# &adminguide;

## Overview

The modules is an XCAP client for OpenSIPS that can be used by other modules. It fetches XCAP elements, either documents or part of them, by sending HTTP GET requests. It also offers support for conditional queries. It uses libcurl library as a client-side HTTP transfer library.

The module offers an xcap client interface with general functions that allow requesting for an specific element from an xcap server. In addition to that it also offers the service of storing and update in database the documents it receives. In this case only an initial request to the module is required - xcapGetNewDoc-which is like a request to the module to handle from that point on the referenced document so as to promise that the newest version will always be present in database.

The update method is also configurable, either through periodical queries, applicable to any kind of xcap server or with an MI command that should be sent by the server upon an update.

The module is currently used by the presence_xml module, if the 'integrated_xcap_server' parameter is not set.

## Dependencies

### &osips; Modules

The following modules must be loaded before this module:

- xcap.

### External Libraries or Applications

The following libraries or applications must be installed before running &osips; with this module loaded:

- libxml-dev.

- libcurl-dev.

## Exported Parameters

### `periodical_query`(int)

A flag to disable periodical query as an update method for the documents the module is responsible for. It could be disabled when the xcap server is capable to send the exported MI command when a change occurs or when another module in &osips; handles updates.

To disable it set this parameter to 0.

Default value is 1.

#### Set `periodical_query` parameter

    ...
    modparam("xcap_client", "periodical_query", 0)
    ...

### `query_period`(int)

Should be set if periodical query is not disabled. Represents the time interval the xcap servers should be queried for an update

To disable it set this parameter to 0.

Default value is 100.

#### Set `query_period` parameter

    ...
    modparam("xcap_client", "query_period", 50)
    ...

## Exported Functions

None to be used in configuration file.

## Exported MI Functions

### `refreshXcapDoc`

MI command that should be sent by an xcap server when a stored document changes.

Name: refreshXcapDoc

Parameters:

- document uri: the uri of the document

- xcap server port: the port of the xcap server

MI FIFO Command Format:

    ...
    :refreshXcapDoc:fifo_reply
    /xcap-root/resource-lists/users/eyebeam/buddies-resource-list.xml
    8000
    _empty_line_
    ...