Virtual File System

OpenCms comes with its own filesystem. Most data like the dynamic pages of the OpenCms Workplace as well as websites and website templates are stored in a special filesystem, the so-called Virtual File System (or VFS in short).

The VFS is completely stored in the database. It has its own set of access functions, an own, operating-system independent permission model and it knows its own set of resource types. New custom resource types can be added without modifying the core routines of opencms.

The Virtual file system cannot be normally accessed on the operating system level. There are OpenCms extensions for making it available, e.g. through an FTP service. From version 7 on, OpenCms will support WebDAV out of the box.

See also: Real File System

Resources

Files and folders in the VFS are stored in the same hierarchical manner known from other file systems. They are called resources. Each resource is associated with a resource type, the publication attribute (datereleased), the expiration attribute (dateexpired) and a set of properties.

Resource Types

A resource type in OpenCms identifies a certain type of file or folder along with the special methods required to work with these files or folders.

OpenCms includes a set of default resource types. They support the most common file types such as simple text and HTML files, images, PDF, MS Word and MS Excel, and XML files. OpenCms also knows special folder types, such as image galleries and link galleries which are handled in a special way. Image galleries are automatically made available to image selection dialogs anywhere in OpenCms.

Resource types are also responsible to extract links to other resources from a resource. It is possible to add new resource types. They are configured in /WEB-INF/config/Opencms-vfs.xml.

A resource type can be associated with a set of default properties which all resources of this type share unless a resource overrides the default value.

Resource Properties

A property is a named string literal value attached to the resource.

There are several standard properties with predefined semantics evaluated by OpenCms during work with the resource. Most prominent is the Title property which is used to display the user-defined title for a resource in the explorer. You can access property values from JSP templates via the cms:property tag.

Resource properties are an important part of OpenCms and widely used. You can define your own properties and map elements of your XML content to properties.

The list below was taken from the class org.opencms.file.CmsPropertyDefinition. It is not complete yet.

activemethod

the active method in the administration view

locale-available

the allowed set of locales

templateclass

control the Java class for body.

cache

controls the caching

ChannelId

probably deprecated because the concept of channels in version 5.x seems to have been dropped

content-conversion

content-encoding

content encoding

default-file

default file in folders

Description

resource description

enable-notification

export

boolean indicating inclusion or exclusion from static export

exportname

the resource export name, during export this name is used instead of the resource name

exportsuffix

JSP additional suffix during static export, default is "html".

folders.available

control the folders where templates or default bodies should be available

image.size

the image geometry for image resources

internal

internal use (e.g. delete)

Keywords

resource keywords

locale

locale-default

default locale of the resource

login-form

the login form

NavImage

icons to use for display of admin tools

NavInfo

used to group related tools in the admin view

NavPos

navigation position, used to determine the order of tools in the admin view

NavText

navigation text

notification-interval

relativeroot

relative root link substitution

restypes.available

name that defines the available resource types for the "new" dialog

category

sort search results in categories

search.extractionclass

define a bean for search content extraction

search.priority

to boost certain search results

secure

secure transmission of resources

stylesheet

stylesheet of files

template

control the template

template-elements

control the template elements

Title

resource title

visiblemethod

visible method in the administration view