getting the EVENT parameter with eventListener while using Bind method (class)

Question

I am using addBtn.on('click', list.addItem.bind(list));. How can I get the event parameter so that I can implement the event.preventDefault() inside addItem(){}. is there a way to do that?

const addBtn = $('#addBtn'),
  itemListText = $('#itemListText'),
  textInput = $('#addToListInput');

class Lists {
  constructor() {
    this.currentList = [];
  }

  currentListCount() {
    return this.currentList.length;
  }

  addItem() {
    if (textInput.val().length > 0)
      this.currentList.push({
        item: textInput.val(),
        checked: 'false',
      });

    itemListText.text(`Item List (${this.currentListCount()})`);
    textInput.val('');
  }
}

const list = new Lists();

addBtn.on('click', list.addItem.bind(list));

Answer 1

You do it exactly the way you would have done it without using bind: by accepting the parameter:

addItem(event) {
    // ...use `event.preventDefault()` etc. here...
}

The function bind returns calls the original function with all of the arguments it receives, so it passes the event to your method.

Live Example:

const addBtn = $('#addBtn'),
  itemListText = $('#itemListText'),
  textInput = $('#addToListInput');

class Lists {
  constructor() {
    this.currentList = [];
  }

  currentListCount() {
    return this.currentList.length;
  }

  addItem(event) {
    event.stopPropagation();
    if (textInput.val().length > 0)
      this.currentList.push({
        item: textInput.val(),
        checked: 'false',
      });

    itemListText.text(`Item List (${this.currentListCount()})`);
    textInput.val('');
  }
}

const list = new Lists();

addBtn.on('click', list.addItem.bind(list));

$("#wrapper").on("click", () => {
    console.log("Wrapper saw click event");
});

All of the elements below are in a wrapper that logs when it sees a click. Notice that it sees clicks every except when you click the Add button, because the Add button uses <code>stopPropagation</code> on the event object it receives.
<div id="wrapper">
  <div id="itemListText">Item List (0)</div>
  <input type="text" id="addToListInput">
  <input type="button" id="addBtn" value="Add">
</div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>