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TypeScript type metadata symbols and interfaces #3148
Description
I have some questions about the metadata symbols that are added by the TypeScript compiler to the generated JavaScript code when using the --emitDecoratorMetadata flag and decorators.
I'm aware of:
"design:type"[The serialized form of the type of ?] the decorator target"design:paramtypes"[The serialized form of ?] the return type of the decorator target if it is a function type, undefined otherwise."design:returntype"A list of [serialized ?] types of the decorator target’s arguments if it is a function type, undefined otherwise.
Is the "design:name" symbol is available?
"design:name"The name of the decorator target
I'm hoping to find a symbol that will add the reflect-metadata that I need. I think I'm looking for something that is not available, something like design:implementedtypes or design:interfaces.
What I want to be able to do is be to get the names of the implemented interfaces.
@somedecorator
class Ninja implements INinja, IWarrior {
// ...
}
The metadata that I would like to be added by the compiler is something would be something like the following:
Reflect.metadata("design:implementedtypes", ["INinja","IWarrior "]);
As an alternative (I don't know if that is the case) it would be OK for me if the "design:type" added the interfaces as well.
Reflect.metadata("design:type", ["Ninja", "INinja","IWarrior"]);
Also, are the serialized form of the types emitted?
reflect.metadata("design:type", ["Ninja"]);
or the actual types?
reflect.metadata("design:type", [Ninja]);
Thanks
Activity
DanielRosenwasser commentedon May 14, 2015
Hey Remo H. Jansen (@remojansen), I'm not as familiar with decorators as some others on the team, but perhaps this comment may answer your question to some extent. If not, I can try to ping a few others from the team to help answer.
remojansen commentedon May 14, 2015
Daniel Rosenwasser (@DanielRosenwasser) thanks for the help.
I had a few questions and now I have some answers:
Object.But I still have some questions:
"design:name"symbol is available? This will return a string I assume?And I would like to get more people to think about this issue because in the issue above (#2305) I see that giancarloa said:
Maybe more developer feel this way and we need to consider some solution. Maybe the solution is a new metadata symbols like the one I was making up in my original question
"design:interfaces". I understand that you cannot return the interface as an object so maybe we instead of"design:interfaces"need string versions of all the currently available symbols, something like "design:stringified_type" which would generate["Ninja", "INinja","IWarrior"]forThanks
DanielRosenwasser commentedon May 14, 2015
The types of our decorators may help describe what you're interested in.
Ron Buckton (@rbuckton) can feel free to correct me.
I think the following #3015 (comment) is relevant.
rbuckton commentedon May 14, 2015
Remo H. Jansen (@remojansen) We are considering adding more type information. My current proposal can be found here.
remojansen commentedon May 14, 2015
Ron Buckton (@rbuckton) thanks for letting me know. I took a look to your proposal and I found what I need:
Do you have an open issue / proposal somewhere that I can follow to keep an eye on the updates regarding this topic? If there is an open issue / proposal already we can close this issue.
Thanks
DanielRosenwasser commentedon May 15, 2015
Hey Remo H. Jansen (@remojansen), I think the plan is to convert Ron Buckton (@rbuckton)'s proposal into a formal issue; not sure when we'll be doing that, so maybe we'll leave this open for now.
mhegazy commentedon Jun 12, 2015
looks like this is already covered here: #3015 (comment)