Revize 3f66b624

Comments added to selection utils

webapp/utils/selectionUtils.ts

@@ -7 +7 @@
     endPositionOriginalDocument: number;
     selectionLengthOriginalDocument: number;
 }
+const idAttributeName = 'aswi-tag-id';
+
 export function GetSelectionInfo(annotation: AnnotationInfo): SelectionInfo | null {
     const selection = window.getSelection();
     if (!selection) {
         return null;
     }
+
     if (!annotation?.tagStartPositions || !annotation.tagLengths) {
+        // invalid data provided from API
         console.log('start or lengths not found');
         return null;
     }
 
-    let startTag = selection.anchorNode;
-    let endTag = selection.focusNode;
+    let startTag = selection.anchorNode; // anchor node = node where selection started
+    let endTag = selection.focusNode; // focus node = node where selection ended
 
     if (!startTag || !endTag) {
         console.log('Selection not found');
@@ -26 +30 @@
     }
 
     if (startTag.nodeName.includes('#')) {
+        // it is not an element (usually #text)
         startTag = startTag.parentNode;
     }
     if (endTag.nodeName.includes('#')) {
+        // it is not an element (usually #text)
         endTag = endTag.parentNode;
     }
+
     if (!startTag || !endTag) {
         console.log('Selection element not found');
         return null;
@@ -48 +55 @@
     let startElement = startTag as Element;
     let endElement = endTag as Element;
 
-    let startId: number = Number(startElement.getAttribute('aswi-tag-id')) ?? -1;
-    let endId: number = Number(endElement.getAttribute('aswi-tag-id')) ?? -1;
+    let startId: number = Number(startElement.getAttribute(idAttributeName)) ?? -1;
+    let endId: number = Number(endElement.getAttribute(idAttributeName)) ?? -1;
 
     let startPosition =
         annotation.tagStartPositions[startId] +