Overview: Improving Application Performance

After you create an application, you can dramatically improve its performance using completion rules. The completion rules provide various methods for determining when the host has stopped sending data (either by monitoring the absence of activity from the host for a specific time interval, or by evaluating that the host has completed updating the screen).

When you specify the completion rules for an application, you should take into account the environment in which that application will be used. In a closed, reliable environment, network traffic may not be a concern. However, when connecting to a host in a different country, network considerations gain new importance. For example, in a less reliable environment, you may find program reliability an acceptable trade-off for speedy recognition of finished downloads from the host.

You can specify completion rules on a per-screen basis, or for your entire application.

Per-Screen Completion Rules

When you customize a form at design time, default completion rules are automatically generated. However, you can revise the completion rules as needed, to enhance the performance of your application. For example, using the Host Quiet completion rule, you can set a longer wait-time for a specific host screen that always takes longer to download than the other screens in your application (that is, the wait-time applies only to the currently selected screen). Using Recognition as the completion rule, the screen recognition rule is used to determine when the screen has completed. If the expected screen recognition rule never evaluates as true, the application waits the length of time you specify before it times out.

Note When you use Recognition as the completion rule, you may have to alter the screen recognition rule to make certain that it tests something that is done last.

Global Completion Rules

These rules apply to the entire application. By customizing these completion rules in concert with completion rules for individual forms, you can optimize the overall performance of your application. The Maximum Transition Time Allowed setting specifies how long an application waits for additional input from the host before determining the identity of a screen — the correct form is displayed as soon as the host screen is identified, or after waiting the specified length of time, whichever comes first. The Default completion rules enhance performance by determining when the host has completed downloading the screen. Known Destination specifies the settings used when you've set an expected destination in your application.

Static and Dynamic Forms

If your host application includes screens that do not change significantly over time, you can convert them to static forms to improve performance. Static forms are faster to present to users, and the Presentation Renderer can cache them. Identifying static screens in your host application, and changing the Type property to Static for the custom forms that were created from those screens, offers another way for you to improve your application.

Related Topics
Bullet Creating Custom Applications
Bullet Setting Completion Rules for Individual Screens
Bullet Setting Default Completion Rules for an Application
Bullet Identifying Static Screens
Bullet Adjusting How Screens are Identified, Overview
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