In a form design that has a fixed layout, you typically use only one subform (the default subform on the page), which LiveCycle Designer ES sets to position content by default. When LiveCycle Designer ES positions the content in a subform, none of the objects within the subform move from their anchored positions, regardless of the characteristics and quantity of data.However, if you want sections of the form to expand to accommodate data, you generally use multiple subforms: the default subform on the page, which you set to flow content, along with additional subforms that you can set to repeat for each data item, expand to fit, or both. When you reset a subform to flow content, the objects within the subform, including other subforms, move to accommodate the data merged into the repeating and expanding subforms.With LiveCycle Designer ES, you can bind the objects in the form to the data elements in a data file, and you can configure the text field and subform objects in the form to appear, repeat, or expand, depending on the characteristics and quantity of data merged with the object. Because the objects in the form are bound to the source data, the layout of the form is data-driven.When authoring a form design that contains sections that expand and shrink to accommodate data, it is important to understand which subforms will only appear once in the form, such as an address block, and the subforms that will repeat according to the amount of data, such as a detail line. For those subforms that will repeat, you include only one instance of the subform and its components in the form design. Consequently, what you see at design time is not what users see when the form is rendered.For example, the following illustrations of the non-interactive Purchase Order sample show the form design before it is merged with data and the resulting form that is presented to a user after the form design is merged with data. Notice how the detail line (detail subform) repeats four times to accommodate the list of parts (available data).
