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XFA Specification

Chapter 3, Object Models in XFA

Scripting Object Model

In the following example, the receipt template is changed to omit the

name

attribute from the detail

subforms.

Example 3.1

"name" omitted from subforms

</subform>

</subform>

…

</subform>

</template>

</xdp>

In the above example, the

Description

field for the first detail subform is referenced in the Form DOM

as:

$form.Receipt.Description[0]

while the

Description

field in the second detail subform is referenced as:

$form.Receipt.Description[1]

Similarly in the Template DOM the references would be:

$template.Receipt.Description[0]

and

$template.Receipt.Description[1]

It is as though the nameless subform was removed and its children adopted by the nameless subform's

parent. This has the side-effect of making fields into siblings that would not otherwise be siblings. For the

Total_Price

fields all three become siblings for purposes of SOM expressions even though they are

physically at different levels in the tree.

Nameless template and form objects cannot partake in the full set of functions that named objects

partake in. Rather, nameless subforms are usually inserted simply to wrap around another object in order

to lend the subform's richer capabilities to the enclosed object. For example, fields do not have

occur

properties but subforms do. As a result, it is normal to wrap a field inside a nameless subform in order to

place the field under the influence of an

occur

property. Similarly, nameless exclusion groups are mere

wrappers around sets of fields; the actual data values belong to the fields, not to the nameless exclusion

group. In the same way, all nameless template and form objects are second-class objects, of interest to the

form creator but not corresponding to data or to anything visible. The SOM expression resolver makes