Can I use certain client-side Javascript APIs server-side?

Question

I'm looking at some APIs which are meant to be used in a web browser. They require the inclusion of their .js code and then present you with an API that returns audio. Restating this in a more general way, these APIs return some stream of bytes (audio in this case) which the browser plays.

Can APIs of this type be used in server-side Javascript frameworks, eg. Node, where I make the API call and capture the resulting binary data in some variable? I'm not sure I know how to map the semantics of what's going on in the browser to a server-side solution.

Here's an arbitrary example http://responsivevoice.org/api/

You include their Javascript in your page and then call sampleLibrary.speak("hello world"); . This results in audio coming back to the browser which is played.

Answer 1

Generally many JavaScript's created for the browser can be run, but you have to mock a lot of browser functionality.

I took a look at the library you were linking to. Beautified it, and made some changes to it to make it a node module. Then you have to mock navigator.userAgent , window and document .

For document the library is using addEventListener . After mocking those I'm getting RV: Voice synthesis not supported . The library is using Web Speech API through Window.speechSynthesis . This is not possible to mock.

It does however have a fallback functionality, which is to insert AUDIO tags through createElement . You will then get urls for generated audio files. Then you might be able to download these and do what you wanted to do on your server.