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XFA Specification

Chapter 8, Dynamic Forms

Data Binding for Dynamic Forms

264

The template for the dynamic purchase order on

page 261,

omitting decorative elements, is as follows:

</subform>

</subform>

</template>

The

Detail

subform has no maximum occurrences and defaults to a minimum of one. This is typical for a

subform corresponding to one in a list of records. The

Delivery

subform has no minimum occurrences

and defaults to a maximum of one. This is typical for a record which is optional.

The DOM relationships for this example are not shown here because the drawing would not fit in the

space available.

The Occur Element

Each subform and subform set object has an

occur

property which has three sub-properties,

min, max,

and

initial.

It governs how many iterations of the subform or subform set are required and how many are

permitted.

In a template the occur property is expressed as an

occur

element. It can be the child of a subform or

subform set. When the

occur

element is missing, all of the sub-properties default to 1. If the element is

present but any of its attributes is missing, the sub-property associated with that attribute defaults to 1.

The initial property

The initial property determines how many copies of the subform or subform set are included in the Form

DOM as siblings during an empty merge. The value of this property must be a non-negative integer. For

example, consider the following template fragment: