feat: Trigger beforeInputUpdate when a candidate is selected in candidate box

src/lib/components/Keyboard.ts

@@ -393,6 +393,13 @@ class SimpleKeyboard {
             candidateStr = selectedCandidate.normalize("NFD");
           }
 
+          /**
+           * Perform an action before any input change
+           */
+          if (typeof this.options.beforeInputUpdate === "function") {
+            this.options.beforeInputUpdate(this);
+          }
+
           const currentInput = this.getInput(this.options.inputName, true);
           const initialCaretPosition = this.getCaretPositionEnd() || 0;
           const inputSubstr =

src/lib/components/tests/CandidateBox.test.js

@@ -371,6 +371,41 @@ it('CandidateBox selection should trigger onChange', () => {
   keyboard.destroy();
 });
 
+it('CandidateBox selection should trigger beforeInputChange', () => {
+  const keyboard = new Keyboard({
+    layout: {
+      default: [
+        "a b {bksp}"
+      ]
+    },
+    layoutCandidates: {
+      a: "1 2 3 4 5 6"
+    },
+    beforeInputUpdate: jest.fn(),
+  });
+
+  let candidateBoxOnItemSelected;
+  
+  const onSelect = jest.fn().mockImplementation((selectedCandidate) => {
+    candidateBoxOnItemSelected(selectedCandidate);
+    keyboard.candidateBox.destroy();
+  });
+
+  const candidateBoxRenderFn = keyboard.candidateBox.renderPage;
+  
+  jest.spyOn(keyboard.candidateBox, "renderPage").mockImplementation((params) => {
+    candidateBoxOnItemSelected = params.onItemSelected;
+    params.onItemSelected = onSelect;
+    candidateBoxRenderFn(params);
+  });
+
+  keyboard.getButtonElement("a").click();
+  keyboard.candidateBox.candidateBoxElement.querySelector("li").click();
+
+  expect(keyboard.options.beforeInputUpdate.mock.calls[0][0]).toMatchObject(keyboard);
+  keyboard.destroy();
+});
+
 it('CandidateBox normalization will work', () => {
   const keyboard = new Keyboard({
     layout: {