Hello
I’m a novice plug-in developer.
I have a question for you.
I only know that Ruby Language can create extended plug-ins.
What I want to do is use the .skp file to create data from sketchups (length, width, width, etc.)
I would like to develop it in conjunction with the web framework and DataBase.
For example, the .skp file in the sketchup might contain data designed by the sketchup.
If you upload this file from the web, you can automatically pull the data from the web, insert it into the DataBase, and spray the data from the homepage.
I want to make it, can you recommend a web programming language that I think is possible? (ex : JSP, NET, Ruby on Rails, etc)
However, as far as I know, I heard that skp files cannot be used as rubies and can only be used in C or C++ languages.
I’ve been searching Google, but it’s hard to find an example of this development, so I asked you a question. I’d appreciate your answer.
Have a nice day. 
I’m not sure whether what you want to develop really is a plugin/extension. An extension runs inside SketchUp (it is controlled by SketchUp) and is written in Ruby and uses SketchUp’s Ruby API. SketchUp’s API can only be accessed in SketchUp, not from stand-alone Ruby scripts.
If I understand your plan, you want to develop your own web application that reads data out of skp files. For this purpose, you do not want to run SketchUp as a graphical application because it waits for user input, you want your application to have control.
Alternatively, SketchUp offers an SDK for reading and writing skp files. This is not the same as the Ruby API (which is for creating interactive tools). This is nothing more than reading files. You heard right, the SDK is unfortunately only available for C/C++.
Contrary to common belief, proprietary file formats like skp (SketchUp), psd (PhotoShop), doc etc. are not meant to be used for exchanging data, but to be opened by the exact same application (when you send such files to someone, the recipient does not always own this application). These file formats exist only so that they can store/restore exactly all features of that specific application.
Exchange file formats have been developed for storing the common denominator of proprietary file formats and are standardized, for example odp (text documents), obj (3D models), dae (Collada 3D models), stl (3D models for printing), glTF (3D scenes for web, media, games).
So your options are:
- Use the SketchUp SDK and learn C/C++, or find a way to call C+/C++ functions from another language.
- Design your application so that users provide data in a much more preferable exchange format, for which you can find plenty of libraries in many languages, for example JavaScript, NET, Ruby.