Missing information in Actions file specification

Question

I wrote some code that parses the Photoshop Actions palette file. I used the Photoshop CS2 File Formats Specification PDF (dated June 2005) to understand its format. However, the following OSType keys of the "Reference Structure" type are not documented:
'Idnt' (Identifier)
'indx' (Index)
'name' (Name)
They are mentioned in Table 3.4, page 62 of the PDF.
This seems to be a lack in the document since all the other many elements are explained in great detail. Can anybody provide details of these missing fields? What I need is information on their size (length in bytes) and/or the description of their physical structure in the Actions file. I searched this forum for more info to no avail.
Thanks in advance,
Ettore Pasquini

Answer 1

Name, Index, and Identifier (along with all other reference types) have a value
structured like
'unicode string' - 'desired classID' - 'actual value'
The initial unicode string is not meaningful, as near as I can tell. It does get
populated by actions on very rare occasions, but does not appear to be used
anywhere. I always write it out as an empty unicode string and the action
behaves the same.
You've accurately deduced the classID part.
I should have mentioned all of this in the previous email.
For Name, the value is a Unicode string.
For Index, the value is a simple 4 byte word.
For Identifier, values a simple 4 byte key-classID.
I have a test script that generates writes/read/writes and verifies descriptors
in Javascript. This includes the code for ieee754 floats, Alias (pth or alis),
and raw (tdta) data types. I haven't tested my Alias code out on an action
created on a Mac, though. The only one I haven't figured out at all is
ObjectArray (ObAr). I can't create it with the JS API nor have I found it in my
largish collection of Action files.
If you'd like, I can send you the script(s) that I use for my implementation and
testing. You might find it of some use in your work. I also have a partial perl
implementation if that's more your speed.
Ettore Pasquini wrote:
> thanks for the reply xbytor.
>
> 'indx' - a 4 byte word/integer
> 'name' - a unicode string
>
>
>
>
> According to my tests those mappings don't work. I have some actions files with those elements and the file is not correctly parsed if I adopt the formats above. However I found out the following seems to work:
>
> 'indx' :
> Variable - Unicode string;
> Variable - 4 bytes of length followed by ASCII string;
No. This is a classID.
> 4 - 4 additional bytes of unknown meaning.
This is the actual value of the index. I see it used a lot when indexing a
document's layers.
>
> 'name' :
> Variable - Unicode string;
> Variable - classID: 4 bytes (length), followed either by string or (if length is zero) 4-byte classID;
> Variable - Unicode string.
Exactly right.
>
> This is based entirely on empirical observations and of course it could be wrong. But so far these formats seems to satisfy the data in all my actions files.
>
> For the 'Idnt' element I haven't the slightest idea of what it could be, since I never saw one in an Actions Palette file.
I can create Idnt's but I don't recall having seen them either.
> Can anyone from Adobe please provide this information and verify the above hypotheses? It would be extremely helpful. Thanks!
>
> -Ettore
Let me know if you want the scripts.
for photoshop scripting solutions of all sorts
contact: [email protected]