This section provides an overview of Web services, and general information on the SOAP protocol. In addition, several basic implementation architectures are described.
This section contains these topics:
Web services reside as a layer on top of existing software systems such as application servers, .NET servers, and the Content Server. Web services can be used as a bridge to dissimilar operating systems or programming languages.
Web services are adapted to the Internet as the model for communication and rely on the HyperText Transfer Protocol (HTTP) as the default network protocol. Thus, using Web services, you can build applications using a combination of components.
Oracle WebLogic Server provides SOAP capabilities, and Content Server supports several SOAP requests through Oracle WebLogic Server. For more information, see Chapter 7, "Using Oracle UCM Web Services".
The core enabling technologies for Web services are XML, WSDL, SOAP, and UDDL:
��XML: Data: The eXtensible Markup Language (XML) is a bundle of specifications that provides the foundation of all Web services technologies. Using the XML structure and syntax as the foundation allows for the exchange of data between differing programming languages, middleware, and database management systems.
��SOAP: Communication: The Simple Object Access Protocol (SOAP) Content Servers communication for Web services interfaces to communicate to each other over a network. SOAP is an XML-based communication protocol used to access Web services. Web services receive requests and return responses using SOAP packets encapsulated within an XML document.
��UDDI: Registry: The Universal Description Discovery and Integration (UDDI) service provides registry and repository services for storing and retrieving Web services interfaces. UDDI is a public or private XML-based directory for registration and lookup of Web services.
Public or private UDDI sources are not published. However this does not prevent users from integrating Content Server with other applications using Web services.
The XML, WSDL, SOAP, and UDDI technologies work together as layers on the Web services protocol stack. The Web services protocol stack consists of these layers:
The service transport layer between applications (HTTP). While several protocols are available as a transport layer (for example, HTTP, SMTP, FTP, BEEP), the HTTP protocol is most commonly used.
The messaging layer that provides a common communication method (XML and SOAP).
The service description layer that describes the public interface to a specific Web service (WSDL).
The service discovery layer that provides registry and repository services for storing and retrieving Web services interfaces (UDDI).
The Folders/WebDAV component is available as an extra component for download from the support site. You can use the Folders component to set up an interface to the Content Server in the form of virtual folders that enables you to create a multilevel folder structure and also use the WebDAV component to remotely author and manage your content using clients that support the WebDAV protocol.
The Folders component provides a hierarchical folder interface to content in Content Server. The component is required for WebDAV functionality, and the WebDAV Client product.
The WebDAV component enables WebDAV (Web-Based Distributed Authoring and Versioning) functionality to remotely author and manage your content using clients that support the WebDAV protocol. For example, you can use Microsoft Windows Explorer to check in, check out, and modify content in the repository rather than using a Web browser interface.
The option to install the WebDAV component is provided during the Folders/WebDAV installation process. See the Oracle Fusion Middleware Application Administrator's Guide for Content Server for additional information.
The Folders component sets up an interface to the Content Server in the form of virtual folders (also called hierarchical folders). Virtual folders enable you to create a multilevel folder structure.
Virtual folders provide two main benefits:
Users can find content by drilling down through a familiar folder-type interface.
Users can apply default metadata to content items by checking them in through a particular folder.
The following structure is used for the Folders component:
Each Content Server instance has a common set of virtual folders. Any change to the folders is applied systemwide.
There is one default system-level folder, called Content Server Folders. If you are using a custom folders interface, folders for these products may also appear at the system level of the Folders hierarchy.
The system administrator can change the name of a system-level folder, but cannot delete it or add a custom system-level folder except through changes to the database. (Deleting a system-level folder disables it, but does not remove it from the system.)
Each folder in the hierarchy contains content items that have the same numeric Folder value, which is assigned automatically upon creation of the folder. Changing the value of the Folder field for a content item places it in a different folder.
The number of folders and number of files in each folder can be limited by the system administrator so that virtual folder functions do not affect system performance.
WebDAV (Web-Based Distributed Authoring and Versioning) provides a way to remotely author and manage your content using clients that support the WebDAV protocol. For example, you can use Microsoft Windows Explorer to check in, check out, and modify content in the repository rather than using a Web browser interface.
WebDAV is an extension to the HTTP/1.1 protocol that allows clients to perform remote Web content authoring operations. The WebDAV protocol is specified by RFC 2518.0.
See the WebDAV Resources Page at http://www.webdav.org for more information
WebDAV provides support for the following authoring and versioning functions:
Version management
Locking for overwrite protection
Web page properties
Collections of Web resources
Name space management (copy/move pages on a Web server)
Access control
When WebDAV is used with a content management system such as Content Server, the WebDAV client serves as an alternate user interface to the native files in the content repository. The same versioning and security controls apply, whether an author uses the Content Server Web browser interface or a WebDAV client.
In Content Server, the WebDAV interface is based on the hierarchical Folders interface. See "Virtual Folders" for additional information.
A WebDAV client is an application that can send requests and receive responses using a WebDAV protocol (for example, Microsoft Windows Explorer, Word, Excel, and PowerPoint). Check the current WebDAV Client documentation for specific versions supported. This is not the same as the Content Server WebDAV Client, which is a product that enhances the WebDAV interface to the Content Server.
You can use WebDAV virtual folders in Windows Explorer to manage files that were created in a non-WebDAV client, but you cannot use the native application to check content in and out of the Content Server repository.
The Desktop software package also includes a WebDAV Client component and a Check Out and Open component.
A WebDAV server is a server that can receive requests and send responses using WebDAV protocol and can provide authoring and versioning capabilities. Because WebDAV requests are sent over HTTP protocol, a WebDAV server typically is built as an add-on component to a standard Web server.
In Content Server, the WebDAV server is used only as an interpreter between clients and the Content Server.
WebDAV is implemented in the Content Server by the WebDAV component. The architecture of a WebDAV request follows these steps:
The WebDAV client makes a request to the Content Server.
The message is processed by the Web Server (through a DLL in IIS).
On the Content Server, the WebDAV component performs these functions:
Recognizes the client request as WebDAV.
Maps the client request to the appropriate WebDAV service call on the Content Server.
Converts the client request from a WebDAV request to the appropriate Content Server request.
Connects to the core Content Server and executes the Content Server request.
The WebDAV component converts the Content Server response into a WebDAV response and returns it to the WebDAV client.