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Request Functions

This module contains functions for retrieving information on an HTTP request that has triggered the query. It is mostly useful when building Web Applications.

The module is based on the EXQuery Request Module draft.

Conventions

The module will be available if the basex-api library is found in the classpath. This is the case if you use one of the complete distributions of BaseX (zip, exe, war).
All functions are assigned to the http://exquery.org/ns/request namespace, which is statically bound to the request prefix.
If any of the functions is called outside the servlet context, basex:http is raised.

The following example illustrated what components a URI may consist of (the example is derived from RFC 3986):

  foo://example.com:8042/over/there?name=ferret&code=7
  \_/   \_________/ \__/\_________/ \________________/
   |         |       |       |              |
 scheme   hostname  port    path          query

General Functions

`request:method`

Signature	request:method() as xs:string
Summary	Returns the Method of the HTTP request.

URI Functions

`request:scheme`

Signature	request:scheme() as xs:string
Summary	Returns the Scheme component of the URI of an HTTP request.
Examples	For the example given in the introduction, this function would return `foo`.

`request:hostname`

Signature	request:hostname() as xs:string
Summary	Returns the Hostname component of the URI of an HTTP request.
Examples	For the example given in the introduction, this function would return `example.com`.

`request:port`

Signature	request:port() as xs:integer
Summary	Returns the Port component of the URI of an HTTP request, or a default port if it has not been explicitly specified in the URI.
Examples	For the example given in the introduction, this function would return `8042`.

`request:path`

Signature	request:path() as xs:string
Summary	Returns the Path component of the URI of an HTTP request.
Examples	For the example given in the introduction, this function would return `/over/there`.

`request:query`

Signature	request:query() as xs:string?
Summary	Returns the Query component of the URI of an HTTP request. If no query component exists, an empty sequence is returned.
Examples	For the example given in the introduction, this function would return `name=ferret&code=7`.

`request:uri`

Signature	request:uri() as xs:anyURI
Summary	Returns the complete URI of an HTTP request as it has been specified by the client.
Examples	For the example given in the introduction, this method would return `foo://example.com:8042/over/there?name=ferret&code=7`.

`request:context-path`

Signature	request:context-path() as xs:string
Summary	Returns the context of the request. For servlets in the default (root) context, this method returns an empty string.

Connection Functions

`request:address`

Signature	request:address() as xs:string
Summary	Returns the IP address of the server.

`request:remote-hostname`

Signature	request:remote-hostname() as xs:string
Summary	Returns the fully qualified hostname of the client that sent the request.

`request:remote-address`

Signature	request:remote-address() as xs:string
Summary	Returns the IP address of the client that sent the request.

`request:remote-port`

Signature	request:remote-port() as xs:string
Summary	Returns the TCP port of the client socket that triggered the request.

Parameter Functions

`request:parameter-names`

Signature

request:parameter-names() as xs:string*

Summary Returns the names of all query and form field parameters available from the HTTP request. With RESTXQ, this function can be used to access parameters that have not been statically bound by %rest:query-param.

Errors

parameter Request has invalid parameters.

Examples For the example given in the introduction, this function would return name.

`request:parameter`

Signature

request:parameter(
  $name     as xs:string,
  $default  as xs:string  := ()
) as xs:string*

Summary Returns the value of the named query or form field parameter in an HTTP request. If the parameter does not exist, an empty sequence or the optionally specified default value is returned instead. If both query and form field parameters with the same name exist, the form field values will be attached to the query values.

Errors

parameter Request has invalid parameters.

Examples For the example given in the introduction, the function call request:parameter('code') would return 7.

Header Functions

`request:header-names`

Signature	request:header-names() as xs:string*
Summary	Returns the names of all headers available from the HTTP request. If RESTXQ is used, this function can be used to access headers that have not been statically bound by `%rest:header-param`.

`request:header`

Signature	request:header( $name as xs:string, $default as xs:string := () ) as xs:string?
Summary	Returns the value of the named header in an HTTP request. If the header does not exist, an empty sequence or the optionally specified default value is returned instead.

Cookie Functions

`request:cookie-names`

Signature	request:cookie-names() as xs:string*
Summary	Returns the names of all cookies in the HTTP headers available from the HTTP request. If RESTXQ is used, this function can be used to access cookies that have not been statically bound by `%rest:cookie-param`.

`request:cookie`

Signature	request:cookie( $name as xs:string, $default as xs:string := () ) as xs:string?
Summary	Returns the value of the named Cookie in an HTTP request. If there is no such cookie, an empty sequence or the optionally specified default value is returned instead.

Attribute Functions

`request:attribute-names`

Signature	request:attribute-names() as xs:string*
Summary	Returns the names of all HTTP request attributes.

`request:attribute`

Signature

Signature	request:attribute( $name as xs:string, $default as item()* := () ) as item()*
Summary	Returns the value of an attribute of the HTTP request. If the attribute does not exist, an empty sequence or the optionally specified default value is returned instead.
Examples	`request:attribute("javax.servlet.error.request_uri")` Returns the original URI of a caught error. `request:attribute("javax.servlet.error.message")` Returns the error message of a caught error.

request:attribute(
  $name     as xs:string,
  $default  as item()*    := ()
) as item()*

Summary Returns the value of an attribute of the HTTP request. If the attribute does not exist, an empty sequence or the optionally specified default value is returned instead.

Examples

request:attribute("javax.servlet.error.request_uri")

Returns the original URI of a caught error.

request:attribute("javax.servlet.error.message")

Returns the error message of a caught error.

`request:set-attribute`

Signature	request:set-attribute( $name as xs:string, $value as item()* ) as empty-sequence()
Summary	Binds the specified `$value` to the request attribute with the specified `$name`.

Errors

Code	Description
`parameter`	Request has invalid parameters.

Changelog

Version 9.3

Added: request:attribute-names, request:set-attribute
Updated: request:attribute: return type generalized, default argument added

Version 7.9

Updated: The returned values of request:parameter-names, request:parameter now also include form field parameters.

Version 7.8

Added: request:context-path

Version 7.7

Added: request:attribute

Version 7.5

Added: New module added.

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