WARNING THIS PAGE IS IN PROGRESS, AS IT IS NOW, IT NEEDS UPDATE SINCE IT DOES NOT REFLECT THE FUTURE INTERFACE
This specification is a proposition based on recent discussion on the mailing list. This is work in progress, so far nothing had been decided. You can find another proposal at http://eiffel.seibostudios.se/wiki/EWSGI , it has common background and goal, however still differ on specific parts. The main goal for now is to unified those 2 specifications.
Note the following is work in progress, and reflect a specification proposal, rather than the final specification.
For now, the specification from EWF is done in Eiffel interface please see: https://github.com/Eiffel-World/Eiffel-Web-Framework/tree/master/library/server/ewsgi/specification
WGI_APPLICATION
deferred class
WGI_APPLICATION
feature {NONE} -- Execution
execute (req: WGI_REQUEST; res: WGI_RESPONSE_BUFFER)
-- Execute the request
-- See `req.input' for input stream
-- `req.meta_variables' for the CGI meta variable
-- and `res' for the output buffer
require
res_status_unset: not res.status_is_set
deferred
ensure
res_status_set: res.status_is_set
end
end
WGI_REQUEST
deferred class
WGI_REQUEST
feature -- Access: Input
input: WGI_INPUT_STREAM
-- Server input channel
deferred
end
feature -- Access: extra values
request_time: detachable DATE_TIME
-- Request time (UTC)
deferred
end
feature -- Access: CGI meta variables
meta_variable (a_name: READABLE_STRING_GENERAL): detachable WGI_VALUE
-- Environment variable related to `a_name'
require
a_name_valid: a_name /= Void and then not a_name.is_empty
deferred
end
meta_string_variable (a_name: READABLE_STRING_GENERAL): detachable READABLE_STRING_32
-- Environment variable related to `a_name'
require
a_name_valid: a_name /= Void and then not a_name.is_empty
do
if attached meta_variable (a_name) as val then
Result := val.as_string
end
end
meta_variables: ITERABLE [WGI_VALUE]
-- These variables are specific to requests made with HTTP.
-- Interpretation of these variables may depend on the value of
-- SERVER_PROTOCOL.
--
-- Environment variables with names beginning with "HTTP_" contain
-- header data read from the client, if the protocol used was HTTP.
-- The HTTP header name is converted to upper case, has all
-- occurrences of "-" replaced with "_" and has "HTTP_" prepended to
-- give the environment variable name. The header data may be
-- presented as sent by the client, or may be rewritten in ways which
-- do not change its semantics. If multiple headers with the same
-- field-name are received then they must be rewritten as a single
-- header having the same semantics. Similarly, a header that is
-- received on more than one line must be merged onto a single line.
-- The server must, if necessary, change the representation of the
-- data (for example, the character set) to be appropriate for a CGI
-- environment variable.
--
-- The server is not required to create environment variables for all
-- the headers that it receives. In particular, it may remove any
-- headers carrying authentication information, such as
-- "Authorization"; it may remove headers whose value is available to
-- the script via other variables, such as "Content-Length" and
-- "Content-Type".
--
-- For convenience it might also include the following CGI entries
deferred
end
feature -- Common Gateway Interface - 1.1 8 January 1996
auth_type: detachable READABLE_STRING_32
-- This variable is specific to requests made via the "http"
-- scheme.
--
-- If the Script-URI required access authentication for external
-- access, then the server MUST set the value of this variable
-- from the 'auth-scheme' token in the request's "Authorization"
-- header field. Otherwise it is set to NULL.
--
-- AUTH_TYPE = "" | auth-scheme
-- auth-scheme = "Basic" | "Digest" | token
--
-- HTTP access authentication schemes are described in section 11
-- of the HTTP/1.1 specification [8]. The auth-scheme is not
-- case-sensitive.
--
-- Servers MUST provide this metavariable to scripts if the
-- request header included an "Authorization" field that was
-- authenticated.
deferred
end
content_length: detachable READABLE_STRING_32
-- This metavariable is set to the size of the message-body
-- entity attached to the request, if any, in decimal number of
-- octets. If no data are attached, then this metavariable is
-- either NULL or not defined. The syntax is the same as for the
-- HTTP "Content-Length" header field (section 14.14, HTTP/1.1
-- specification [8]).
--
-- CONTENT_LENGTH = "" | 1*digit
--
-- Servers MUST provide this metavariable to scripts if the
-- request was accompanied by a message-body entity.
deferred
end
content_length_value: NATURAL_64
-- Integer value related to `content_length"
deferred
end
content_type: detachable READABLE_STRING_32
-- If the request includes a message-body, CONTENT_TYPE is set to
-- the Internet Media Type [9] of the attached entity if the type
-- was provided via a "Content-type" field in the request header,
-- or if the server can determine it in the absence of a supplied
-- "Content-type" field. The syntax is the same as for the HTTP
-- "Content-Type" header field.
--
-- CONTENT_TYPE = "" | media-type
-- media-type = type "/" subtype *( ";" parameter)
-- type = token
-- subtype = token
-- parameter = attribute "=" value
-- attribute = token
-- value = token | quoted-string
--
-- The type, subtype, and parameter attribute names are not
-- case-sensitive. Parameter values MAY be case sensitive. Media
-- types and their use in HTTP are described in section 3.7 of
-- the HTTP/1.1 specification [8].
--
-- Example:
--
-- application/x-www-form-urlencoded
--
-- There is no default value for this variable. If and only if it
-- is unset, then the script MAY attempt to determine the media
-- type from the data received. If the type remains unknown, then
-- the script MAY choose to either assume a content-type of
-- application/octet-stream or reject the request with a 415
-- ("Unsupported Media Type") error. See section 7.2.1.3 for more
-- information about returning error status values.
--
-- Servers MUST provide this metavariable to scripts if a
-- "Content-Type" field was present in the original request
-- header. If the server receives a request with an attached
-- entity but no "Content-Type" header field, it MAY attempt to
-- determine the correct datatype, or it MAY omit this
-- metavariable when communicating the request information to the
-- script.
deferred
end
gateway_interface: READABLE_STRING_32
-- This metavariable is set to the dialect of CGI being used by
-- the server to communicate with the script. Syntax:
--
-- GATEWAY_INTERFACE = "CGI" "/" major "." minor
-- major = 1*digit
-- minor = 1*digit
--
-- Note that the major and minor numbers are treated as separate
-- integers and hence each may be more than a single digit. Thus
-- CGI/2.4 is a lower version than CGI/2.13 which in turn is
-- lower than CGI/12.3. Leading zeros in either the major or the
-- minor number MUST be ignored by scripts and SHOULD NOT be
-- generated by servers.
--
-- This document defines the 1.1 version of the CGI interface
-- ("CGI/1.1").
--
-- Servers MUST provide this metavariable to scripts.
--
-- The version of the CGI specification to which this server
-- complies. Syntax:
--
-- GATEWAY_INTERFACE = "CGI" "/" 1*digit "." 1*digit
--
-- Note that the major and minor numbers are treated as separate
-- integers and that each may be incremented higher than a single
-- digit. Thus CGI/2.4 is a lower version than CGI/2.13 which in
-- turn is lower than CGI/12.3. Leading zeros must be ignored by
-- scripts and should never be generated by servers.
deferred
end
path_info: READABLE_STRING_32
-- The PATH_INFO metavariable specifies a path to be interpreted
-- by the CGI script. It identifies the resource or sub-resource
-- to be returned by the CGI script, and it is derived from the
-- portion of the URI path following the script name but
-- preceding any query data. The syntax and semantics are similar
-- to a decoded HTTP URL 'path' token (defined in RFC 2396 [4]),
-- with the exception that a PATH_INFO of "/" represents a single
-- void path segment.
--
-- PATH_INFO = "" | ( "/" path )
-- path = segment *( "/" segment )
-- segment = *pchar
-- pchar = <any CHAR except "/">
--
-- The PATH_INFO string is the trailing part of the <path>
-- component of the Script-URI (see section 3.2) that follows the
-- SCRIPT_NAME portion of the path.
--
-- Servers MAY impose their own restrictions and limitations on
-- what values they will accept for PATH_INFO, and MAY reject or
-- edit any values they consider objectionable before passing
-- them to the script.
--
-- Servers MUST make this URI component available to CGI scripts.
-- The PATH_INFO value is case-sensitive, and the server MUST
-- preserve the case of the PATH_INFO element of the URI when
-- making it available to scripts.
deferred
end
path_translated: detachable READABLE_STRING_32
-- PATH_TRANSLATED is derived by taking any path-info component
-- of the request URI (see section 6.1.6), decoding it (see
-- section 3.1), parsing it as a URI in its own right, and
-- performing any virtual-to-physical translation appropriate to
-- map it onto the server's document repository structure. If the
-- request URI includes no path-info component, the
-- PATH_TRANSLATED metavariable SHOULD NOT be defined.
--
--
-- PATH_TRANSLATED = *CHAR
--
-- For a request such as the following:
--
-- http://somehost.com/cgi-bin/somescript/this%2eis%2epath%2einfo
--
-- the PATH_INFO component would be decoded, and the result
-- parsed as though it were a request for the following:
--
-- http://somehost.com/this.is.the.path.info
--
-- This would then be translated to a location in the server's
-- document repository, perhaps a filesystem path something like
-- this:
--
-- /usr/local/www/htdocs/this.is.the.path.info
--
-- The result of the translation is the value of PATH_TRANSLATED.
--
-- The value of PATH_TRANSLATED may or may not map to a valid
-- repository location. Servers MUST preserve the case of the
-- path-info segment if and only if the underlying repository
-- supports case-sensitive names. If the repository is only
-- case-aware, case-preserving, or case-blind with regard to
-- document names, servers are not required to preserve the case
-- of the original segment through the translation.
--
-- The translation algorithm the server uses to derive
-- PATH_TRANSLATED is implementation defined; CGI scripts which
-- use this variable may suffer limited portability.
--
-- Servers SHOULD provide this metavariable to scripts if and
-- only if the request URI includes a path-info component.
deferred
end
query_string: READABLE_STRING_32
-- A URL-encoded string; the <query> part of the Script-URI. (See
-- section 3.2.)
--
-- QUERY_STRING = query-string
-- query-string = *uric
-- The URL syntax for a query string is described in section 3 of
-- RFC 2396 [4].
--
-- Servers MUST supply this value to scripts. The QUERY_STRING
-- value is case-sensitive. If the Script-URI does not include a
-- query component, the QUERY_STRING metavariable MUST be defined
-- as an empty string ("").
deferred
end
remote_addr: READABLE_STRING_32
-- The IP address of the client sending the request to the
-- server. This is not necessarily that of the user agent (such
-- as if the request came through a proxy).
--
-- REMOTE_ADDR = hostnumber
-- hostnumber = ipv4-address | ipv6-address
-- The definitions of ipv4-address and ipv6-address are provided
-- in Appendix B of RFC 2373 [13].
--
-- Servers MUST supply this value to scripts.
deferred
end
remote_host: detachable READABLE_STRING_32
-- The fully qualified domain name of the client sending the
-- request to the server, if available, otherwise NULL. (See
-- section 6.1.9.) Fully qualified domain names take the form as
-- described in section 3.5 of RFC 1034 [10] and section 2.1 of
-- RFC 1123 [5]. Domain names are not case sensitive.
--
-- Servers SHOULD provide this information to scripts.
deferred
end
remote_ident: detachable READABLE_STRING_32
-- The identity information reported about the connection by a
-- RFC 1413 [11] request to the remote agent, if available.
-- Servers MAY choose not to support this feature, or not to
-- request the data for efficiency reasons.
--
-- REMOTE_IDENT = *CHAR
--
-- The data returned may be used for authentication purposes, but
-- the level of trust reposed in them should be minimal.
--
-- Servers MAY supply this information to scripts if the RFC1413
-- [11] lookup is performed.
deferred
end
remote_user: detachable READABLE_STRING_32
-- If the request required authentication using the "Basic"
-- mechanism (i.e., the AUTH_TYPE metavariable is set to
-- "Basic"), then the value of the REMOTE_USER metavariable is
-- set to the user-ID supplied. In all other cases the value of
-- this metavariable is undefined.
--
-- REMOTE_USER = *OCTET
--
-- This variable is specific to requests made via the HTTP
-- protocol.
--
-- Servers SHOULD provide this metavariable to scripts.
deferred
end
request_method: READABLE_STRING_32
-- The REQUEST_METHOD metavariable is set to the method with
-- which the request was made, as described in section 5.1.1 of
-- the HTTP/1.0 specification [3] and section 5.1.1 of the
-- HTTP/1.1 specification [8].
--
-- REQUEST_METHOD = http-method
-- http-method = "GET" | "HEAD" | "POST" | "PUT" | "DELETE"
-- | "OPTIONS" | "TRACE" | extension-method
-- extension-method = token
--
-- The method is case sensitive. CGI/1.1 servers MAY choose to
-- process some methods directly rather than passing them to
-- scripts.
--
-- This variable is specific to requests made with HTTP.
--
-- Servers MUST provide this metavariable to scripts.
deferred
end
script_name: READABLE_STRING_32
-- The SCRIPT_NAME metavariable is set to a URL path that could
-- identify the CGI script (rather than the script's output). The
-- syntax and semantics are identical to a decoded HTTP URL
-- 'path' token (see RFC 2396 [4]).
--
-- SCRIPT_NAME = "" | ( "/" [ path ] )
--
-- The SCRIPT_NAME string is some leading part of the <path>
-- component of the Script-URI derived in some implementation
-- defined manner. No PATH_INFO or QUERY_STRING segments (see
-- sections 6.1.6 and 6.1.8) are included in the SCRIPT_NAME
-- value.
--
-- Servers MUST provide this metavariable to scripts.
deferred
end
server_name: READABLE_STRING_32
-- The SERVER_NAME metavariable is set to the name of the server,
-- as derived from the <host> part of the Script-URI (see section
-- 3.2).
--
-- SERVER_NAME = hostname | hostnumber
--
-- Servers MUST provide this metavariable to scripts.
deferred
end
server_port: INTEGER_32
-- The SERVER_PORT metavariable is set to the port on which the
-- request was received, as used in the <port> part of the
-- Script-URI.
--
-- SERVER_PORT = 1*digit
--
-- If the <port> portion of the script-URI is blank, the actual
-- port number upon which the request was received MUST be
-- supplied.
--
-- Servers MUST provide this metavariable to scripts.
deferred
end
server_protocol: READABLE_STRING_32
-- The SERVER_PROTOCOL metavariable is set to the name and
-- revision of the information protocol with which the request
-- arrived. This is not necessarily the same as the protocol
-- version used by the server in its response to the client.
--
-- SERVER_PROTOCOL = HTTP-Version | extension-version
-- | extension-token
-- HTTP-Version = "HTTP" "/" 1*digit "." 1*digit
-- extension-version = protocol "/" 1*digit "." 1*digit
-- protocol = 1*( alpha | digit | "+" | "-" | "." )
-- extension-token = token
--
-- 'protocol' is a version of the <scheme> part of the
-- Script-URI, but is not identical to it. For example, the
-- scheme of a request may be "https" while the protocol remains
-- "http". The protocol is not case sensitive, but by convention,
-- 'protocol' is in upper case.
--
-- A well-known extension token value is "INCLUDED", which
-- signals that the current document is being included as part of
-- a composite document, rather than being the direct target of
-- the client request.
--
-- Servers MUST provide this metavariable to scripts.
deferred
end
server_software: READABLE_STRING_32
-- The SERVER_SOFTWARE metavariable is set to the name and
-- version of the information server software answering the
-- request (and running the gateway).
--
-- SERVER_SOFTWARE = 1*product
-- product = token [ "/" product-version ]
-- product-version = token
-- Servers MUST provide this metavariable to scripts.
deferred
end
feature -- HTTP_*
http_accept: detachable READABLE_STRING_32
-- Contents of the Accept: header from the current request, if there is one.
-- Example: 'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8'
deferred
end
http_accept_charset: detachable READABLE_STRING_32
-- Contents of the Accept-Charset: header from the current request, if there is one.
-- Example: 'iso-8859-1,*,utf-8'.
deferred
end
http_accept_encoding: detachable READABLE_STRING_32
-- Contents of the Accept-Encoding: header from the current request, if there is one.
-- Example: 'gzip'.
deferred
end
http_accept_language: detachable READABLE_STRING_32
-- Contents of the Accept-Language: header from the current request, if there is one.
-- Example: 'en'.
deferred
end
http_connection: detachable READABLE_STRING_32
-- Contents of the Connection: header from the current request, if there is one.
-- Example: 'Keep-Alive'.
deferred
end
http_host: detachable READABLE_STRING_32
-- Contents of the Host: header from the current request, if there is one.
deferred
end
http_referer: detachable READABLE_STRING_32
-- The address of the page (if any) which referred the user agent to the current page.
-- This is set by the user agent.
-- Not all user agents will set this, and some provide the ability to modify HTTP_REFERER as a feature.
-- In short, it cannot really be trusted.
deferred
end
http_user_agent: detachable READABLE_STRING_32
-- Contents of the User-Agent: header from the current request, if there is one.
-- This is a string denoting the user agent being which is accessing the page.
-- A typical example is: Mozilla/4.5 [en] (X11; U; Linux 2.2.9 i586).
-- Among other things, you can use this value to tailor your page's
-- output to the capabilities of the user agent.
deferred
end
http_authorization: detachable READABLE_STRING_32
-- Contents of the Authorization: header from the current request, if there is one.
deferred
end
feature -- Extra CGI environment variables
request_uri: READABLE_STRING_32
-- The URI which was given in order to access this page; for instance, '/index.html'.
deferred
end
orig_path_info: detachable READABLE_STRING_32
-- Original version of path_info before processed by Current environment
deferred
end
feature -- Query string Parameters
query_parameters: ITERABLE [WGI_VALUE]
-- Variables extracted from QUERY_STRING
deferred
end
query_parameter (a_name: READABLE_STRING_GENERAL): detachable WGI_VALUE
-- Parameter for name `n'.
require
a_name_valid: a_name /= Void and then not a_name.is_empty
deferred
end
feature -- Form fields and related
form_data_parameters: ITERABLE [WGI_VALUE]
-- Variables sent by POST request
deferred
end
form_data_parameter (a_name: READABLE_STRING_GENERAL): detachable WGI_VALUE
-- Field for name `a_name'.
require
a_name_valid: a_name /= Void and then not a_name.is_empty
deferred
end
uploaded_files: HASH_TABLE [WGI_UPLOADED_FILE_DATA, READABLE_STRING_GENERAL]
-- Table of uploaded files information
deferred
end
feature -- Cookies
cookies: ITERABLE [WGI_VALUE]
-- Expanded cookies variable
deferred
end
cookie (a_name: READABLE_STRING_GENERAL): detachable WGI_VALUE
-- Field for name `a_name'.
require
a_name_valid: a_name /= Void and then not a_name.is_empty
deferred
end
feature -- Access: all variables
items: ITERABLE [WGI_VALUE]
-- Table containing all the various variables
-- Warning: this is computed each time, if you change the content of other containers
-- this won't update this Result's content, unless you query it again
deferred
end
item (a_name: READABLE_STRING_GENERAL): detachable WGI_VALUE
-- Variable named `a_name' from any of the variables container
-- and following a specific order
-- execution, environment, get, post, cookies
require
a_name_valid: a_name /= Void and then not a_name.is_empty
deferred
end
feature -- Uploaded File Handling
is_uploaded_file (a_filename: READABLE_STRING_GENERAL): BOOLEAN
-- Is `a_filename' a file uploaded via HTTP POST
deferred
end
feature -- URL Utility
absolute_script_url (a_path: STRING_8): STRING_8
-- Absolute Url for the script if any, extended by `a_path'
deferred
end
script_url (a_path: STRING_8): STRING_8
-- Url relative to script name if any, extended by `a_path'
require
a_path_attached: a_path /= Void
deferred
end
invariant
server_name_not_empty: not server_name.is_empty
server_port_set: server_port /= 0
request_method_attached: request_method /= Void
path_info_attached: path_info /= Void
query_string_attached: query_string /= Void
remote_addr_attached: remote_addr /= Void
same_orig_path_info: orig_path_info ~ meta_string_variable ({WGI_META_NAMES}.orig_path_info)
same_path_info: path_info ~ meta_string_variable ({WGI_META_NAMES}.path_info)
path_info_identical: path_info ~ meta_string_variable ({WGI_META_NAMES}.path_info)
end
WGI_RESPONSE_BUFFER
deferred class
WGI_RESPONSE_BUFFER
feature {WGI_APPLICATION} -- Commit
commit
-- Commit the current response
deferred
ensure
status_is_set: status_is_set
header_committed: header_committed
message_committed: message_committed
end
feature -- Status report
header_committed: BOOLEAN
-- Header committed?
deferred
end
message_committed: BOOLEAN
-- Message committed?
deferred
end
message_writable: BOOLEAN
-- Can message be written?
deferred
end
feature {WGI_RESPONSE_BUFFER} -- Core output operation
write (s: READABLE_STRING_8)
-- Send the string `s'
-- this can be used for header and body
deferred
end
feature -- Status setting
status_is_set: BOOLEAN
-- Is status set?
deferred
end
set_status_code (a_code: INTEGER)
-- Set response status code
-- Should be done before sending any data back to the client
require
status_not_set: not status_is_set
header_not_committed: not header_committed
deferred
ensure
status_code_set: status_code = a_code
status_set: status_is_set
end
status_code: INTEGER
-- Response status
deferred
end
feature -- Header output operation
write_headers_string (a_headers: READABLE_STRING_8)
require
status_set: status_is_set
header_not_committed: not header_committed
deferred
ensure
status_set: status_is_set
header_committed: header_committed
message_writable: message_writable
end
write_header (a_status_code: INTEGER; a_headers: detachable ARRAY [TUPLE [key: READABLE_STRING_8; value: READABLE_STRING_8]])
-- Send headers with status `a_status', and headers from `a_headers'
require
status_not_set: not status_is_set
header_not_committed: not header_committed
deferred
ensure
header_committed: header_committed
status_set: status_is_set
message_writable: message_writable
end
feature -- Output operation
write_string (s: READABLE_STRING_8)
-- Send the string `s'
require
message_writable: message_writable
deferred
end
write_substring (s: READABLE_STRING_8; a_begin_index, a_end_index: INTEGER)
-- Send the substring `s[a_begin_index:a_end_index]'
require
message_writable: message_writable
deferred
end
write_file_content (fn: READABLE_STRING_8)
-- Send the content of file `fn'
require
message_writable: message_writable
deferred
end
flush
-- Flush if it makes sense
deferred
end
end