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Partially update manual for the cowboy_req
Only the access functions have been modified so far.
This commit is contained in:
Loïc Hoguin
parent
8fe700f341
commit
faca7866ed
16 changed files with 1409 additions and 895 deletions
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@ -6,685 +6,188 @@ cowboy_req - HTTP request and response
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== Description
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The `cowboy_req` module provides functions to access, manipulate
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The module `cowboy_req` provides functions to access, manipulate
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and respond to requests.
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The functions in this module follow patterns for their return types,
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based on the kind of function.
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There are four types of functions in this module. They can be
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differentiated by their name and their return type:
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* access: `Value`
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* action: `ok | {Result, Req} | {Result, Value, Req}`
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* modification: `Req`
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* question: `boolean()`
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[options="header"]
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|===
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| Type | Name pattern | Return type
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| access | no verb, parse_*, match_* | `Value`
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| question | has_* | `boolean()`
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| modification | set_* | `Req`
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| action | any other verb | `ok \| {Result, Value, Req}`
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|===
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Whenever `Req` is returned, you must use this returned value and
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ignore any previous you may have had. This value contains various
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values which are necessary for Cowboy to keep track of the request
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and response states.
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Any `Req` returned must be used in place of the one passed as
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argument. Functions that perform an action in particular write
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state in the Req object to make sure you are using the function
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correctly. For example, it's only possible to send one response,
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and to read the body once.
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All functions which perform an action should only be called once.
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This includes reading the request body or replying. Cowboy will
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throw an error on the second call when it detects suspicious behavior.
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== Exports
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It is highly discouraged to pass the Req object to another process.
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Doing so and calling `cowboy_req` functions from it leads to
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undefined behavior.
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Raw request:
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* link:man:cowboy_req:method(3)[cowboy_req:method(3)] - HTTP method
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* link:man:cowboy_req:version(3)[cowboy_req:version(3)] - HTTP version
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* link:man:cowboy_req:scheme(3)[cowboy_req:scheme(3)] - URI scheme
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* link:man:cowboy_req:host(3)[cowboy_req:host(3)] - URI host name
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* link:man:cowboy_req:port(3)[cowboy_req:port(3)] - URI port number
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* link:man:cowboy_req:path(3)[cowboy_req:path(3)] - URI path
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* link:man:cowboy_req:qs(3)[cowboy_req:qs(3)] - URI query string
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* link:man:cowboy_req:uri(3)[cowboy_req:uri(3)] - Reconstructed URI
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* link:man:cowboy_req:header(3)[cowboy_req:header(3)] - HTTP header
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* link:man:cowboy_req:headers(3)[cowboy_req:headers(3)] - HTTP headers
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* link:man:cowboy_req:peer(3)[cowboy_req:peer(3)] - Peer address and port
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Processed request:
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* link:man:cowboy_req:parse_qs(3)[cowboy_req:parse_qs(3)] - Parse the query string
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* link:man:cowboy_req:match_qs(3)[cowboy_req:match_qs(3)] - Match the query string against constraints
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* link:man:cowboy_req:parse_header(3)[cowboy_req:parse_header(3)] - Parse the given HTTP header
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* link:man:cowboy_req:parse_cookies(3)[cowboy_req:parse_cookies(3)] - Parse cookie headers
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* link:man:cowboy_req:match_cookies(3)[cowboy_req:match_cookies(3)] - Match cookies against constraints
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* link:man:cowboy_req:binding(3)[cowboy_req:binding(3)] - Access a value bound from the route
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* link:man:cowboy_req:bindings(3)[cowboy_req:bindings(3)] - Access all values bound from the route
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* link:man:cowboy_req:host_info(3)[cowboy_req:host_info(3)] - Access the route's heading host segments
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* link:man:cowboy_req:path_info(3)[cowboy_req:path_info(3)] - Access the route's trailing path segments
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Request body:
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* link:man:cowboy_req:has_body(3)[cowboy_req:has_body(3)] - Is there a request body?
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* link:man:cowboy_req:body_length(3)[cowboy_req:body_length(3)] - Body length
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* link:man:cowboy_req:read_body(3)[cowboy_req:read_body(3)] - Read the request body
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* link:man:cowboy_req:read_urlencoded_body(3)[cowboy_req:read_urlencoded_body(3)] - Read and parse a urlencoded request body
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* link:man:cowboy_req:read_part(3)[cowboy_req:read_part(3)] - Read the next part of a multipart body
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* link:man:cowboy_req:read_part_body(3)[cowboy_req:read_part_body(3)] - Read the current part's body in a multipart body
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Response:
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* link:man:cowboy_req:set_resp_cookie(3)[cowboy_req:set_resp_cookie(3)] - Set a cookie
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* link:man:cowboy_req:set_resp_header(3)[cowboy_req:set_resp_header(3)] - Set a response header
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* link:man:cowboy_req:has_resp_header(3)[cowboy_req:has_resp_header(3)] - Is the given response header set?
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* link:man:cowboy_req:delete_resp_header(3)[cowboy_req:delete_resp_header(3)] - Delete a response header
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* link:man:cowboy_req:set_resp_body(3)[cowboy_req:set_resp_body(3)] - Set the response body
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* link:man:cowboy_req:has_resp_body(3)[cowboy_req:has_resp_body(3)] - Is there a response body?
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* link:man:cowboy_req:reply(3)[cowboy_req:reply(3)] - Send the response
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* link:man:cowboy_req:stream_reply(3)[cowboy_req:stream_reply(3)] - Send the response and stream its body
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* link:man:cowboy_req:stream_body(3)[cowboy_req:stream_body(3)] - Send a chunk of the response body
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* link:man:cowboy_req:push(3)[cowboy_req:push(3)] - Push a resource to the client
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== Types
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=== body_opts() = [Option]
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=== push_opts()
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[source,erlang]
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----
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Option = {continue, boolean()}
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| {length, non_neg_integer()}
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| {read_length, non_neg_integer()}
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| {read_timeout, timeout()}
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| {transfer_decode, transfer_decode_fun(), any()}
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| {content_decode, content_decode_fun()}
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push_opts() :: #{
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method => binary(), %% case sensitive
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scheme => binary(), %% lowercase; case insensitive
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host => binary(), %% lowercase; case insensitive
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port => inet:port_number(),
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qs => binary() %% case sensitive
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}
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----
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Request body reading options.
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Push options.
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=== cookie_opts() = [Option]
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By default, Cowboy will use the GET method, an empty query string,
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and take the scheme, host and port directly from the current
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request's URI.
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=== read_body_opts()
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[source,erlang]
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----
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Option = {max_age, non_neg_integer()}
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| {domain, binary()}
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| {path, binary()}
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| {secure, boolean()}
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| {http_only, boolean()}
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read_body_opts() :: #{
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length => non_neg_integer(),
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period => non_neg_integer(),
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timeout => timeout()
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}
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----
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Cookie options.
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Body reading options.
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=== req() - opaque to the user
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The defaults are function-specific.
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=== req()
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[source,erlang]
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----
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req() :: #{
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method := binary(), %% case sensitive
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version := cowboy:http_version() | atom(),
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scheme := binary(), %% lowercase; case insensitive
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host := binary(), %% lowercase; case insensitive
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port := inet:port_number(),
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path := binary(), %% case sensitive
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qs := binary(), %% case sensitive
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headers := cowboy:http_headers(),
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peer := {inet:ip_address(), inet:port_number()}
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}
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----
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The Req object.
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All functions in this module receive a `Req` as argument,
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and some of them return a new object labelled `Req2` in
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the function descriptions below.
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Contains information about the request and response. While
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some fields are publicly documented, others aren't and shouldn't
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be used.
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== Request related exports
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You may add custom fields if required. Make sure to namespace
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them by prepending an underscore and the name of your application:
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=== binding(Name, Req) -> binding(Name, Req, undefined)
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.Setting a custom field
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[source,erlang]
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----
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Req#{_myapp_auth_method => pubkey}.
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----
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Alias of `cowboy_req:binding/3`.
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=== resp_body()
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=== binding(Name, Req, Default) -> Value
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[source,erlang]
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----
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resp_body() :: iodata()
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| {sendfile, Offset, Length, Filename}
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Name = atom():: Binding name.
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Default = any():: Default value.
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Value = any() | Default:: Binding value.
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Offset :: non_neg_integer()
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Length :: pos_integer()
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Filename :: file:name_all()
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----
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Return the value for the given binding.
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Response body.
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By default the value is a binary, however constraints may change
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the type of this value (for example automatically converting
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numbers to integer).
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It can take two forms: the actual data to be sent or a
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tuple indicating which file to send.
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=== bindings(Req) -> [{Name, Value}]
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When sending data directly, the type is either a binary or
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an iolist. Iolists are an efficient way to build output.
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Instead of concatenating strings or binaries, you can simply
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build a list containing the fragments you want to send in the
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order they should be sent:
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Name = atom():: Binding name.
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Value = any():: Binding value.
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.Example iolists usage
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[source,erlang]
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----
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1> RespBody = ["Hello ", [<<"world">>, $!]].
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["Hello ",[<<"world">>,33]]
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2> io:format("~s~n", [RespBody]).
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Hello world!
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----
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Return all bindings.
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When using the sendfile tuple, the `Length` value is mandatory
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and must be higher than 0. It is sent with the response in the
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content-length header.
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By default the value is a binary, however constraints may change
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the type of this value (for example automatically converting
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numbers to integer).
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// @todo Make sure we have a test with an empty file...
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// @todo cowboy_static should probably NOT return a sendfile tuple if size is 0.
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=== header(Name, Req) -> header(Name, Req, undefined)
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//%% While sendfile allows a Len of 0 that means "everything past Offset",
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//%% Cowboy expects the real length as it is used as metadata.
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//%% @todo We should probably explicitly reject it.
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Alias of `cowboy_req:header/3`.
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== See also
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=== header(Name, Req, Default) -> Value
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Name = binary():: Request header name.
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Default = any():: Default value.
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Value = binary() | Default:: Request header value.
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Return the value for the given header.
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While header names are case insensitive, this function expects
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the name to be a lowercase binary.
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=== headers(Req) -> Headers
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Headers = cowboy:http_headers():: Request headers.
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Return all headers.
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=== host(Req) -> Host
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Host = binary():: Requested host.
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Return the requested host.
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=== host_info(Req) -> HostInfo
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HostInfo = cowboy_router:tokens() | undefined:: Extra tokens for the host.
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Return the extra tokens from matching against `...` during routing.
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=== host_url(Req) -> HostURL
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HostURL = binary() | undefined:: Requested URL, without the path component.
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Return the requested URL excluding the path component.
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This function will always return `undefined` until the
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`cowboy_router` middleware has been executed.
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=== match_cookies(Fields, Req) -> Map
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Fields = cowboy:fields():: Cookie fields match rules.
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Map = map():: Cookie fields matched.
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Match cookies against the given fields.
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Cowboy will only return the cookie values specified in the
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fields list, and ignore all others. Fields can be either
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the name of the cookie requested; the name along with a
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list of constraints; or the name, a list of constraints
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and a default value in case the cookie is missing.
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This function will crash if the cookie is missing and no
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default value is provided. This function will also crash
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if a constraint fails.
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The name of the cookie must be provided as an atom. The
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key of the returned map will be that atom. The value may
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be converted through the use of constraints, making this
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function able to extract, validate and convert values all
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in one step.
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=== match_qs(Fields, Req) -> Map
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Fields = cowboy:fields():: Query string fields match rules.
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Map = map():: Query string fields matched.
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Match the query string against the given fields.
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Cowboy will only return the query string values specified
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in the fields list, and ignore all others. Fields can be
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either the key requested; the key along with a list of
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constraints; or the key, a list of constraints and a
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default value in case the key is missing.
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This function will crash if the key is missing and no
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default value is provided. This function will also crash
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if a constraint fails.
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The key must be provided as an atom. The key of the
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returned map will be that atom. The value may be converted
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through the use of constraints, making this function able
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to extract, validate and convert values all in one step.
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=== meta(Name, Req) -> meta(Name, Req, undefined)
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Alias for `cowboy_req:meta/3`.
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=== meta(Name, Req, Default) -> Value
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Name = atom():: Metadata name.
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Default = any():: Default value.
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Value = any():: Metadata value.
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Return metadata about the request.
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=== method(Req) -> Method
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Method = binary():: Request method.
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Return the method.
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Methods are case sensitive. Standard methods are always uppercase.
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=== parse_cookies(Req) -> [{Name, Value}]
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Name = binary():: Cookie name.
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Value = binary():: Cookie value.
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Parse and return all cookies.
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Cookie names are case sensitive.
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=== parse_header(Name, Req) -> see below
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Alias of `cowboy_req:parse_header/3`.
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The `parse_header/2` function will call `parser_header/3` with a
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different default value depending on the header being parsed. The
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following table summarizes the default values used.
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[cols="<,^",options="header"]
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|===
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| Header name | Header value
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| content-length | `0`
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| cookie | `[]`
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| transfer-encoding | `[<<"identity">>]`
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| Any other header | `undefined`
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|===
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=== parse_header(Name, Req, Default) -> ParsedValue | Default
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Name = binary():: Request header name.
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Default = any():: Default value.
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ParsedValue - see below:: Parsed request header value.
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Parse the given header.
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While header names are case insensitive, this function expects
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the name to be a lowercase binary.
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The parsed value differs depending on the header being parsed. The
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following table summarizes the different types returned.
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[cols="<,^",options="header"]
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|===
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| Header name | Type of parsed header value
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| accept | `[{{Type, SubType, Params}, Quality, AcceptExt}]`
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| accept-charset | `[{Charset, Quality}]`
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| accept-encoding | `[{Encoding, Quality}]`
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| accept-language | `[{LanguageTag, Quality}]`
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| authorization | `{AuthType, Credentials}`
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| content-length | `non_neg_integer()`
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| content-type | `{Type, SubType, ContentTypeParams}`
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| cookie | `[{binary(), binary()}]`
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| expect | `[Expect \| {Expect, ExpectValue, Params}]`
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| if-match | `'*' \| [{weak \| strong, OpaqueTag}]`
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| if-modified-since | `calendar:datetime()`
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| if-none-match | `'*' \| [{weak \| strong, OpaqueTag}]`
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| if-unmodified-since | `calendar:datetime()`
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| range | `{Unit, [Range]}`
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| sec-websocket-protocol | `[binary()]`
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| transfer-encoding | `[binary()]`
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| upgrade | `[binary()]`
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| x-forwarded-for | `[binary()]`
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|===
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Types for the above table:
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* Type = SubType = Charset = Encoding = LanguageTag = binary()
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* AuthType = Expect = OpaqueTag = Unit = binary()
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* Params = ContentTypeParams = [{binary(), binary()}]
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* Quality = 0..1000
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* AcceptExt = [{binary(), binary()} | binary()]
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* Credentials - see below
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* Range = {non_neg_integer(), non_neg_integer() | infinity} | neg_integer()
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The cookie names and values, the values of the sec-websocket-protocol
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and x-forwarded-for headers, the values in `AcceptExt` and `Params`,
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the authorization `Credentials`, the `ExpectValue` and `OpaqueTag`
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are case sensitive. All values in `ContentTypeParams` are case sensitive
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except the value of the charset parameter, which is case insensitive.
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All other values are case insensitive and will be returned as lowercase.
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The headers accept, accept-encoding and cookie headers can return
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an empty list. Some other headers are expected to have a value if provided
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and may crash if the value is missing.
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The authorization header parsing code currently only supports basic
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HTTP authentication. The `Credentials` type is thus `{Username, Password}`
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with `Username` and `Password` being `binary()`.
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The range header value `Range` can take three forms:
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* `{From, To}`: from `From` to `To` units
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* `{From, infinity}`: everything after `From` units
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* `-Final`: the final `Final` units
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An `undefined` tuple will be returned if Cowboy doesn't know how
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to parse the requested header.
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=== parse_qs(Req) -> [{Name, Value}]
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Name = binary():: Query string field name.
|
||||
Value = binary() | true:: Query string field value.
|
||||
|
||||
Return the request's query string as a list of tuples.
|
||||
|
||||
The atom `true` is returned for keys which have no value.
|
||||
Keys with no value are different from keys with an empty
|
||||
value in that they do not have a `=` indicating the presence
|
||||
of a value.
|
||||
|
||||
=== path(Req) -> Path
|
||||
|
||||
Path = binary():: Requested path.
|
||||
|
||||
Return the requested path.
|
||||
|
||||
=== path_info(Req) -> PathInfo
|
||||
|
||||
PathInfo = cowboy_router:tokens() | undefined:: Extra tokens for the path.
|
||||
|
||||
Return the extra tokens from matching against `...` during routing.
|
||||
|
||||
=== peer(Req) -> Peer
|
||||
|
||||
Peer = `{inet:ip_address(), inet:port_number()}`:: Peer IP address and port number.
|
||||
|
||||
Return the client's IP address and port number.
|
||||
|
||||
=== port(Req) -> Port
|
||||
|
||||
Port = inet:port_number():: Requested port number.
|
||||
|
||||
Return the request's port.
|
||||
|
||||
The port returned by this function is obtained by parsing
|
||||
the host header. It may be different than the actual port
|
||||
the client used to connect to the Cowboy server.
|
||||
|
||||
=== qs(Req) -> QueryString
|
||||
|
||||
QueryString = binary():: Unprocessed query string.
|
||||
|
||||
Return the request's query string.
|
||||
|
||||
=== set_meta(Name, Value, Req) -> Req2
|
||||
|
||||
Name = atom():: Metadata name.
|
||||
Value = any():: Metadata value.
|
||||
|
||||
Set metadata about the request.
|
||||
|
||||
An existing value will be overwritten.
|
||||
|
||||
=== url(Req) -> URL
|
||||
|
||||
URL = binary() | undefined:: Requested URL.
|
||||
|
||||
Return the requested URL.
|
||||
|
||||
This function will always return `undefined` until the
|
||||
`cowboy_router` middleware has been executed.
|
||||
|
||||
=== version(Req) -> Version
|
||||
|
||||
Version = cowboy:http_version():: Client's advertised HTTP version.
|
||||
|
||||
Return the HTTP version used for this request.
|
||||
|
||||
== Request body related exports
|
||||
|
||||
=== body(Req) -> body(Req, [])
|
||||
|
||||
Alias of `cowboy_req:body/2`.
|
||||
|
||||
=== body(Req, Opts) -> {ok, Data, Req2} | {more, Data, Req2}
|
||||
|
||||
Opts = [body_opt()]:: Request body reading options.
|
||||
Data = binary():: Data read from the body.
|
||||
|
||||
Read the request body.
|
||||
|
||||
This function will read a chunk of the request body. If there is
|
||||
more data to be read after this function call, then a `more` tuple
|
||||
is returned. Otherwise an `ok` tuple is returned.
|
||||
|
||||
Cowboy will automatically send a `100 Continue` reply if
|
||||
required. If this behavior is not desirable, it can be disabled
|
||||
by setting the `continue` option to `false`.
|
||||
|
||||
Cowboy will by default attempt to read up to 8MB of the body,
|
||||
but in chunks of 1MB. It will use a timeout of 15s per chunk.
|
||||
All these values can be changed using the `length`, `read_length`
|
||||
and `read_timeout` options respectively. Note that the size
|
||||
of the data may not be the same as requested as the decoding
|
||||
functions may grow or shrink it, and Cowboy makes not attempt
|
||||
at returning an exact amount.
|
||||
|
||||
Cowboy will properly handle chunked transfer-encoding by
|
||||
default. If any other transfer-encoding or content-encoding
|
||||
has been used for the request, custom decoding functions
|
||||
can be used. The `content_decode` and `transfer_decode`
|
||||
options allow setting the decode functions manually.
|
||||
|
||||
After the body has been streamed fully, Cowboy will remove
|
||||
the transfer-encoding header from the Req object, and add
|
||||
the content-length header if it wasn't already there.
|
||||
|
||||
This function can only be called once. Cowboy will not cache
|
||||
the result of this call.
|
||||
|
||||
=== body_length(Req) -> Length
|
||||
|
||||
Length = non_neg_integer() | undefined:: Length of the request body.
|
||||
|
||||
Return the length of the request body.
|
||||
|
||||
The length will only be returned if the request does not
|
||||
use any transfer-encoding and if the content-length header
|
||||
is present.
|
||||
|
||||
=== body_qs(Req) -> body_qs(Req, [{length, 64000}, {read_length, 64000}, {read_timeout, 5000}])
|
||||
|
||||
Alias of `cowboy_req:body_qs/2`.
|
||||
|
||||
=== body_qs(Req, Opts) -> {ok, [{Name, Value}], Req2} | {badlength, Req2}
|
||||
|
||||
Opts = [body_opt()]:: Request body reading options.
|
||||
Name = binary():: Field name.
|
||||
Value = binary() | true:: Field value.
|
||||
|
||||
Return the request body as a list of tuples.
|
||||
|
||||
This function will parse the body assuming the content-type
|
||||
application/x-www-form-urlencoded, commonly used for the
|
||||
query string.
|
||||
|
||||
This function calls `body/2` for reading the body, with the
|
||||
same options it received. By default it will attempt to read
|
||||
a body of 64KB in one chunk, with a timeout of 5s. If the
|
||||
body is larger then a `badlength` tuple is returned.
|
||||
|
||||
This function can only be called once. Cowboy will not cache
|
||||
the result of this call.
|
||||
|
||||
=== has_body(Req) -> boolean()
|
||||
|
||||
Return whether the request has a body.
|
||||
|
||||
=== part(Req) -> part(Req, [{length, 64000}, {read_length, 64000}, {read_timeout, 5000}])
|
||||
|
||||
Alias of `cowboy_req:part/2`.
|
||||
|
||||
=== part(Req, Opts) -> {ok, Headers, Req2} | {done, Req2}
|
||||
|
||||
Opts = [body_opt()]:: Request body reading options.
|
||||
Headers = cow_multipart:headers():: Part's headers.
|
||||
|
||||
Read the headers for the next part of the multipart message.
|
||||
|
||||
Cowboy will skip any data remaining until the beginning of
|
||||
the next part. This includes the preamble to the multipart
|
||||
message but also the body of a previous part if it hasn't
|
||||
been read. Both are skipped automatically when calling this
|
||||
function.
|
||||
|
||||
The headers returned are MIME headers, NOT HTTP headers.
|
||||
They can be parsed using the functions from the `cow_multipart`
|
||||
module. In addition, the `cow_multipart:form_data/1` function
|
||||
can be used to quickly figure out `multipart/form-data` messages.
|
||||
It takes the list of headers and returns whether this part is
|
||||
a simple form field or a file being uploaded.
|
||||
|
||||
Note that once a part has been read, or skipped, it cannot
|
||||
be read again.
|
||||
|
||||
This function calls `body/2` for reading the body, with the
|
||||
same options it received. By default it will only read chunks
|
||||
of 64KB with a timeout of 5s. This is tailored for reading
|
||||
part headers, not for skipping the previous part's body.
|
||||
You might want to consider skipping large parts manually.
|
||||
|
||||
=== part_body(Req) -> part_body(Req, [])
|
||||
|
||||
Alias of `cowboy_req:part_body/2`.
|
||||
|
||||
=== part_body(Req, Opts) -> {ok, Data, Req2} | {more, Data, Req2}
|
||||
|
||||
Opts = [body_opt()]:: Request body reading options.
|
||||
Data = binary():: Part's body.
|
||||
|
||||
Read the body of the current part of the multipart message.
|
||||
|
||||
This function calls `body/2` for reading the body, with the
|
||||
same options it received. It uses the same defaults.
|
||||
|
||||
If there are more data to be read from the socket for this
|
||||
part, the function will return what it could read inside a
|
||||
`more` tuple. Otherwise, it will return an `ok` tuple.
|
||||
|
||||
Calling this function again after receiving a `more` tuple
|
||||
will return another chunk of body. The last chunk will be
|
||||
returned inside an `ok` tuple.
|
||||
|
||||
Note that once the body has been read, fully or partially,
|
||||
it cannot be read again.
|
||||
|
||||
== Response related exports
|
||||
|
||||
=== chunk(Data, Req) -> ok
|
||||
|
||||
Data = iodata():: Chunk data to be sent.
|
||||
|
||||
Send a chunk of data.
|
||||
|
||||
This function should be called as many times as needed
|
||||
to send data chunks after calling `chunked_reply/{2,3}`.
|
||||
|
||||
When the method is HEAD, no data will actually be sent.
|
||||
|
||||
If the request uses HTTP/1.0, the data is sent directly
|
||||
without wrapping it in an HTTP/1.1 chunk, providing
|
||||
compatibility with older clients.
|
||||
|
||||
=== chunked_reply(StatusCode, Req) -> chunked_reply(StatusCode, [], Req)
|
||||
|
||||
Alias of `cowboy_req:chunked_reply/3`.
|
||||
|
||||
=== chunked_reply(StatusCode, Headers, Req) -> Req2
|
||||
|
||||
StatusCode = cowboy:http_status():: Response status code.
|
||||
Headers = cowboy:http_headers():: Response headers.
|
||||
|
||||
Send a response using chunked transfer-encoding.
|
||||
|
||||
This function effectively sends the response status line
|
||||
and headers to the client.
|
||||
|
||||
This function will not send any body set previously. After
|
||||
this call the handler must use the `chunk/2` function
|
||||
repeatedly to send the body in as many chunks as needed.
|
||||
|
||||
If the request uses HTTP/1.0, the data is sent directly
|
||||
without wrapping it in an HTTP/1.1 chunk, providing
|
||||
compatibility with older clients.
|
||||
|
||||
This function can only be called once, with the exception
|
||||
of overriding the response in the `onresponse` hook.
|
||||
|
||||
=== continue(Req) -> ok
|
||||
|
||||
Send a 100 Continue intermediate reply.
|
||||
|
||||
This reply is required before the client starts sending the
|
||||
body when the request contains the `expect` header with the
|
||||
`100-continue` value.
|
||||
|
||||
Cowboy will send this automatically when required. However
|
||||
you may want to do it manually by disabling this behavior
|
||||
with the `continue` body option and then calling this
|
||||
function.
|
||||
|
||||
=== delete_resp_header(Name, Req) -> Req2
|
||||
|
||||
Name = binary():: Response header name.
|
||||
|
||||
Delete the given response header.
|
||||
|
||||
While header names are case insensitive, this function expects
|
||||
the name to be a lowercase binary.
|
||||
|
||||
=== has_resp_body(Req) -> boolean()
|
||||
|
||||
Return whether a response body has been set.
|
||||
|
||||
This function will return false if a response body has
|
||||
been set with a length of 0.
|
||||
|
||||
=== has_resp_header(Name, Req) -> boolean()
|
||||
|
||||
Name = binary():: Response header name.
|
||||
|
||||
Return whether the given response header has been set.
|
||||
|
||||
While header names are case insensitive, this function expects
|
||||
the name to be a lowercase binary.
|
||||
|
||||
=== reply(StatusCode, Req) -> reply(StatusCode, [], Req)
|
||||
|
||||
Alias of `cowboy_req:reply/3`.
|
||||
|
||||
=== reply(StatusCode, Headers, Req) - see below
|
||||
|
||||
Alias of `cowboy_req:reply/4`, with caveats.
|
||||
|
||||
=== reply(StatusCode, Headers, Body, Req) -> Req2
|
||||
|
||||
StatusCode = cowboy:http_status():: Response status code.
|
||||
Headers = cowboy:http_headers():: Response headers.
|
||||
Body = iodata():: Response body.
|
||||
|
||||
Send a response.
|
||||
|
||||
This function effectively sends the response status line,
|
||||
headers and body to the client, in a single send function
|
||||
call.
|
||||
|
||||
The `reply/2` and `reply/3` functions will send the body
|
||||
set previously, if any. The `reply/4` function overrides
|
||||
any body set previously and sends `Body` instead.
|
||||
|
||||
If a body function was set, and `reply/2` or `reply/3` was
|
||||
used, it will be called before returning.
|
||||
|
||||
No more data can be sent to the client after this function
|
||||
returns.
|
||||
|
||||
This function can only be called once, with the exception
|
||||
of overriding the response in the `onresponse` hook.
|
||||
|
||||
=== set_resp_body(Body, Req) -> Req2
|
||||
|
||||
Body = iodata():: Response body.
|
||||
|
||||
Set a response body.
|
||||
|
||||
This body will not be sent if `chunked_reply/{2,3}` or
|
||||
`reply/4` is used, as they override it.
|
||||
|
||||
=== set_resp_body_fun(Fun, Req) -> Req2
|
||||
|
||||
Alias of `cowboy_req:set_resp_body_fun/3`.
|
||||
|
||||
=== set_resp_body_fun(Length, Fun, Req) -> Req2
|
||||
|
||||
Fun = fun((Socket, Transport) -> ok):: Fun that will send the response body.
|
||||
Socket = inet:socket():: Socket for this connection.
|
||||
Transport = module():: Transport module for this socket.
|
||||
Length = non_neg_integer():: Length of the response body.
|
||||
|
||||
Set a fun for sending the response body.
|
||||
|
||||
If a `Length` is provided, it will be sent in the
|
||||
content-length header in the response. It is recommended
|
||||
to set the length if it can be known in advance. Otherwise,
|
||||
the transfer-encoding header will be set to identity.
|
||||
|
||||
This function will only be called if the response is sent
|
||||
using the `reply/2` or `reply/3` function.
|
||||
|
||||
The fun will receive the Ranch `Socket` and `Transport` as
|
||||
arguments. Only send and sendfile operations are supported.
|
||||
|
||||
=== set_resp_body_fun(chunked, Fun, Req) -> Req2
|
||||
|
||||
Fun = fun((ChunkFun) -> ok):: Fun that will send the response body.
|
||||
ChunkFun = fun((iodata()) -> ok):: Fun to call for every chunk to be sent.
|
||||
|
||||
Set a fun for sending the response body using chunked transfer-encoding.
|
||||
|
||||
This function will only be called if the response is sent
|
||||
using the `reply/2` or `reply/3` function.
|
||||
|
||||
The fun will receive another fun as argument. This fun is to
|
||||
be used to send chunks in a similar way to the `chunk/2` function,
|
||||
except the fun only takes one argument, the data to be sent in
|
||||
the chunk.
|
||||
|
||||
=== set_resp_cookie(Name, Value, Opts, Req) -> Req2
|
||||
|
||||
Name = iodata():: Cookie name.
|
||||
Value = iodata():: Cookie value.
|
||||
Opts = cookie_opts():: Cookie options.
|
||||
|
||||
Set a cookie in the response.
|
||||
|
||||
Cookie names are case sensitive.
|
||||
|
||||
=== set_resp_header(Name, Value, Req) -> Req2
|
||||
|
||||
Name = binary():: Response header name.
|
||||
Value = iodata():: Response header value.
|
||||
|
||||
Set a response header.
|
||||
|
||||
You should use `set_resp_cookie/4` instead of this function
|
||||
to set cookies.
|
||||
link:man:cowboy(7)[cowboy(7)]
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue