SharePoint Online Workbench Question

Question

I am very new to the SharePoint Online and I was following below tutorial on Youtube from Microsoft

https://www.youtube.com/watch?v=QbDtsMg88Js&list=PLR9nK3mnD-OXvSWvS2zglCzz4iplhVrKq&index=2

It don't have any issue with it. It works as it mentioned. It help me lot to understand and learn. But I stuck at one point where I like to have more explanation.

At 21:48 of the video, he open the O365 and open workbench.aspx page add the locally created webpart on O365. I like to know how automatically without doing anything webpart was appear on O365.

Actually I follow same and it works for me to same, as it was explain It came to my O365 too. But I was looking for more explanation, if somebody can.

Answer 1

When you run the command gulp serve it builds the solution and copy the assets and starts the service. If you see your command prompt there is API server running in the background to serve the web parts to O365 workbench from the localhost.

If you stop the server by clicking CTRL + C you lost the web parts from the WebParts toolbox list on the O365 page. You will see the below warning message.