http

This module provides the API to a HTTP/1.1 client according to RFC 2616, caching is currently not supported.

There are some usage examples in the Inets User's Guide.

Type definitions that are used more than once in this module:

boolean()    = true | false 
string()     = list of ASCII characters 
request_id() = ref() 
profile()    = atom()
path()       = string() representing a file path or directory path 
ip_address() = See inet(3)
    

Type definitions that are related to HTTP:

For more information about HTTP see rfc 2616

method()        = head | get | put | post | trace | options | delete
request()       = {url(), headers()} | 
                  {url(), headers(), content_type(), body()}
url()           = string() - Syntax according to the URI definition in rfc 2396, ex: "http://www.erlang.org"
status_line()   = {http_version(), status_code(), reason_phrase()}
http_version()  = string() ex: "HTTP/1.1"
status_code()   = integer()
reason_phrase() = string()
content_type()  = string()
headers()       = [header()]
header()        = {field(), value()}
field()         = string() 
value()         = string() 
body()          = string() | binary() 
filename()      = string() 
    

Some type definitions relevant when using https, for details ssl(3):

ssl_options() = {verify,     code()}   | 
                {depth,      depth()}  | 
                {certfile,   path()}   | 
                {keyfile,    path()}   | 
                {password,   string()} | 
                {cacertfile, path()}   | 
                {ciphers,    string()} 
    

A HTTP client can be configured to start when starting the inets application or started dynamically in runtime by calling the inets application API inets:start(httpc, ServiceConfig), or inets:start(httpc, ServiceConfig, How) see inets(3) Below follows a description of the available configuration options.

{profile, profile()}

Name of the profile, see common data types below, this option is mandatory.

{data_dir, path()}

Directory where the profile may save persistent data, if omitted all cookies will be treated as session cookies.

The client can be stopped using inets:stop(httpc, Pid) or inets:stop(httpc, Profile).

Types:

Cancels an asynchronous HTTP-request.

Types:

Equivalent to http:request(get, {Url, []}, [], []).

Types:

Sends a HTTP-request. The function can be both synchronous and asynchronous. In the later case the function will return {ok, RequestId} and later on message(s) will be sent to the calling process on the format:

          {http, {RequestId, Result}}
          {http, {RequestId, {error, Reason}}}
          {http, {RequestId, stream_start, Headers}
          {http, {RequestId, stream, BinBodyPart}
          {http, {RequestId, stream_end, Headers}
          {http, {RequestId, saved_to_file}}.

Http option (http_option()) details:

timeout

Timeout time for the request.

Defaults to infinity.

connect_timeout

Connection timeout time, used during the initial request, when the client is connecting to the server.

Defaults to the value of the timeout option.

ssl

If using SSL, these SSL-specific options are used.

Defaults to [].

autoredirect

Should the client automatically retreive the information from the new URI and return that as the result instead of a 30X-result code.

Note that for some 30X-result codes automatic redirect is not allowed in these cases the 30X-result will always be returned.

Defaults to true.

proxy_auth

A proxy-authorization header using the provided user name and password will be added to the request.

version

Can be used to make the client act as an HTTP/1.0 or HTTP/0.9 client. By default this is an HTTP/1.1 client. When using HTTP/1.0 persistent connections will not be used.

Defaults to the trsing "HTTP/1.1".

relaxed

If set to true workarounds for known server deviations from the HTTP-standard are enabled.

Defaults to false.

Option (option()) details:

sync

Shall the request be synchronous or asynchronous.

Defaults to true.

stream

Streams the body of a 200 or 206 response to the calling process or to a file. When streaming to the calling process using the option self the the following stream messages will be sent to that process: {http, {RequestId, stream_start, Headers}, {http, {RequestId, stream, BinBodyPart}, {http, {RequestId, stream_end, Headers}. When streaming to to the calling processes using the option {self once} the first message will have an additional element e.i. {http, {RequestId, stream_start, Headers, Pid}, this is the process id that should be used as an argument to http:stream_next/1 to trigger the next message to be sent to the calling process.

Note that it is possible that chunked encoding will add headers so that there are more headers in the stream_end message than in the stream_start. When streaming to a file and the request is asynchronous the message {http, {RequestId, saved_to_file}} will be sent.

Defaults to none.

body_format

Defines if the body shall be delivered as a string or as a binary. This option is only valid for the synchronous request.

Defaults to string.

full_result

Should a "full result" be returned to the caller (that is, the body, the headers and the entire status-line) or not (the body and the status code).

Defaults to true.

header_as_is

Shall the headers provided by the user be made lower case or be regarded as case sensitive.

Note that the http standard requires them to be case insenstive. This feature should only be used if there is no other way to communicate with the server or for testing purpose. Also note that when this option is used no headers will be automatically added, all necessary headers has to be provided by the user.

Defaults to false.

Types:

Sets options to be used for subsequent requests.

Types:

Triggers the next message to be streamed, e.i. same behavior as active once for sockets.

Types:

Saves the cookies defined in SetCookieHeaders in the client profile's cookie database. You need to call this function if you set the option cookies to verify. If no profile is specified the default profile will be used.

Types:

Returns the cookie header that would be sent when making a request to Url using the profile Profile. If no profile is specified the default profile will be used.

RFC 2616, inets(3), ssl(3)