HttpHeaders class Null safety

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: Whether the connection uses chunked transfer encoding.
read / write
contentLength ↔ int: The value of the contentLengthHeader header, if any.
read / write
contentType ↔ ContentType?: The ContentType of the contentTypeHeader header, if any.
read / write
date ↔ DateTime?: The date specified by the dateHeader header, if any.
read / write
expires ↔ DateTime?: The date and time specified by the expiresHeader header, if any.
read / write
hashCode → int: The hash code for this object.
read-onlyinherited
host ↔ String?: The value of the hostHeader header, if any.
read / write
ifModifiedSince ↔ DateTime?: The date and time specified by the ifModifiedSinceHeader header, if any.
read / write
persistentConnection ↔ bool: Whether the connection is persistent (keep-alive).
read / write
port ↔ int?: The value of the port part of the hostHeader header, if any.
read / write
runtimeType → Type: A representation of the runtime type of the object.
read-onlyinherited

Methods

add(String name, Object value, {bool preserveHeaderCase = false}) → void: Adds a header value.
clear() → void: Removes all headers.
forEach(void action(String name, List<String> values)) → void: Performs the action on each header.
noFolding(String name) → void: Disables folding for the header named name when sending the HTTP header.
noSuchMethod(Invocation invocation) → dynamic: Invoked when a non-existent method or property is accessed.
inherited
remove(String name, Object value) → void: Removes a specific value for a header name.
removeAll(String name) → void: Removes all values for the specified header name.
set(String name, Object value, {bool preserveHeaderCase = false}) → void: Sets the header name to value.
toString() → String: A string representation of this object.
inherited
value(String name) → String?: Convenience method for the value for a single valued header.

Operators

operator ==(Object other) → bool: The equality operator.
inherited
operator [](String name) → List<String>?: The values for the header named name.

Constants

acceptCharsetHeader → const String: "accept-charset"
acceptEncodingHeader → const String: "accept-encoding"
acceptHeader → const String: "accept"
acceptLanguageHeader → const String: "accept-language"
acceptRangesHeader → const String: "accept-ranges"
accessControlAllowCredentialsHeader → const String: @Since("2.14")

'access-control-allow-credentials'
accessControlAllowHeadersHeader → const String: @Since("2.14")

'access-control-allow-headers'
accessControlAllowMethodsHeader → const String: @Since("2.14")

'access-control-allow-methods'
accessControlAllowOriginHeader → const String: @Since("2.14")

'access-control-allow-origin'
accessControlExposeHeadersHeader → const String: @Since("2.14")

'access-control-expose-headers'
accessControlMaxAgeHeader → const String: @Since("2.14")

'access-control-max-age'
accessControlRequestHeadersHeader → const String: @Since("2.14")

'access-control-request-headers'
accessControlRequestMethodHeader → const String: @Since("2.14")

'access-control-request-method'
ageHeader → const String: "age"
allowHeader → const String: "allow"
authorizationHeader → const String: "authorization"
cacheControlHeader → const String: "cache-control"
connectionHeader → const String: "connection"
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"
cookieHeader → const String: "cookie"
dateHeader → const String: "date"
entityHeaders → const List<String>: [allowHeader, contentEncodingHeader, contentLanguageHeader, contentLengthHeader, contentLocationHeader, contentMD5Header, contentRangeHeader, contentTypeHeader, expiresHeader, lastModifiedHeader]
etagHeader → const String: "etag"
expectHeader → const String: "expect"
expiresHeader → const String: "expires"
fromHeader → const String: "from"
generalHeaders → const List<String>: [cacheControlHeader, connectionHeader, dateHeader, pragmaHeader, trailerHeader, transferEncodingHeader, upgradeHeader, viaHeader, warningHeader]
hostHeader → const String: "host"
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"
lastModifiedHeader → const String: "last-modified"
locationHeader → const String: "location"
maxForwardsHeader → const String: "max-forwards"
pragmaHeader → const String: "pragma"
proxyAuthenticateHeader → const String: "proxy-authenticate"
proxyAuthorizationHeader → const String: "proxy-authorization"
rangeHeader → const String: "range"
refererHeader → const String: "referer"
requestHeaders → const List<String>: [acceptHeader, acceptCharsetHeader, acceptEncodingHeader, acceptLanguageHeader, authorizationHeader, expectHeader, fromHeader, hostHeader, ifMatchHeader, ifModifiedSinceHeader, ifNoneMatchHeader, ifRa…
responseHeaders → const List<String>: [acceptRangesHeader, ageHeader, etagHeader, locationHeader, proxyAuthenticateHeader, retryAfterHeader, serverHeader, varyHeader, wwwAuthenticateHeader]
retryAfterHeader → const String: "retry-after"
serverHeader → const String: "server"
setCookieHeader → const String: "set-cookie"
teHeader → const String: "te"
trailerHeader → const String: "trailer"
transferEncodingHeader → const String: "transfer-encoding"
upgradeHeader → const String: "upgrade"
userAgentHeader → const String: "user-agent"
varyHeader → const String: "vary"
viaHeader → const String: "via"
warningHeader → const String: "warning"
wwwAuthenticateHeader → const String: "www-authenticate"