| # Application development The ERP Enterprise development environment enables you to develop ERP Enterprise software. You can create package VRCs in which you can perform, for example, these actions: Set up a data model, consisting of domains and tables, for an application. To use this functionality, a development license is required. Create various types of software components, such as: Sessions Forms Reports Report scripts Multi-language data field labels Questions and messages Create, edit, and compile UI scripts, DLLs, and DALs. To use this functionality, a development license is required. Domains Domains define common information about data such as data type, length, alignment, valid ranges, display format, and capitalization rules. Table definitions A table definition defines the structure of a table. A table definition contains fields and indices. Table fields are linked to domains that define the data type and several characteristics of the fields. DAL The Data Access Layer (DAL) allows developers to describe rules about data. A DAL is linked to a table, as opposed to a session. Therefore, anytime the table is accessed, the DAL is used. In this way, different sessions can update a table and the same rules apply in the same way. In addition, integration capabilities use the DAL to insure updates will occur in the same way. Sessions A session performs an activity. Sessions are used to present data, edit data, and process data. Each session has a code. The session code is displayed in the status bar of the session window. A session consists of multiple components that work together, such as a form and an object. A session object is a compiled UI script. UI scripts The default behavior of a session is handled by the 4GL engine. If additional functionality is required or default functionality must be by-passed, this should be programmed in the session's UI script (Program script). The UI script is compiled in the session object. The object contains only the exceptions to the normal operating procedures of the system. The 4GL Engine executes the normal operating procedures of the system, and you write the exceptions. Functions Functions allow you to perform a programming task many times with different values. A function is declared in the functions section of a script, or in a library, or in a separate function script (include). Libraries A library, also called Dynamic Link Library (DLL), provides application-specific functions that can be used throughout the system, by many sessions. A library is a script that is stored in a separate component. The library is compiled independently of the program scripts that use it. Libraries are loaded at runtime by sessions that use them: when a session needs to access a library, the library is loaded and the relevant routine is executed. See also Application customization. |