WAB widget example to use third-party JS libraries
Since I couldn't understand ArcGIS documentation and could not find much help online, I made this quick Web AppBuilder for ArcGIS widget to show how to add third-party libraries to them so widgets can be standalone.
Once solved it was pretty obvious but ¯\_(ツ)_/¯
I picked to add ClipboardJS as an example:
Inside the widget folder create a new folder libs and copy the libraries you need
Open Widget.js and add './widgets/thirdparty-wab/libs/mylibrary.js'. In this case I used:
'./widgets/thirdparty-wab/libs/clipboard.min.js'
Don't forget to include it in the function in the correct order function (..., Mylibrary) if you need to reference it in your widget JS code:
function(declare, BaseWidget, ClipboardJS)
Of course you could use any other folder or folder name as long as it exists within the widget folder and you load it correctly.
And that's it.