How to use a if statement in a div using thymeleaf? - html

Question

If I remove the div tag from the source code below my application runs with no error. But it displays an empty cell (which is correct). I just want to hide this if the cells are empty.
Thymeleaf html
<div th:object="${AppPortModel.Status}" th:if="${AppPortModel.Status} == 'CRITICAL'">
<h3>
MONITORING
</h3>
<table id ="apCritTable">
<thead>
<tr>
<th> Status </th>
<th> HostName </th>
<th> Port Name</th>
<th> Port Listening Count </th>
</tr>
</thead>
<tbody>
<tr th:each="AppPortModel, iterStat : ${showap}" th:if="${AppPortModel.Status == 'CRITICAL'}">
<td th:text ="${AppPortModel.Status}"></td>
<td th:text="${AppPortModel.host}">${AppPortModel.host}</td>
<td th:text="${AppPortModel.portOwner}"></td>
<td th:text="${AppPortModel.count}"></td>
</tr>
</tbody>
</table>
</div>
AppPortModel
public class AppPortModel implements Comparable {
private String Status;
private String host;
private String portName;
private String plCount;
//getters and setters
#Override int compareTo(Object o) {
return //stuff
}
Controller
#Controller
public class IndexController {
#RequestMapping(value = "/", method = RequestMethod.GET)
public ModelAndView getdata() throws IOException {
ModelAndView model = new ModelAndView("index");
model.addObject("showap", apList);
return model;
}
AppPortList
#Component
public class AppPortList {
#Value("#{'$APP_SERVERS_PORT}'.split('#!')}")
private String[] apServerArray;
#Value("#{'${APP_SERVER_MONITORING_LIST}'.split('#!')}")
private String[] appServerPortsList;
#PostConstruct
public List<AppPortModel> getAppPortList() {
final int MYTHREADS = 80;
ExecutorService executor = Executors.newFixedThreadPool(MYTHREADS);
ApplicationPort.resetData();
try {
for (int z = 0; z < apServerArray.length; z++) {
String apServer = apServerArray[z];
String[] portListArray=appServerPortsList[z].split(",");
ApplicationPort apWorker = new ApplicationPort(apServer, portListArray);
executor.execute(apWorker);
}
} catch(ArrayIndexOutOfBoundsException e) {
System.out.println("ArrayIndexOutOfBoundsException in AppPortList");
}
finally {
executor.shutdown();
while (!executor.isTerminated()) {
}
logger.info("\nFinished all threads in App Port. ");
}
return ApplicationPort.getData();
}
Snippet of Class App
static List<AppPortModel> apData = new ArrayList<AppPortModel>();
public static List<AppPortModel> getData() {
return apData;
}
public static void setData(List<AppPortModel> apData) {
ApplicationPort.apData = apData;
}
public static void resetData(){
apData = new ArrayList<AppPortModel>();
}
public ApplicationPort(String apServer, String[] portListArray) {
this.apServer = apServer;
this.portListArray = portListArray;
}
This table will populate if AppPortModel.Status is CRITICAL. I am trying to hide this table if there is no values in this table. If I just have a regular div tag my code will run but I will have a awkward head and table row heads on my page with empty cells.
Attempt
I tried adding some th logic into my div tag, but I receive an null error.
<div th:object="${AppPortModel.Status}" th:if="${AppPortModel.Status == 'CRITICAL'}">
Attempt 2
<div th:if="${Status} == 'CRITICAL'">
This script would hide my div tag. Even if I have Status = to CRITICAL it would still hide the table.

Answer 1

You can check whether the list is empty using the following condition expression. Assuming the object showap is a List type,
<div th:if="${not #lists.isEmpty(showap)}">
--content--
</div>
Your h3 tag and table goes inside this div.
#lists is a thymeleaf utility class. Refer http://www.thymeleaf.org/apidocs/thymeleaf/2.0.2/org/thymeleaf/expression/Lists.html for more options. You can alternatively use size() method and check for list length.