inject environment for verbs

[plata]

It is currently not possible to get resources for a verb (e.g for the registry, see #511).

Decide if it makes sense to inject environment to solve this.

The basic issue is the following: A script/verb is not aware of its location in the repository.

[plata]

@madoar let's continue here.

[plata]

1. Injecting when a script is executed: This is already done for TYPE_ID etc. I don't see how it could be used for a verb.
2. Injecting in include call: Could be possible but how should the variables look like, i.e. how to avoid that several includes overwrite each other?

[madoar]

I believe the question is, how do we define a verb.
Is it an independent environment, or is it a part of a script and should therefore also be able to access variables of the script environment.

[plata]

It is part of the script.

[madoar]

1. Aren't the verbs loaded in the same nashorn engine as the script itself?
   If this is the case they should share the same global variables.
2. The IncludeInjector currently prevents multiple includes from overwriting each other:

           if (includedScripts.add(Arrays.asList(arguments))) {
               nashornEngine.eval("//# sourceURL=" + Arrays.asList(arguments).toString() + "\n" + script,
                       this::throwException);
           }

   includedScripts.add(Arrays.asList(arguments)) returns false, when the script, defined by the arguments, is already included.

[plata]

1. yes
2. yes but that's not the point: How should the environment variables look like? If they are global and have the same name, they will overwrite each other.

[madoar]

Is this really a problem?
I mean if we take variables like TYPE_ID or CATEGORY_ID as global variables, aren't they constants and don't change independent of how many times you load them for a single script?

[plata]

Sure but that doesn't help at all. If we want to use resources for verbs we need something like APPLICATION_ID for the verb (and for every included verb).

[madoar]

In addition I think we should move the location, where we set TYPE_ID, CATEGORY_ID, APPLICATION_ID and SCRIPT_ID from inside the AppsController class to a new EngineInjector class, to be more consistent, with the other injected functionality (i.e. include, Bean, tr, ...).

[madoar]

So you mean we would need to add a kind of VERB_ID variable?
I'm not sure why we would need such a variable?

[plata]

The purpose of all this is to access resources which are located relative to a verb. To to this, we need a VERB_ID (doesn't help if we know where the application is located).

[plata]

In the end this whole approach is a bit pointless anyways because you can simply use the same strings which are used in the include to get the resource.

[madoar]

Yes.
I'm not sure if location is something, which should be injected from outside.
I mean when writing a verb or script, I know where it's located (in the include syntax).

[plata]

Exactly. However, it is important to notice that this works only because verbs do not have special characters in their names.

[plata]

I saw earlier on that Lutris does not only have a name for a script but also a slug (what we would call "id"). If we would do something similar, we could just include by using that id. This would also make the fixed 4 level namespace unnecessary.