How to load category tree with category image

Question

I need load category image for the category tree. Currently I found a method to load category tree. But its not showing image of the category.

    public function getCategoryTree()
    {
        $model = Mage::getModel('catalog/category_api');
        $treeData = $model->tree();
        return $this->_sendJsonRespond('success', $treeData, null, null);
    }

Answer 1

You need to overwrite the tree and_nodeToArray functions of Mage_Catalog_Model_Category_Api :

/**
 * Retrieve category tree
 *
 * @param int $parent
 * @param string|int $store
 * @return array
 */
public function tree($parentId = null, $store = null)
{
    if (is_null($parentId) && !is_null($store)) {
        $parentId = Mage::app()->getStore($this->_getStoreId($store))->getRootCategoryId();
    } elseif (is_null($parentId)) {
        $parentId = 1;
    }

    /* @var $tree Mage_Catalog_Model_Resource_Eav_Mysql4_Category_Tree */
    $tree = Mage::getResourceSingleton('catalog/category_tree')
        ->load();

    $root = $tree->getNodeById($parentId);

    if($root && $root->getId() == 1) {
        $root->setName(Mage::helper('catalog')->__('Root'));
    }

    $collection = Mage::getModel('catalog/category')->getCollection()
        ->setStoreId($this->_getStoreId($store))
        ->addAttributeToSelect('name')
        ->addAttributeToSelect('is_active')
        ->addAttributeToSelect('image');

    $tree->addCollectionData($collection, true);

    return $this->_nodeToArray($root);
}

/**
 * Convert node to array
 *
 * @param Varien_Data_Tree_Node $node
 * @return array
 */
protected function _nodeToArray(Varien_Data_Tree_Node $node)
{
    // Only basic category data
    $result = array();
    $result['category_id'] = $node->getId();
    $result['parent_id']   = $node->getParentId();
    $result['name']        = $node->getName();
    $result['is_active']   = $node->getIsActive();
    $result['position']    = $node->getPosition();
    $result['level']       = $node->getLevel();
    $result['image']       = $node->getImage();
    $result['children']    = array();

    foreach ($node->getChildren() as $child) {
        $result['children'][] = $this->_nodeToArray($child);
    }

    return $result;
}

Following your needs, I think that retrieving the collection of categories and formating it to your needs would be more advised.