How do I check if a specific module has been added to a Worklet?

Question

I'm working with AudioWorkletNode and, to use it, it requires you to first load a processor module on the audio_context.audioWorklet .

DOMException: Failed to construct 'AudioWorkletNode': AudioWorkletNode cannot be created: AudioWorklet does not have a valid AudioWorkletGlobalScope. Load a script via audioWorklet.addModule() first.

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Due to the modular nature of my code, I need a reliable way to prevent the unnecessary multiple loading of the processor module; not to .addModule if already done to a given AudioContext . Is there such a way other than try - catch ing and marking on the AudioContext object?

Answer 1

Let's say you have named your processor my-processor and the definition of your AudioWorkletProcessor looks somehow like this:

class MyProcessor extends AudioWorkletProcessor {

    process () {
        return true;
    }

}

registerProcessor('my-processor', MyProcessor);

To check if that processor is already loaded you can do something like this from within the main thread:

// somewhere inside of an async function ...

let audioWorkletNode;

try {
    audioWorkletNode = new AudioWorkletNode(audioContext, 'my-processor');
} catch (err) {
    await audioContext.audioWorklet.addModule('./worklet.js');

    audioWorkletNode = new AudioWorkletNode(audioContext, 'my-processor');
}

The code is using a try / catch block but it does at least not load the JS file if it was already loaded before.