openfoodnetwork/app/webpacker/controllers/checked_controller.js

import { Controller } from "stimulus";

export default class extends Controller {
  static targets = ["all", "checkbox", "disable"];
  static values = { count: Number };

  connect() {
    this.toggleCheckbox();
  }

  toggleAll() {
    this.checkboxTargets.forEach((checkbox) => {
      checkbox.checked = this.allTarget.checked;
    });

    this.countValue = this.allTarget.checked ? this.checkboxTargets.length : 0;

    this.#toggleDisabled();
  }

  toggleCheckbox() {
    this.countValue = this.#checkedCount();
    this.allTarget.checked = this.#allChecked();

    this.#toggleDisabled();
  }

  countValueChanged() {
    window.dispatchEvent(
      new CustomEvent("checked:updated", { detail: { count: this.countValue } })
    );
  }

  // private

  #checkedCount() {
    return this.checkboxTargets.filter((checkbox) => checkbox.checked).length;
  }

  #allChecked() {
    return this.countValue === this.checkboxTargets.length;
  }

  #toggleDisabled() {
    if (!this.hasDisableTarget) {
      return;
    }

    if (this.#checkedCount() === 0) {
      this.disableTargets.forEach((element) => element.classList.add("disabled"));
    } else {
      this.disableTargets.forEach((element) => element.classList.remove("disabled"));
    }
  }
}