Represents the form and fields associated with this
The PDF specification makes a distinction between a field (in
terms of a named value) and the visible appearance of the field on
In general one field will have one visible appearance on the
document. However it is possible for a field to have multiple or
indeed no appearances on the document.
For example a Radio Button group encapsulates one value and is
represented by one field. However each radio button has a separate
appearance on the document. So one Radio Button field is likely to
have many appearances.
For this reason fields exist within a hierarchy. Each field may
or may not have a visible appearance. Each field may or may not
have children. These children may be fields themselves and again
may have their own children.
Fields are generally referenced by fully qualified name. A full
name describes a path down through the field hierarchy - using
periods as delimiters - to a specific field object. For example the
name 'person.address.city' would reference a field with a partial
field name called 'city' which has a parent called 'address' which
has a parent at the top level called 'person'. You can resolve a
fully qualified name using the Item function.
Once a field has been obtained you can query or change its
values. If you wish to convert the fields into a permanent part of
the document you can use the Stamp method to permanently emboss