From d7580dbfdbdcf3ecf085479b6550284a47745138 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Lo=C3=AFc=20Hoguin?= Date: Fri, 28 Apr 2023 13:34:22 +0200 Subject: Cowboy 2.10.0 --- .../2.10/manual/cowboy_req.match_qs/index.html | 218 +++++++++++++++++++++ 1 file changed, 218 insertions(+) create mode 100644 docs/en/cowboy/2.10/manual/cowboy_req.match_qs/index.html (limited to 'docs/en/cowboy/2.10/manual/cowboy_req.match_qs') diff --git a/docs/en/cowboy/2.10/manual/cowboy_req.match_qs/index.html b/docs/en/cowboy/2.10/manual/cowboy_req.match_qs/index.html new file mode 100644 index 00000000..b45ee305 --- /dev/null +++ b/docs/en/cowboy/2.10/manual/cowboy_req.match_qs/index.html @@ -0,0 +1,218 @@ + + + + + + + + + + Nine Nines: cowboy_req:match_qs(3) + + + + + + + + + + + + + +
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99s

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cowboy_req:match_qs(3)

+ +

Name

+

cowboy_req:match_qs - Match the query string against constraints

+

Description

+
+
match_qs(Fields :: cowboy:fields(), Req :: cowboy_req:req())
+    -> #{atom() => any()}
+
+

Parse the query string and match specific values against constraints.

+

Cowboy will only return the query string values specified in the fields list, and ignore all others. Fields can be either the key requested; the key along with a list of constraints; or the key, a list of constraints and a default value in case the key is missing.

+

This function will crash if the key is missing and no default value is provided. This function will also crash if a constraint fails.

+

The key must be provided as an atom. The key of the returned map will be that atom. The value may be converted through the use of constraints, making this function able to extract, validate and convert values all in one step.

+

Arguments

+
Fields
+

Fields to retrieve from the query string.

+

See cowboy(3) for a complete description.

+
+
Req
+

The Req object.

+
+
+

Return value

+

Desired values are returned as a map. The key is the atom that was given in the list of fields, and the value is the optionally converted value after applying constraints.

+

The map contains the same keys that were given in the fields.

+

An exception is triggered when the match fails.

+

Changelog

+
  • 2.0: Function introduced. +
    • +
+

Examples

+
Match fields
+
+
%% ID and Lang are binaries.
+#{id := ID, lang := Lang}
+    = cowboy_req:match_qs([id, lang], Req).
+
+
Match fields and apply constraints
+
+
%% ID is an integer and Lang a non-empty binary.
+#{id := ID, lang := Lang}
+    = cowboy_req:match_qs([{id, int}, {lang, nonempty}], Req).
+
+
Match fields with default values
+
+
#{lang := Lang}
+    = cowboy_req:match_qs([{lang, [], <<"en-US">>}], Req).
+
+

See also

+

cowboy_req(3), cowboy_req:qs(3), cowboy_req:parse_qs(3)

+ + + + + + +
+ +
+ + +

+ Cowboy + 2.10 + Function Reference + +

+ + + +

Navigation

+ +

Version select

+ + +

Like my work? Donate!

+

Donate to Loïc Hoguin because his work on Cowboy, Ranch, Gun and Erlang.mk is fantastic:

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Recurring payment options are also available via GitHub Sponsors. These funds are used to cover the recurring expenses like food, dedicated servers or domain names.

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