How to add submenu on hover effect in left navigation in magento? - magento

Question

I have vertnav/left.phtml file code,
<div class="vertnav-container">
<div class="">
<h4 class="no-display"><?php echo $this->__('Category Navigation:') ?></h4>
<?php $store_categories = $this->toLinearArray($this->getStoreCategories()) ?>
<?php if ($count = count($store_categories)): ?>
<ul id="vertnav">
<?php endif; ?>
<?php foreach ($store_categories as $i => $_category): ?><?php $class = array() ?>
<?php if ($count == 1): ?>
<?php $class[] = 'only' ?>
<?php elseif (! $i): ?>
<?php $class[] = 'first' ?>
<?php elseif ($i == $count-1): ?>
<?php $class[] = 'last' ?>
<?php if (isset($store_categories[$i+1]) && $this->isCategoryActive($store_categories[$i+1])) $class[] = 'prev'; ?>
<?php if (isset($store_categories[$i-1]) && $this->isCategoryActive($store_categories[$i-1])) $class[] = 'next'; ?>
<?php echo $this->drawOpenCategoryItem($_category, 0, $class) ?>
<?php endforeach ?>
<?php if ($count): ?>
</ul>
<?php endif; ?>
</div>
</div>
and set System > Configuration > Catalog > Category Vertical Navigation to 2 as per my requirement, but now on mouseover on that displayed category subcategories should be shown
so how can i do customization to that and add hover effect code to this?
Please help me

Answer 1

If you take a closer look at the drawOpenCategoryItem of the Mage_Catalog_Block_Navigation you might notice that the method does a check whether the given category is part of the current category path. So only when this check returns true, the children categories of this category will be rendered. For other categories the script will not go into that part of the code.
This sounds to be case if I understand your question correctly.
if (in_array($category->getId(), $this->getCurrentCategoryPath())){
$children = $category->getChildren();
$hasChildren = $children && $children->count();
if ($hasChildren) {
$htmlChildren = '';
foreach ($children as $child) {
$htmlChildren.= $this->drawOpenCategoryItem($child);
}
if (!empty($htmlChildren)) {
$html.= '<ul>'."\n"
.$htmlChildren
.'</ul>';
}
}
}
Additional to this information. The drawOpenCategoryItem() is never actually called upon in the whole PHP codebase.
So to have these rollover effects you need to have code that generates the full tree structure, or at least a big enough part of it. Regarding the System > Configuration > Catalog > Category Vertical Navigation. I guess you customized that yourself?
To give you a few pointers. You might want to have a look at the following methods. These are used for the rendering of the top menu and are actually doing the thing you are planning to implement.
Mage_Catalog_Block_Navigation::renderCategoriesMenuHtml()
Mage_Catalog_Block_Navigation::_renderCategoryMenuItemHtml()
Hopes this helps you getting things underway.