The webpage can warn them with <noscript></noscript> content.
For example, why send data to the server, when certain functions can be taken care of client-side?
Let me see .. How many times have you mentioned Opera and F12 now, papabaer? ;)
but what is "absolutely necessary?". We use js to deliver real time news headlines. It degrades gracefully with no js, leaving no indication that anything is missing. However the user experience misses a lot. These are not out of the box Moreover feeds but basically js renditions of our own news sources. We can also deliver by includes etc, but js has its advantages. Basically they dont know what they are missing even if its not "absoultely necessary". and i dont really want to place text messages suggesting they turn JS on.
Some of the news sites I visit require it... no problem. It's enabled.
yes papabear i agree that if someone has deliberately gone to the trouble to turn off js they will most porbably know how to turn it on again. Thats an excellent point. i just dont want to add a text to every one of our 200 pages with js news delivery that they should turn it on!
However no big issue really, we are gradually changing news delivery from js to internal parsing of RSS and then including the results as a PHP include. We have to move with the times.. and the advantages of losing popups compaared to losing js dynamic content to many browsers is the grim reality..