Acrobat plug-in loading order

[juhyunk58976314]

Hi,

Does anyone know where I can find some information about the order in which plug_in api files get loaded when opening Acrobat in Windows?

In most cases, the loading order should not matter, but I am in a situation that it matters. From my own tests, I figured out that the file & folder names under plug_ins count in the alphabetical order. B.api loads before C.api but after A\A.api. This assumption has worked for a while. Sometimes I resolved issues by renaming D.api into B.api to make it load prior to C.api.

However, I faced with a counterexample today. In this situation, C.api always loads first no matter what I do with B.api, and I still have no idea how C.api can take the precedence. Perhaps is it related with plug_in extension name? And I have no control over C.api at this moment other than renaming it.

Any information will be appreciated. Thank you.

- eellor

[Karl Heinz Kremer]

The order in which plug-ins are loaded, should not matter. That's why plug-ins use the different handshake events to first export HFT functions that may be used by other plug-ins, and then in a second event, these get imported. If you have a dependency on the order, you may want to re-think your plug-in design.

I did some research 10 or 15 years ago about the order in which plug-ins were loaded, and if I remember correctly, it depended on the operating system and the filesystem used.

[juhyunk58976314]

Thank you Karl for the quick answer.

I know how HTF works and the loading order should not matter in terms of dependency, but my problem is something different. The plug-ins don't depend on each other, but still the order of loading matters.

It is a situation that 2 plug-ins are competing for different .NET CLR versions. Both create AppDomains, but one in .NET CLR 2.0 and the other in 4.0. If 2.0 comes first, it the other plug-in fails. If 4.0 comes first, both works, thanks to .NET 4.0's side-by-side technique.

So your research says that the order is undefined from Acrobat's side. And I just found a supporting note like this from SDK API document:

**

ASFileSysFirstFolderItem

Note:The order in which items are enumerated is implementation-dependent. Of particular importance is the fact that items will probably not be iterated in alphabetic order.

**

I don't know if Acrobat uses this API to load its plug-ins, but guess there are chances. Then, your observation must be correct, it may be undefined. This is what I didn't want to hear, though. I'll wait for other opinions, with hope. Thank you.

- eellor

[lrosenth]

The order is not documented in case we choose to change it (as we have in various versions of the application for various reasons).

So if you require a specific order you may be in trouble.