Subforms can be thought of as folders containing several objects. Subforms can be used to keep order in the hierarchy, because they can be expanded and compressed.
Subform Types
Positioned
Objects of this type of subform can be laid down at their exact position at runtime, relative to the subform. The Hierarchy position of an object within a positioned subform is irrelevant for its layout position.
For example, if a text field is positioned in the top-left corner of a positioned subform, it is always positioned at the top-left corner, independent of where on a page this subform is included.
Flowed
Objects of this type of subform follow each other, depending on the space they require at runtime.
A page (design view) at the top-most subform is of type Flowed.
When to Include Subforms
Placing objects in a subform is recommended under the following conditions:
- If you want to visually group objects.
- If you want to keep objects together (protect them against page breaks).
- If you want to output the element repeatedly (as table row or table header).
- If you want to hide several elements at once.
- If you want to influence the screen reader order.
Subforms also help to rearrange several objects at a different place in the form.
Note
Be aware that nesting subforms slows down processing performance.
Preventing Page Breaks
You can make sure that certain objects appear on one page as follows:
- Select the objects.
- On the Hierarchy tab, select Wrap in subform from the context menu.
- Choose the Subform tab on the Object palette.
- Deselect the Allow Page Breaks within Content checkbox.
This option is not available on a master page or if the subform itself is included in another subform of type Positioned.
You can also prevent a page break between several subsequent subforms as follows:
On the Object palette, on the Pagination tab, choose Keep With: Previous or Keep With: Next.
The functionality of the Keep With: Previous and Keep With: Next options are as follows:
- Keep With: Previous
Keeps the subform on the same page as the previous subform, content area, or page (design view), depending on which one you choose in the Place box.
- Keep With: Next
Keeps the subform on the same page as the next subform, content area, or page (design view), depending on which one you choose in the Place box.
Hints to Create Readable Forms
Here are some hints to create readable forms:
Even though you could have no pages (design view) at all and manage everything from master pages, we strongly discourage this.
You should not nest subform B in subform A if you want subform B to be on a different master page.
If you do, the hierarchy tends to become unreadable.
Although it is possible to choose Go to Next Page or Go to Page in the After field of an ordinary subform, for the sake of clarity, you should not do so as you would force a page break.
If a page break is necessary, create a new page (design view), which is also a subform. This keeps the hierarchy clear.
- The options Keep With: Previous and Keep With: Next (to prevent a page break between two subforms) are not useful for pages (design view). You should use these options with normal subforms only.