luci-app-adguardhome/luasrc/view/AdGuardHome/AdGuardHome_check.htm

<%+cbi/valueheader%>
<%fs=require"nixio.fs"%>
<input type="button" class="cbi-button cbi-button-apply" id="apply_update_button" value="<%:Update core version%>" onclick=" return apply_update() "/>
<% if self.showfastconfig then %>
<input type="button" class="cbi-button cbi-button-apply" id="to_configpage" value="<%:Fast config%>" onclick="location.href='<%=url([[admin]], [[services]], [[AdGuardHome]], [[manual]])%>'"/>
<%end%>
<textarea id="cbid.logview.1.conf" class="cbi-input-textarea" style="width: 100%;display:none" data-update="change" rows="5" cols="60" readonly="readonly" > </textarea>
<script type="text/javascript">//<![CDATA[
function apply_update(){
	XHR.get('<%=url([[admin]], [[services]], [[AdGuardHome]], [[doupdate]])%>',null,function(x, data){}
		);
	var	btn = document.getElementById('apply_update_button');
	btn.disabled = true;
	btn.value    = '<%:Check...%>';
	poll_check();
	return
}
function poll_check(){
var lv = document.getElementById('cbid.logview.1.conf');
	lv.style.display="inline"
XHR.poll(3, '<%=url([[admin]], [[services]], [[AdGuardHome]], [[check]])%>', null,
	function(x, data) {
		var lv = document.getElementById('cbid.logview.1.conf');
		if (x.responseText && lv) {
			if (x.responseText=="\u0000")
			{
				for(j = 0,len=this.XHR._q.length; j < len; j++) {
				if (this.XHR._q[j].url == '<%=url([[admin]], [[services]], [[AdGuardHome]], [[check]])%>')
				{
				this.XHR._q.splice(j,1);
				var	btn = document.getElementById('apply_update_button');
				btn.disabled = false;
				btn.value    = '<%:Updated%>';
				document.getElementById('updateversion').innerText='<%=uci:get("AdGuardHome","AdGuardHome","version")%>'
				}
				}
				return	
			}
			lv.innerHTML += x.responseText; 
		}
	}
);}
<% if fs.access("/var/run/update_core") then %>
var	btn = document.getElementById('apply_update_button');
	btn.disabled = true;
	btn.value    = '<%:Check...%>';
poll_check();
<%elseif fs.access("/var/run/update_core_error") then %>
poll_check();
<%else%>
var	btn = document.getElementById('apply_update_button');
	btn.value    = '<%:Update core version%>';
<%end%>
//]]>
</script>
<%+cbi/valuefooter%>