All Category Listing In Magento

1. Display all the Magento Categories(Active/Inactive)

The following code will fetch all categories (both active and inactive) that are presented in your Magento Store.

$categories = Mage::getModel('catalog/category')
->getCollection()
->addAttributeToSelect('*');

2. Display All Active Categories

The following code will fetch all active categories that are present in your Magento Store. Filtering the inactive categories.

$categories = Mage::getModel('catalog/category')
->getCollection()
->addAttributeToSelect('*')
->addIsActiveFilter();

3. Display Active Categories Of Any Particular Level in Magento

The following code will fetch all active categories of certain/specific level. Here, I have chosen level 1. Also sorting categories by name.

$categories = Mage::getModel('catalog/category')
->getCollection()
->addAttributeToSelect('*')
->addIsActiveFilter()
->addLevelFilter(1)
->addOrderField('name');

4. Display Store Specific Categories

The following code will fetch all active store specific categories.

getStoreCategories($sorted=false, $asCollection=false, $toLoad=true)
$helper = Mage::helper('catalog/category');

// sorted by name, fetched as collection
$categoriesCollection = $helper->getStoreCategories('name', true, false);

// sorted by name, fetched as array
$categoriesArray = $helper->getStoreCategories('name', false, false);

5. Display Top level categories only in Magento

The following code will fetch all the Top level categories only

<?php $_helper = Mage::helper('catalog/category') ?>
<?php $_categories = $_helper->getStoreCategories() ?>
<?php if (count($_categories) > 0): ?>
<ul>
<?php foreach($_categories as $_category): ?>
<li>
<a href="<?php echo $_helper->getCategoryUrl($_category) ?>">
<?php echo $_category->getName() ?>
</a>
</li>
<?php endforeach; ?>
</ul>
<?php endif; ?>

6. Display Top Level Categories as well as ALL Subcategories in Magento

The following code will fetch all the Top Level Categories as well as ALL Subcategories

<?php $_helper = Mage::helper('catalog/category') ?>
<?php $_categories = $_helper->getStoreCategories() ?>
<?php $currentCategory = Mage::registry('current_category') ?>
<?php if (count($_categories) > 0): ?>
<ul>
<?php foreach($_categories as $_category): ?>
<li>
<a href="<?php echo $_helper->getCategoryUrl($_category) ?>">
<?php echo $_category->getName() ?> //Top Level Category Listing
</a>
<?php $_category = Mage::getModel('catalog/category')->load($_category->getId()) ?>
<?php $_subcategories = $_category->getChildrenCategories() ?>
<?php if (count($_subcategories) > 0): ?>
<ul>
<?php foreach($_subcategories as $_subcategory): ?>
<li>
<a href="<?php echo $_helper->getCategoryUrl($_subcategory) ?>"> //Sub Category Listing
<?php echo $_subcategory->getName() ?>
</a>
</li>
<?php endforeach; ?>
</ul>
<?php endif; ?>
</li>
<?php endforeach; ?>
</ul>
<?php endif; ?>

7. Display Subcategories only for the Current Top Category

The following code will fetch all Subcategories only for the Current Top Category

<?php $_currentCategory = Mage::register('current_category') ?>
<?php $_helper = Mage::helper('catalog/category') ?>
<?php $_categories = $_helper->getStoreCategories() ?>
<?php if (count($_categories) > 0): ?>
<ul>
<?php foreach($_categories as $_category): ?>
<li>
<a href="<?php echo $_helper->getCategoryUrl($_category) ?>" title="<?php echo $_category->getName() ?>">
<?php echo $_category->getName() ?>
</a>
<?php if ($_category->getId() == $_currentCategory->getId()): ?>
<?php $_subcategories = $_currentCategories->getChildrenCategories() ?>
<?php if (count($_subcategories) > 0): ?>
<ul>
<?php foreach($_subcategories as $_subcategory): ?>
<li>
<a href="<?php echo $_helper->getCategoryUrl($_subcategory) ?>" title="<?php echo $_subcategory->getName() ?>">
<?php echo $_subcategory->getName() ?>
</a>
</li>
<?php endforeach; ?>
</ul>
<?php endif; ?>
<?php endif; ?>
</li>
<?php endforeach; ?>
</ul>
<?php endif; ?>

Hope this will be helfull. Thanks