A polyfill is code that fills in functionality missing from the older browser. For example, Internet Explorer does not have Promise like other modern browsers. In this case, we can use a promise polyfill so that the code that uses Promise can work in IE. There are two ways of …

I had an interesting problem with Promise Polyfill to make promise and finally work on IE11. The page has multiple JS bundles. The existing JS bundles all had Promise polyfill from older version of core-js (babel-core@7.0.0-bridge.0). import ‘core-js/es6/promise’; Then, I added another JS bundle with the latest Promise polyfill. The …

I recently built a chat widget that supports Amazon Connect Chatbot with amazon-connect-chatjs. It turned out the library does not support IE11 (see the issue I raised here). The good news is that if we add polyfills, we can make it work. AWS will probably update the library with IE …

By using the HTML audio element, we can embed sound in documents. When your app in running in a server, we can add audio files and refer to the paths in the audio element’s src attribute. What if you are creating an JS bundle that can be injected into a …

We can optimise the load time by using different image sizes for different screen widths. There is no point in loading a huge image for a mobile when the width is only for 200px. Here is the quick Python script to resize images. By changing the array, you can output …