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QUESTION: What is a PDF form?
ANSWER: A PDF form is a
PDF file that
a computer user can interact with.
A PDF form contains boxes where a
user can type text, lists from which a user
can choose particular items,
buttons that a user
can click on, etc.
Creating PDF forms
There are various software applications that allow you to
use a point-and-click interface to create PDF forms.
Most people probably use a commercial
version of the Adobe Acrobat
software to create them. (When we say "a commercial version,"
we mean a version of Adobe Acrobat that costs a few hundred dollars.
The free Adobe Reader software cannot be used to create PDF forms.)
Another Adobe product that can be used to create PDF forms is
Adobe LiveCycle Designer (formerly known as "Adobe Designer" — more
about this below).
In addition to the applications mentioned above,
there are various applications made by companies other than Adobe
that allow you to create forms.
Using PDF forms
The mechanisms that allow a user to
interact with a PDF form
are contained in some "PDF-viewer" applications.
The most widely used PDF-viewer applications are the
Adobe Acrobat software
and the Adobe Reader software.
PDF forms are sometimes used to collect
information from users via the Internet
or via an Intranet. In these cases,
a Web server
sends PDF forms out over the Internet
or Intranet
to a Web browser on a user's computer,
and the PDF forms are displayed
in the Web-browser window
by PDF-viewer software
that is running on that user's
computer. The PDF-viewer software (for example, the Adobe Acrobat
software or Adobe Reader software)
actually
runs inside the Web browser, renders
the PDF form inside the Web-browser window,
and manages the user's interaction with the
text boxes, lists, and buttons, etc. that
are on the PDF form.
Most PDF forms contain a button that a
user is supposed to click when he has
finished filling out the form. In the
typical case, the data that was entered by
the user and the selections that were made
by the user are sent over the Internet or
Intranet to a Web server when the user
clicks this button. Software on the Web
server then takes control and uses
the data as required. For example,
the software on the Web server might
store the data in a database for later use.
Or, the software on the Web server
might utilize the data to generate
a document of some kind — often this
is done by populating a PDF form
dynamically (that is, programmatically).
Besides allowing a human user to interact with a PDF form,
there are other ways to put information into the fields in a
PDF form. If you'd like to learn about programmer's toolkits/libraries that
can facilitate development of a system that populates PDF forms
dynamically, click here.
Note that
it is also possible to make use of
PDF forms without involving a Web server.
For example, a user can fill out a PDF form,
save it, and then e-mail it somewhere.
IMPORTANT NOTE: Prior to the release of Adobe Acrobat 8,
it wasn't possible to use the free Adobe Reader software to
save a filled-in PDF form. However, Adobe Acrobat 8 allows you
to create PDF forms that can be saved in the free Adobe Reader
software.
Two kinds of PDF forms
There are two different kinds of PDF forms:
- The "old kind." Technically, this kind of form is known
as an "AcroForm."
- The "new kind." Technically, this kind of form is known as
an "XFA-based form."
What’s the difference between the two?
AcroForm (old kind)
An AcroForm can be created with
Adobe Acrobat 4.x, 5.x, 6.x, 7.x, or 8.x; and a user can interact with
an AcroForm by using Adobe Acrobat 4.x, 5.x, 6.x, 7.x, or 8.x or by using
the free "Reader" application for one of those
Adobe Acrobat versions. In addition, there are quite a few developer’s
tools/libraries that allow a
programmer to create a system that populates (fills) AcroForms automatically
(see SolutionFinder_PDFStampingMergingFormFilling.htm).
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XFA-based form (new kind)
XFA-based forms were introduced by
Adobe a few years ago. XFA is a format that is based on technology
developed by a company named "Accellio," which was acquired by
Adobe several years ago.
"XFA" stands for "XML Forms Architecture"; and
XFA-based forms are so named because the appearance and behavior of
an XFA-based form is dictated by an XML data structure inside the PDF file.
Prior to the release of Adobe Acrobat 7, you had to purchase the "Adobe Designer"
application to create an XFA-based form. However, when Adobe Systems
released Adobe Acrobat 7, they bundled the
Adobe Designer application (now called "Adobe LiveCycle Designer 7.0")
with Adobe Acrobat 7; and they also added to Adobe Acrobat 7
some menu controls that let you initiate the creation of an XFA-based form
from within Adobe Acrobat 7.
Note that XFA-based forms can’t be guaranteed to work properly with
versions of Adobe Acrobat/Adobe Reader older than Version 7.
Also, most of the non-Adobe developer’s tools and libraries that allow a
programmer to populate PDF forms automatically DO NOT work with XFA-based forms.
Are you confused yet? There’s more. . . !
There are actually two different ways to create a PDF form if you’re working
within Adobe Acrobat 7, and depending upon which way you do it,
you’ll either get an AcroForm or an XFA-based form.* Specifically:
- If you click Tools > Advanced Editing and then use the Button Tool,
Check Box Tool, Combo Box Tool, etc. on the drop-down menu,
you’ll be creating an AcroForm.
- But if you click Advanced > Forms > Create New Form,
Adobe LiveCycle Designer 7.0 will be launched, and you’ll be creating
an XFA-based form.
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Why is all of this important? Because if you’re developing a
workflow or a document-creation system that is based on PDF forms,
you’ll want to make sure that everything is going to work properly.
For example: don’t create XFA-based forms and expect to use
non-Adobe software to populate them dynamically, because you
probably are not going to find a developer’s tool/library that can handle this.
If you are a developer that would like to gain a deeper understanding of
Acrobat Forms vs. XFA-based forms, we recommend that you go
to www.pdfzone.com and join
the PDF-Forms discussion list.
PDF forms vs. HTML forms
PDF forms can
function very much like the HTML forms
that are typically employed these days to collect
data from users on the Internet or within
an Intranet. If you are creating a
software system that will collect data from
users on the Internet or on an Intranet,
you might want to consider using PDF forms
instead of using the more-conventional
HTML forms. Click here
to see some guidelines that explain
when to use HTML forms and when to use PDF forms.
How to get more information about PDF forms
It is easy to obtain free information about
PDF forms. Here is some information about
resources that you can use to get started:
If you own the full version
of the Adobe Acrobat software, read the
information about PDF forms in the on-line
Adobe Acrobat documentation.
Visit the
Planet PDF "Forums" area,
register as a guest, and browse through the
on-line "Forms & FDF" discussions.
Visit the
PDFzone "Discussions" area
and peruse the archives for the PDF-forms Discussion.
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