General design principles for FileMaker WebDirect

Layouts should reflect standard best practices on the web.
Every object, style, image, and interaction on a layout means more data transferred from the Database Server to the web browser, so consider carefully what to include on a layout. Most web applications don't have hundreds of interactive objects or large, high-resolution images because web browsers cannot render them quickly enough and can be slowed by poor network connections.
Limitations that are inherent to the web also apply to FileMaker WebDirect.
The FileMaker Server or FileMaker Cloud deployment does most of the work for the FileMaker WebDirect client. For example, key presses and mouse clicks that are handled by FileMaker Pro must be sent from FileMaker WebDirect to FileMaker Server or FileMaker Cloud. The custom app's host also sets record locks, activates script triggers, fetches data, and manages layout and data caches.
Objects in HTML5 observe a true parent-child hierarchy—that is, a child object is always contained within a single parent object. For example, an image that extends across the boundary between the header and body parts of a layout can be in only one part, so the image is cropped at the boundary between the parts it spans.