Merge pull request #201 from mp-access/return-time-frame-on-publish

`/publish` endpoint adjustment

Author: patsalv

src/main/kotlin/ch/uzh/ifi/access/controller/ExampleController.kt

@@ -170,27 +170,36 @@ class ExampleController(
         @PathVariable course: String,
         @PathVariable example: String,
         @RequestBody body: ExampleDurationDTO,
-    ) {
+    ):ExamplePublicationDTO {
         val activeExample = exampleService.getExamples(course).firstOrNull {
             it.status == TaskStatus.Interactive
         }
 
         if (activeExample != null) {
             throw ResponseStatusException(
-                HttpStatus.NOT_FOUND,
+                HttpStatus.CONFLICT,
                 "An interactive example already exists."
             )
         }
 
         val updatedExample = exampleService.publishExampleBySlug(course, example, body.duration)
 
+        val start = updatedExample.start
+        val end = updatedExample.end
+
+        if (start == null || end == null) {
+            throw ResponseStatusException(HttpStatus.INTERNAL_SERVER_ERROR, "Published example is missing required start or end time.")
+        }
+
         emitterService.sendPayload(EmitterType.STUDENT, course, "redirect", "/courses/$course/examples/$example")
         emitterService.sendPayload(
             EmitterType.EVERYONE,
             course,
             "timer-update",
-            "${updatedExample.start}/${updatedExample.end}"
+            "${start}/${end}"
         )
+
+        return ExamplePublicationDTO(start, end)
     }
 
     // Invoked by the teacher when want to extend the time of an active example by a certain amount of seconds

src/main/kotlin/ch/uzh/ifi/access/model/dto/ExamplePublicationDTO.kt

@@ -0,0 +1,8 @@
+package ch.uzh.ifi.access.model.dto
+
+import java.time.LocalDateTime
+
+data class ExamplePublicationDTO (
+    val startDate: LocalDateTime,
+    val endDate:LocalDateTime
+)