RealWeb

Introduction

RealWeb provides the Web developer with access to data held in a Reality database, by making it possible to call a DataBasic subroutine directly from a Web browser by simply specifying a URL Uniform Resource Locator - a web address. . Subroutines that will be called from RealWeb must be specially written using the supplied DataBasic API Application Programming Interface - a set of functions that you can use in your programs to work with a component.  - this allows the programmer to fetch arguments passed to RealWeb, and to construct an web page that is returned for display in the browser. Alternatively, complete web pages and images can be retrieved from a database.

By using an HTML form, information entered by the user can be included in the URL and passed as arguments to a Reality subroutine. These arguments can be used in various ways - for example, to construct queries or to update the database.

Features

RealWeb consists of a set of Java Servlets A server-side Java program that services HTTP requests and returns HTTP responses.  that run on a Web server and a DataBasic API Application Programming Interface - a set of functions that you can use in your programs to work with a component.  for constructing the web pages that are returned to the browser. Connection between the Web server and Reality is by means of Remote BASIC A mechanism by which DataBasic subroutines can be called from a remote system. .

Servlets are provided to:

• Configure RealWeb connections.
• Call a DataBasic subroutine that constructs a web page.
• Return a complete item from the Reality database.

RealWeb Connections

RealWeb supports one-shot and persistent connections:

• In one-shot connection mode, a pool of Remote Basic servers can be held open to handle incoming requests efficiently.
• Persistent connection mode will guarantee that a browser that created a connection will get the same connection when accessing a subsequent page. This enables item locks, transaction boundaries and application context to be maintained across several Web pages. Optionally, when in persistent mode, the user can be prompted for a Reality user-id and password before starting a new connection.

The RealWeb API

The RealWeb API Application Programming Interface - a set of functions that you can use in your programs to work with a component. is a toolkit that the DataBasic programmer can use to interface to the Web browser - that is, to access arguments passed as part of the URL Uniform Resource Locator - a web address. and to construct the HTML page that will be returned to the browser. Routines are provided to do the following:

• Fetch the values of arguments passed to RealWeb by the browser.
• Start and end an HTML page.
• Format text in various ways - for example, as a heading; left, centre or right aligned; fixed-pitch; in a particular font size and colour.
• Insert a horizontal rule.
• Create a hyperlink.
• Create an HTML form containing push buttons, text boxes and drop down lists.
• Create a definition list.
• Fetch and manipulate cookies A cookie is a small amount of named data stored by the web browser and associated with a particular page or web site. Cookies serve to give the web browser a memory, so that it can recall user preferences or other state variables when the user leaves a page and subsequently returns, or can pass data between pages.  .

Using RealWeb

The following sections give the information you will need to install and use RealWeb:

• Installing RealWeb.
• Configuring RealWeb.
• Writing a RealWeb Subroutine.
• Calling a RealWeb Subroutine.

Related documentation covering Reality, DataBasic and HTML is listed in Related Documents.