Request Module

From BaseX Documentation
Jump to navigation Jump to search

This XQuery 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[edit]

  • 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
  \_/   \_________/ \__/\_________/ \_________/
   |         |       |       |          |
 scheme   hostname  port    path      query

General Functions[edit]

request:method[edit]

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

URI Functions[edit]

request:scheme[edit]

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

request:hostname[edit]

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

request:port[edit]

Signatures 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.
Example For the example given in the introduction, this function would return 8042.

request:path[edit]

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

request:query[edit]

Signatures 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.
Example For the example given in the introduction, this function would return name=ferret.

request:uri[edit]

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

request:context-path[edit]

Signatures 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[edit]

request:address[edit]

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

request:remote-hostname[edit]

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

request:remote-address[edit]

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

request:remote-port[edit]

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

Parameter Functions[edit]

request:parameter-names[edit]

Signatures 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.
Example For the example given in the introduction, this function would return name.
Errors parameter: the request has invalid parameters.

request:parameter[edit]

Signatures request:parameter($name as xs:string) as xs:string*
request:parameter($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.
Example For the example given in the introduction, the function call request:parameter('name') would return ferret.
Errors parameter: the request has invalid parameters.

Header Functions[edit]

request:header-names[edit]

Signatures 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[edit]

Signatures request:header($name as xs:string) as xs:string?
request:header($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[edit]

request:cookie-names[edit]

Signatures 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[edit]

Signatures request:cookie($name as xs:string) as xs:string?
request:cookie($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[edit]

request:attribute-names[edit]

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

request:attribute[edit]

Signatures request:attribute($name as xs:string) as item()*
request:attribute($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.
Example
  • 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[edit]

Signatures 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 attribute: The supplied value cannot be materialized.

Errors[edit]

Code Description
attribute An attribute cannot be retrieved or stored.
parameter Request has invalid parameters.

Changelog[edit]

Version 9.3
Version 7.9
Version 7.8
Version 7.7

This module was introduced with Version 7.5.