Disable image reloading on web server

Projects Programming
1

Hello,

I am in the process of designing a web server, using Mega2560+Ethernet shield. The webpage index and images are taken from the SD card, plugged in the ethernet shield. All loads good.

The problem I am having is that, some images have to change, in relation to some sensor values (is a graphical function flow). How can I accomplish that, without reloading the entire page ? Text values I can reload using Ajax but how about images ?

I tried also auto-refreshing the page, but it takes time for all the images to load. I can't convince Chrome to load from cache the images that are not changed...

I am open for ideas.

2

it's not an Arduino question....

usually image caching is the decision of the client side, not for the server side to impose, the Server can only "suggest", the browser decides.

Browser caching strategies can be controlled by HTTP headers. They are just a hint to the browser and since browsers are terribly inconsistent, you'll probably need several headers to get the desired effect supported on different browsers. probably need to explore Cache-Control as well

And You can also look at the expires http header