From 1ed16d75d3d56965e146f29cb8e5dc0fa8e1930d Mon Sep 17 00:00:00 2001
From: Valentina Kiryushkina <valentina.kiryushkina@jetbrains.com>
Date: Mon, 19 Dec 2016 12:49:27 +0300
Subject: [PATCH] Do not save empty choice parameters for non-choice tasks

---
 .../com/jetbrains/edu/learning/courseFormat/Task.java  | 10 ++++++++--
 .../learning/stepic/EduAdaptiveStepicConnector.java    |  2 +-
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/python/educational-core/student/src/com/jetbrains/edu/learning/courseFormat/Task.java b/python/educational-core/student/src/com/jetbrains/edu/learning/courseFormat/Task.java
index e525e3e604f5..6cd8083dcecd 100644
--- a/python/educational-core/student/src/com/jetbrains/edu/learning/courseFormat/Task.java
+++ b/python/educational-core/student/src/com/jetbrains/edu/learning/courseFormat/Task.java
@@ -44,7 +44,7 @@ public class Task implements StudyItem {
   @Transient private Lesson myLesson;
   @Expose @SerializedName("update_date") private Date myUpdateDate;
 
-  @Expose @SerializedName("choice_parameters") private ChoiceParameters myChoiceParameters = new ChoiceParameters();
+  @Expose @SerializedName("choice_parameters") private ChoiceParameters myChoiceParameters;
   private int myActiveSubtaskIndex = 0;
   @SerializedName("last_subtask_index")
   @Expose private int myLastSubtaskIndex = 0;
@@ -54,6 +54,12 @@ public class Task implements StudyItem {
   public Task(@NotNull final String name) {
     this.name = name;
   }
+  
+  public static Task createChoiceTask(@NotNull String name) {
+    final Task task = new Task(name);
+    task.setChoiceParameters(new ChoiceParameters());
+    return task;
+  }
 
   /**
    * Initializes state of task file
@@ -326,7 +332,7 @@ public class Task implements StudyItem {
   }
   
   public boolean isChoiceTask() {
-    return !myChoiceParameters.getChoiceVariants().isEmpty();
+    return myChoiceParameters != null;
   }
 
   // used for serialization
diff --git a/python/educational-core/student/src/com/jetbrains/edu/learning/stepic/EduAdaptiveStepicConnector.java b/python/educational-core/student/src/com/jetbrains/edu/learning/stepic/EduAdaptiveStepicConnector.java
index ef9e9e156ab1..76f3e388b7ac 100644
--- a/python/educational-core/student/src/com/jetbrains/edu/learning/stepic/EduAdaptiveStepicConnector.java
+++ b/python/educational-core/student/src/com/jetbrains/edu/learning/stepic/EduAdaptiveStepicConnector.java
@@ -156,7 +156,7 @@ public class EduAdaptiveStepicConnector {
                                             @NotNull String lessonName,
                                             @NotNull StepicWrappers.Step block,
                                             int stepId) {
-    final Task task = new Task(lessonName);
+    final Task task = Task.createChoiceTask(lessonName);
     task.setStepId(stepId);
     task.setText(block.text);