Custom structures client

[oroulet]

No description provided.

[oroulet]

that one works fine

[oroulet]

is that possible at all? how? @einarmo ?

[einarmo]

This is just taking the value stored in the extension object and downcasting it to the type it really is. Getting it as ErrorData would require somehow deserializing from a DynamicStructure to a specific struct. I suppose something like that could be implemented, but not trivially.

into_inner_as will only return Some if the type stored inside the extension object is the type you're calling it with. It won't do any clever conversions.

[einarmo]

If you want to actually deserialize to an ErrorData you need to create a type loader for that type, like you did on the server side. DynamicStructure is primarily intended to be used when you can't do that. For example if you are creating a generic client like UAExpert, and you want to support custom structures, you need some way to deserialize from OPC-UA binary using only runtime information.

[oroulet]

@einarmo I tried to look around in code but could not find how to deserialize to ErrorData. Any pointer?

[oroulet]

@einarmo If you know something I would really appreciate. I really feel I am overlooking something not that hard here that should should be documented

[einarmo]

Sorry. You have two real options here.

First, you can do like you do on the server and create a TypeLoader that supports ErrorData instead of using DynamicStructure.

Your other option is to do something like this:

ErrorData {
    message: dyn_structure.get_value_by_name("Message").unwrap().clone().try_cast_to().unwrap(),
    error_id: dyn_structure.get_value_by_name("ErrorId").unwrap().clone().try_cast_to().unwrap(),
    ...
}

In theory we could make a macro to implement that automatically, and maybe have a way to consume a DynamicStructure and return its values so we can drop the clone.

Part of your problem here is that you are really meant to use only one of the two methods:

• Either you know the types you need at compile time, so you make a TypeLoader to convert directly to those.
• Or you don't, so you use DynamicStructure.

You are kinda trying to do both at the same time.

[oroulet]

thanks. made decoding works now.
Next is to look at encoding
but all these hardcoded node ids is not that great. need a closer look at it later

[oroulet]

@einarmo ready now I think.

[svanharmelen]

Al lot of nitpicking, but I think good readable code is important (especially in an example, but in general as well).

[oroulet]

Al lot of nitpicking, but I think good readable code is important (especially in an example, but in general as well).

@svanharmelen not problem. I like feedback ;-)

[svanharmelen]

Noticed the changes (looks much better already), but there are still an number (4 or 5) of unresolved comments. Could you check those as well? Thanks!

[oroulet]

OK I see that maybe I should show how to do automatic serialization to rust objects too or remove code related to that here. I jsut need to find out how to do that...

[einarmo]

I made some final tidying up, and moved some of the write logic into a dedicated utility method. Small changes, mostly, but in a recent change I added a new way to define type loaders that is a lot less verbose.

[einarmo]

I'm fine with this now if you're OK with my changes @oroulet.

outdated

[oroulet]

I'm fine with this now if you're OK with my changes @oroulet.

Fine too but someone needs to approve. I cannot and maybe you cannot so @svanharmelen maybe?