[Scribus] Creating PDF forms whose data can be saved with acrobat reader

[Craig Ringer]

Craig Ringer wrote:
> Camille Moulin wrote:
>   
>> Hi,
>>
>> Some PDFs[1] allow to save the data you fill in within Acrobat *Reader* :
>> Is it possible to generate such PDF forms with Scribus?
>>   
>>     
> No, Scribus cannot do this, but it is possible. See:
>
> http://www.adobe.com/education/designschools/tips/electronicforms.html
>
> under the heading "Enable Forms for Adobe Reader".
>
> I've been meaning to see what exactly this does to a PDF for some time. 
> I now have Acrobat, so I'll have to give it a go.
>   
OK, what it seems to do is sign the PDF - I think just a couple of parts 
of it - and add a new dictionary to the Catalog:

/Reference [ <<
/Type /SigRef
/Data 30 0 R
/TransformMethod /UR3
/TransformParams <<
/Type /TransformParams
/Annots [ /Create /Delete /Modify /Copy /Import /Export ]
/Document [ /FullSave ]
/Form [ /Add /FillIn /Delete /SubmitStandalone ]
/Signature [ /Modify ]
/V /2.2
 >>

There's more there than that, but that seems to be the key bit.

The usage rights feature used for this is documented in the PDF 
Reference 1.6 section 8.3

The signature will be to restrict who can use this feature. Quoting the 
reference: "The signature is used to validate that the permissions have 
been granted by a bonafide granting authority."  In a quick skim read I 
didn't see any definition of what such a granting authority might be, 
but the answer is probably "Adobe and major partners". A quick bit of 
searching of Adobe's site finds a lot of information about how to use 
their products (the Java interface to their libraries, the LifeCycle 
products, Acrobat, etc) to manage usage rights, but nothing on how an 
external developer might be able to do it.

In other words, enabling form saving in Adobe Reader probably costs big 
bucks.

--
Craig Ringer