The File Content Provider

OpenOffice.org Developer's Guide

Universal Content Providers

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• The Hierarchy Content Provider
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• The WebDAV Content Provider
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The File Content Provider (FCP), a content provider for the Universal Content Broker (UCB), provides access to the local file system by providing file content objects that represent a directory or a file in the local file system. The FCP is able to restrict access to the file system to a number of directories shown to the client under configurable aliases.

File Contents

The FCP provides content representing a directory or file in the local file system.

1. A directory contains other directories or files.
2. A file is a container for document data or content. The FCP can not determine the MediaType property of a file content.

Creation of New File Contents

A content representing directories implements the interface com.sun.star.ucb.XContentCreator. A file content object supports the command "insert". To create a new directory or file in a directory:

1. The parent directory creates a new content by calling its createNewContent() method. The content type for new folders is "application/vnd.sun.staroffice.fsys-folder". To create a new file, use the type string "application/vnd.sun.staroffice.fsys-file". A new file content object is the return value.
2. Set a title at the new file content object. The new child executes a "setPropertyValues" command that sets the property Title to a non-empty value.
3. The new file content object, not the parent, executes the command "insert". This creates the corresponding physical file or directory. For files, supply the implementation of an com.sun.star.io.XInputStream with the command's parameters that provide access to the stream data.

URL Schemes for File Contents

The file URL Scheme

Each file content has an identifier corresponding to the following scheme:

 file:///<path>

where <path> is a hierarchical path of the form

 <name1>/<name>/.../<name>.

The first part of <path> ( <name1> ) is not required to denote a physically existing directory, but may be remapped to such a directory. If this is done, the FCP refuses file access for any URL whose <name1>-part is not an element of a predefined list of alias names.

The vnd.sun.star.wfs URL Scheme

In the Sun ONE Webtop, the server-side file system is addressed with vnd.sun.star.wfs URLs. The wfs stands for Webtop File System. The file URL scheme is reserved for a potential client-side file system.

URL schemes for file contents

The vnd.sun.star.wfs URL scheme is completely hidden from the FCP, that is, the server side FCP internally works with file URLs, like any other FCP: There is a Remote Access Content Provider (RAP) between the UCB and the FCP. The RAP, among other things, can route requests to another UCP and rewrite URLs. This feature is used so that the client of the UCB works with vnd.sun.star.wfs URLs and the FCP remains unmodified and works with file URLs, with a RAP in between that maps between those two URL schemes.

Except for the different scheme name, the syntax of the vnd.sun.star.wfs URL scheme is exactly the same as the file URL scheme.

Commands and Properties

	UCB Type (returned by XContent::getContentType )	Properties	Commands	Interfaces
File	application/vnd.sun.staroffice.fsys-file	[readonly] ContentType DateCreated DateModified [readonly] IsDocument [readonly] IsFolder Size Title IsReadOnly	getCommandInfo getPropertySetInfo getPropertyValues setPropertyValues insert delete open transfer	XServiceInfo XComponent XContent XCommandProcessor XPropertiesChangeNotifier XPropertyContainer XPropertySetInfoChangeNotifier XCommandInfoChangeNotifier XChild XContentCreator
Directory	application/vnd.sun.staroffice.fsys-folder	[readonly] ContentType DateCreated DateModified [readonly] IsDocument [readonly] IsFolder Size Title IsReadOnly	getCommandInfo getPropertySetInfo getPropertyValues setPropertyValues insert delete open	XServiceInfo XComponent XContent XCommandProcessor XPropertiesChangeNotifier XPropertyContainer XPropertySetInfoChangeNotifier XCommandInfoChangeNotifier XChild

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