Kbase 21648: New 4GL Features in V9
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
4/30/2002 |
|
Status: Unverified
GOAL:
Progress 4GL New features in V9
FACT(s) (Environment):
Progress 9.x
FIX:
The 4GL language has evolved and matured with each release of Progress and represents the confluence of several technologies into a single programming environment. With Progress Version 9, Progress continues to make significant enhancements to the 4GL.
New GUI Features
Three new database objects allows the creation of Dynamic Queries:
QUERY Object:
The QUERY object is one-to-one with a Progress query. If the QUERY object is associated with an existing static query, it allows the manipulation of the static query's predicate and attributes at runtime. The QUERY object can also be used to dynamically create a query. If you create a dynamic query, the QUERY object creates an empty query that will get its predicate and buffers assigned to it using methods and attributes at runtime.
BUFFER Object:
The BUFFER object is one-to-one with a Progress buffer. This object can be associated with a normal compiler-specified Progress buffer. In this case, the BUFFER object allows you to manipulate it and its fields. It can also be used to create a Progress buffer for a table specified at runtime. The object allows updating, creating, and deleting using methods. If the BUFFER is dynamic, records can be read into the BUFFER object using a dynamic QUERY object and the SET-BUFFERS method shown earlier.
BUFFER-FIELD Object:
The BUFFER-FIELD object represents a field in a BUFFER object. When a BUFFER object is used to reference its fields via the NUM-FIELDS attribute or the BUFFER-FIELD() method, a new BUFFER-FIELD object is created for each field in the BUFFER. This object is needed to support the BUFFER object, since it gives access to the BUFFER's fields. The BUFFER-VALUE allows extraction and update of the value of a BUFFER field.
Browse Control Column Attributes and Methods:
These browser enhancements provide greater flexibility in development and deployment. New attributes include VISIBLE which allows columns to be hidden and ALLOW-COLUMN-SEARCHING which supports column searching on read-only browsers.
New methods delivered in Version 9 include ADD-LIKE-COLUMNS, ADD-COLUMNS-FROM and ADD-CALC-COLUMNS.
These methods allow columns to be dynamically added to a browser at runtime.
New Image Formats:
New file formats for images added in Version 9 allow greater ease of application integration. In addition to Windows Bitmap and Icon file formats there many new formats, three of which are: GIF, TIFF and JPEG. Previously when simultaneously developing in WebSpeed® and Progress, developers had to use different image types. Now one image type can be used in an application developed in both environments. In addition, DEFINE IMAGE has three new options to give greater control over these images. These options are RETAIN-SHAPE, STRETCH-TO-FIT and TRANSPARENT.