Thymeleaf: Refresh value with Ajax

Question

I have this piece of code in a Thymeleaf template.

 <div class="alert_counter" th:classappend="${numDeviceEventsWithAlarm>0} ?  show_info">
                                    <span th:text="${numDeviceEventsWithAlarm}">${numDeviceEventsWithAlarm}</span>
                                </div>

Is it possible to refresh the value numDeviceEventsWithAlarm using Ajax and without F5 ??

Answer 1

You can use the feature to only render a fragment of the Thymeleaf view.

First give the snippet of markup you want to update an id:

<span id="eventCount" th:text="${numDeviceEventsWithAlarm}"></span>

Then we can create a Spring request mapping in controller:

@RequestMapping(value="/event-count", method=RequestMethod.GET)
public String getEventCount(ModelMap map) {
    // TODO: retrieve the new value here so you can add it to model map
    map.addAttribute("numDeviceEventsWithAlarm", count);

    // change "myview" to the name of your view 
    return "myview :: #eventCount";
}

See Specifying fragments in controller return values in Thymeleaf manual to better understand the return that specifies which fragment to render.

Make a JavaScript function to update the value with ajax (jQuery style):

function updateEventCount() {
    $.get("event-count").done(function(fragment) { // get from controller
        $("#eventCount").replaceWith(fragment); // update snippet of page
    });
}

Then just call this function when you need to update the value.