Outline

Graphics objects can be downloaded and displayed by the Windows Client from many sources. An understanding of this process can provide the opportunity for improving graphic display times.

There are three places that a graphic can be found:

Windows Client memory cache (fastest)
Windows Client disk drive
Intranet server or Internet server (slowest)

The Windows Client contains settings to control the searching and fetching of graphic objects. In the Image Properties section of the Application property sheet of the Developer Options menu choice, the user can set image extensions, and a primary and alternate graphics directory location.

The PROIV Client looks for image files by searching for the Default Bitmap Extension in the default directory named in Directory containing Images. If the image is not found, the Client searches for each Alternate Image Extension in the default directory. Next, the Client searches for the Default Bitmap Extension in the Alternate Image Search Directory Paths and then each Alternate Image Extension in each of the Alternate Image Search Directory Paths.

The Internet property sheet holds the address of a web site to use as a third location for searching (doing the complex search described for a local file but just using a single target directory), together with a directory on the local machine to act as a cache for graphics downloaded from the Internet. The Session File Caching options control the retrieval of a file that has been previously downloaded from the Internet as follows:

Always. Always downloads it from the web, do not check the timestamps.
If Newer. The timestamps of the files on the local directory and on the Internet will be compared each time the program is run to see if a new file resides on the Internet.
Not Exist. Once a file has been retrieved, no further attempt will be made to download it again.

Because of the in-depth search done to locate a file, it is highly recommended to always use a single file extension for an application. Specifying multiple extensions results in multiple directory searches, which are expensive, especially when done across the Internet.

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Topic ID: 760056