How to Use the FormView Control to Edit Large Records
If a List's Detail View has large number of fields, using individual controls to edit the data can cause a significant performance hit. Using the FormView control offers a faster alternative, capable of scaling to hundreds of fields with minimal impact on load times.
By default, when you configure a List with a Detail View (so that edits can be made to the List data), the Detail View is composed using individual controls (e.g. Textbox, Textarea, Dropdown, etc). If the Detail View has a large number of fields, then composing the Detail View using individual controls will be inefficient and will result is a very large UX component that may not perform well.
An alternative approach is to use the FormView control to implement the List's Detail View. This is extremely efficient and will allow you to build UX components that edit very large forms but still perform very well.
In the video below, we show how a master-detail Form is built using a FormView control to edit the fields in the Master table and a second FormView control to edit the fields in the Detail Table. The master table has 100 fields and the detail table has 100 fields, so in total, the UX component is editing 200 fields.