Question

I am making a menu with this HTML.

<div class="sidemenu-maincat">
    <img src="folder/maincat1.jpg" alt="Main cat1" id="toggle" />
</div>

<div class="sidemenu-subcat">
    <a href="submenu11.html"> - Submenu 11 </a>
</div>
<div class="sidemenu-subcat">
    <a href="submenu12.html"> - Submenu 12 </a>
</div>
<div class="sidemenu-subcat">
    <a href="submenu13.html"> - Submenu 13 </a>
</div>     

<div class="sidemenu-maincat">
    <img src="folder/main-cat2.jpg" alt="Main cat2 /> 
</div>

<div class="sidemenu-subcat">
    <a href="submenu21.html"> > Submenu 21 </a>
</div>
<div class="sidemenu-subcat">
    <a href="submenu22.html"> > Submenu 22 </a>
</div>
<div class="sidemenu-subcat">
    <a href="submenu23.html"> > Submenu 23 </a>
</div> 

I have the “sidemenu-subcat” div hidden and I would like it to show/hide when I press the pictures on in the “sidemenu-maincat” divs. I have tried to do this with Javascript but I can’t figure out how at all. I would like it not to be done with any library.

I’m keeping all my Javascripts in another document and this is the closest I’ve come to solve my problem:

function toggling()
{
    if(document.getElementByClassName("hidden").style.display == "none")
    {
        document.getElementByClassName("hidden") = "block";    
    }
    else
    {
        document.getElementByClassName("hidden") = "none"; 
    }
}

function init()
{
    var toggle = document.getElementsByClassName("toggle");
    toggle.onclick = toggling;
}

I know it’s far from what that needs to be done but it’s the closest I’ve got..

Answer 1

Well I do prefer to use a library for this type of thing but I put together a pure javascript example for you. Though there is probably a better way to do it.

Firstly, each submenu should be contained within the it’s maincat div and given a hidden class so it is hidden on page load.

Working Example

.sidemenu-subcat.hidden {
    display: none;  
}

var sideMenuOptions = document.getElementsByClassName('sidemenu-maincat');
for (var i = 0; i < sideMenuOptions.length; i++) {
  sideMenuOptions[i].addEventListener('click', function() {
    var subMenuItems = this.getElementsByClassName('sidemenu-subcat');
    for (var s = 0; s < subMenuItems.length; s++) {
      var subItem = subMenuItems[s];
      // if the element is not visible it's offsets will be 0
      if (subItem.offsetWidth === 0 && subItem.offsetHeight === 0) {
        subItem.className = 'sidemenu-subcat';
      } else {
        subItem.className = subItem.className + ' hidden';
      }
    }
  });
}