I know that we can to get status from the REST API by GET request.
If item was changed then in my php page I want to see this changes whithout refresh page
I miss a lot of elements in the OpenHab.
For Example, I want this element
You should probably look at how HABpanel works, then you can write your own UI.
How to make my own item in HABpanel?
But I would like to write/develop HTML code, the flexibility of PHP and JS.
To make your own, rossko57 is telling you to look at an example that already works and make yours work like that. Pay particular attention to the parts of the code that make up HABPanel (or BasicUI or ClassicUI) that deal with the Web Socket subscription and processing.
Oh… Now I fet it.
Where to find examples or lessons?
Ever tried to search for “Habpanel Widget” ?? As simpel as that.
If you are building your own UI, you will have to search Google for generic examples and lessons for how to use a websocket. You can look at the source code for HABPanel, BasicUI, and ClassicUI for three examples for how to use openHAB’s web socket. For the rest you are on your own.
Take a look also at Server-Sent Events (SSE) .
It allows a web page to get updates from a server.