Visual DataFlex

Visual DataFlex (VDF) is a 4GL, object-oriented programming language used to develop database applications. It is produced by Data Access Worldwide. VDF is sometimes called a "thin client" development tool because applications built with it do not require installation on each individual user's computer. The VDF runtime environment is instead installed on a server and users connect to it using a web browser or a "fat client" application. Once connected, users can access the application as if it were a local application installed on their own computer. This makes VDF applications ideal for use in distributed or multi-user environments. VDF is a relatively easy language to learn and use. It is based on English and uses an English-like syntax. This makes it a good choice for developers who are not familiar with more traditional programming languages such as C++ or Java. VDF applications are typically event-driven. This means that the flow of control within an application is determined by the actions of the user. For example, a button click might trigger an event that cause a particular form to be displayed. VDF applications are built around a series of objects. These objects can be visual, such as a form or a button, or non-visual, such as a database connection or a file. Each object has a set of properties that determine its behavior. For example, a button object might have a property that determines the text that is displayed on the button. A database connection object might have a property that specifies the name of the database to connect to. In addition to its basic 4GL features, VDF also includes a number of tools and libraries that make it easier to develop applications. For example, the DataFlex Studio IDE includes a number of features that streamline the development process, such as a visual form designer and a code editor. The DataFlex Foundation Class Library (DFC) is a collection of pre-built objects that can be used in DataFlex applications. These objects provide common functionality that would otherwise need to be built from scratch, such as database access and file manipulation. The DataFlex Web Application Framework (WAF) is a toolkit that simplifies the development of web-based applications. It includes a number of objects that make it easy to create forms, display data, and handle user input. Visual DataFlex is a powerful and easy-to-use programming language that is well suited for developing database applications. It is based on English and uses an event-driven, object-oriented programming model. The DataFlex Studio IDE and the DataFlex Foundation Class Library make it easier to develop applications. The DataFlex Web Application Framework simplifies the development of web-based applications.