Null support (#89)

* Added null support (hopefully)

Author: daDevBoat

my-app/src/model.js

@@ -88,17 +88,17 @@ export const model = {
         entries.forEach(entry => {
             const course = {
                 code: entry[1].code,
-                name: entry[1]?.name ?? "null",
-                location: entry[1]?.location ?? "null",
-                department: entry[1]?.department ?? "null",
-                language: entry[1]?.language ?? "null",
-                description: entry[1]?.description ?? "null",
-                academicLevel: entry[1]?.academic_level ?? "null",
-                period: entry[1]?.period ?? "null",
+                name: entry[1]?.name ?? null,
+                location: entry[1]?.location ?? null,
+                department: entry[1]?.department ?? null,
+                language: entry[1]?.language ?? null,
+                description: entry[1]?.description ?? null,
+                academicLevel: entry[1]?.academic_level ?? null,
+                period: entry[1]?.period ?? null,
                 credits: entry[1]?.credits ?? 0,
-                prerequisites: entry[1]?.prerequisites ?? "null",
-                prerequisites_text: entry[1]?.prerequisites_text ?? "null",
-                learning_outcomes: entry[1]?.learning_outcomes ?? "null"
+                prerequisites: entry[1]?.prerequisites ?? null,
+                prerequisites_text: entry[1]?.prerequisites_text ?? null,
+                learning_outcomes: entry[1]?.learning_outcomes ?? null
             };
             this.addCourse(course);
         });

my-app/src/presenters/PrerequisitePresenter.jsx

@@ -394,7 +394,7 @@ export const PrerequisitePresenter = observer((props) => {
     function loadTree() {
 
         console.log(JSON.stringify(props.selectedCourse.prerequisites, null, 4));
-        if (props.selectedCourse.prerequisites === "null" || props.selectedCourse.prerequisites.length == 0) {
+        if (!props.selectedCourse?.prerequisites || props.selectedCourse.prerequisites.length == 0) {
             let display_node = createNode("No Prerequisites", "No Prerequisites", "default");
             display_node.style["pointerEvents"] = "none";
             display_node["className"] = 'no-handles';

my-app/src/presenters/SearchbarPresenter.jsx

@@ -15,7 +15,7 @@ const SearchbarPresenter = observer(({ model }) => {
         const searchResults = model.filteredCourses.filter(course =>
             course.code.toLowerCase().includes(query.toLowerCase()) ||
             course.name.toLowerCase().includes(query.toLowerCase()) ||
-            course.description.toLowerCase().includes(query.toLowerCase())
+            course.description?.toLowerCase().includes(query.toLowerCase())
         );
         model.setCurrentSearchText(query);
         model.setCurrentSearch(searchResults);

my-app/src/views/ListView.jsx

@@ -111,11 +111,11 @@ function ListView(props) {
                                         className="text-gray-600"
                                         dangerouslySetInnerHTML={{
                                             __html: readMore[course.code]
-                                                ? course.description
-                                                : (course.description.slice(0, 200)+"..."),
+                                                ? course?.description
+                                                : (course?.description?.slice(0, 200)+"..."),
                                         }}
                                     />
-                                    {course.description.length > 150 && (
+                                    {course?.description?.length > 150 && (
                                         <span
                                             className="text-blue-500 cursor-pointer"
                                             onClick={(e) => {