"cookie"

DATE → const String

@Deprecated("Use dateHeader instead")

dateHeader

dateHeader → const String

"date"

ENTITY_HEADERS → const List<String>

@Deprecated("Use entityHeaders instead")

entityHeaders

entityHeaders → const List<String>

const [allowHeader, contentEncodingHeader, contentLanguageHeader, contentLengthHeader, contentLocationHeader, contentMD5Header, contentRangeHeader, contentTypeHeader, expiresHeader, lastModifiedHeader…

ETAG → const String

@Deprecated("Use etagHeader instead")

etagHeader

etagHeader → const String

"etag"

EXPECT → const String

@Deprecated("Use expectHeader instead")

expectHeader

expectHeader → const String

"expect"

EXPIRES → const String

@Deprecated("Use expiresHeader instead")

expiresHeader

expiresHeader → const String

"expires"

FROM → const String

@Deprecated("Use fromHeader instead")

fromHeader

fromHeader → const String

"from"

GENERAL_HEADERS → const List<String>

@Deprecated("Use generalHeaders instead")

generalHeaders

generalHeaders → const List<String>

const [cacheControlHeader, connectionHeader, dateHeader, pragmaHeader, trailerHeader, transferEncodingHeader, upgradeHeader, viaHeader, warningHeader]

HOST → const String

@Deprecated("Use hostHeader instead")

hostHeader

hostHeader → const String

"host"

IF_MATCH → const String

@Deprecated("Use ifMatchHeader instead")

ifMatchHeader

IF_MODIFIED_SINCE → const String

@Deprecated("Use ifModifiedSinceHeader instead")

ifModifiedSinceHeader

IF_NONE_MATCH → const String

@Deprecated("Use ifNoneMatchHeader instead")

ifNoneMatchHeader

IF_RANGE → const String

@Deprecated("Use ifRangeHeader instead")

ifRangeHeader

IF_UNMODIFIED_SINCE → const String

@Deprecated("Use ifUnmodifiedSinceHeader instead")

ifUnmodifiedSinceHeader

ifMatchHeader → const String

"if-match"

ifModifiedSinceHeader → const String

"if-modified-since"

ifNoneMatchHeader → const String

"if-none-match"

ifRangeHeader → const String

"if-range"

ifUnmodifiedSinceHeader → const String

"if-unmodified-since"

LAST_MODIFIED → const String

@Deprecated("Use lastModifiedHeader instead")

lastModifiedHeader

lastModifiedHeader → const String

"last-modified"

LOCATION → const String

@Deprecated("Use locationHeader instead")

locationHeader

locationHeader → const String

"location"

MAX_FORWARDS → const String

@Deprecated("Use maxForwardsHeader instead")

maxForwardsHeader

maxForwardsHeader → const String

"max-forwards"

PRAGMA → const String

@Deprecated("Use pragmaHeader instead")

pragmaHeader

pragmaHeader → const String

"pragma"

PROXY_AUTHENTICATE → const String

@Deprecated("Use proxyAuthenticateHeader instead")

proxyAuthenticateHeader

PROXY_AUTHORIZATION → const String

@Deprecated("Use proxyAuthorizationHeader instead")

proxyAuthorizationHeader

proxyAuthenticateHeader → const String

"proxy-authenticate"

proxyAuthorizationHeader → const String

"proxy-authorization"

RANGE → const String

@Deprecated("Use rangeHeader instead")

rangeHeader

rangeHeader → const String

"range"

REFERER → const String

@Deprecated("Use refererHeader instead")

refererHeader

refererHeader → const String

"referer"

REQUEST_HEADERS → const List<String>

@Deprecated("Use requestHeaders instead")

requestHeaders

requestHeaders → const List<String>

const [acceptHeader, acceptCharsetHeader, acceptEncodingHeader, acceptLanguageHeader, authorizationHeader, expectHeader, fromHeader, hostHeader, ifMatchHeader, ifModifiedSinceHeader, ifNoneMatchHeader…

RESPONSE_HEADERS → const List<String>

@Deprecated("Use responseHeaders instead")

responseHeaders

responseHeaders → const List<String>

const [acceptRangesHeader, ageHeader, etagHeader, locationHeader, proxyAuthenticateHeader, retryAfterHeader, serverHeader, varyHeader, wwwAuthenticateHeader]

RETRY_AFTER → const String

@Deprecated("Use retryAfterHeader instead")

retryAfterHeader

retryAfterHeader → const String

"retry-after"

SERVER → const String

@Deprecated("Use serverHeader instead")

serverHeader

serverHeader → const String

"server"

SET_COOKIE → const String

@Deprecated("Use setCookieHeader instead")

setCookieHeader

setCookieHeader → const String

"set-cookie"

TE → const String

@Deprecated("Use teHeader instead")

teHeader

teHeader → const String

"te"

TRAILER → const String

@Deprecated("Use trailerHeader instead")

trailerHeader

trailerHeader → const String

"trailer"

TRANSFER_ENCODING → const String

@Deprecated("Use transferEncodingHeader instead")

transferEncodingHeader

transferEncodingHeader → const String

"transfer-encoding"

UPGRADE → const String

@Deprecated("Use upgradeHeader instead")

upgradeHeader

upgradeHeader → const String

"upgrade"

USER_AGENT → const String

@Deprecated("Use userAgentHeader instead")

userAgentHeader

userAgentHeader → const String

"user-agent"

VARY → const String

@Deprecated("Use varyHeader instead")

varyHeader

varyHeader → const String

"vary"

VIA → const String

@Deprecated("Use viaHeader instead")

viaHeader

viaHeader → const String

"via"

WARNING → const String

@Deprecated("Use warningHeader instead")

warningHeader

warningHeader → const String

"warning"

WWW_AUTHENTICATE → const String

@Deprecated("Use wwwAuthenticateHeader instead")

wwwAuthenticateHeader

wwwAuthenticateHeader → const String

"www-authenticate"