diff options
Diffstat (limited to 'doc/src/manual/cowboy_req.match_qs.asciidoc')
| -rw-r--r-- | doc/src/manual/cowboy_req.match_qs.asciidoc | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/doc/src/manual/cowboy_req.match_qs.asciidoc b/doc/src/manual/cowboy_req.match_qs.asciidoc index e66d311..845d09a 100644 --- a/doc/src/manual/cowboy_req.match_qs.asciidoc +++ b/doc/src/manual/cowboy_req.match_qs.asciidoc @@ -15,10 +15,20 @@ match_qs(Fields :: cowboy:fields(), Req :: cowboy_req:req()) Parse the query string and match specific values against constraints. -This function allows easily retrieving expected values -from the query string, validating and converting them -in one call. In addition, the keys are converted to -atoms, making manipulation that much simpler. +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 |