Question

So I want this code to display the categories children and their children on my view.phtml page in app/frontend/default/default/catalog/category/

So when you see the category page you see ALL of the children from all the sub categories

Here is what I got, it is showing sub categories, but not their children.

    <?php
    $_category  = $this->getCurrentCategory(); 
    $collection = Mage::getModel('catalog/category')->getCategories($_category-       >entity_id);
    $helper     = Mage::helper('catalog/category');
    ?>

   <ul>
    <?foreach ($collection as $cat):?>
            <?php if($_category->getIsActive()):?>
            <?php 
                 $cur_category = Mage::getModel('catalog/category')->load($cat->getId());
                 $_img = $cur_category->getImageUrl();  
            ?>
            <li>
                            <a href="<?php echo $helper->getCategoryUrl($cat);?>">
                                 <img src="<?php echo $_img?>" title="$cat->getName()"/>
                                 <cite><?php echo $cat->getName();?></cite>
                            </a>
                    </li>
            <?php endif?>

<?php endforeach;?>

Answer 1

Please try to use following code.
Main idea is get main level category. For each category get children categories.

<?php
      /* Get the categories that are active for the store */
      $_main_categories=$this->getStoreCategories();

      /* Get the current category the user is in */
      $_current_category=$this->getCurrentCategory();

      /* Get the current category path */
      $_categorypath = $this->getCurrentCategoryPath();
?>

    <?php if ($_main_categories): ?>
        <div class="box normal-nav">
            <div class="box-top">
            </div>
            <div class="box-content">
                    <ul>
                        <?php
                            /* This bit cycles through the categories - setting the next one to current */
                            foreach ($_main_categories as $_main_category):
                                if($_main_category->getIsActive()):
                                    $cur_category=Mage::getModel('catalog/category')->load($_main_category->getId());
                                    $layer = Mage::getSingleton('catalog/layer');
                                    $layer->setCurrentCategory($cur_category);
                        ?>

                                    <li><a href="<?php echo $this->getCurrentCategory()->getUrl()?>"><?php echo $this->getCurrentCategory()->getName();?></a>

                                        <?php $_maincategorylisting=$this->getCurrentCategory()?>

                                        <?php $_categories=$this->getCurrentChildCategories()?>

                                        <?php if($_categories->count()): ?>
                                            <ul class="subcategory">
                                                <? foreach ($_categories as $_category):?>
                                                   <? if($_category->getIsActive()):
                                                          $cur_subcategory=Mage::getModel('catalog/category')->load($_category->getId());
                                                          $layer = Mage::getSingleton('catalog/layer');
                                                          $layer->setCurrentCategory($cur_subcategory);
                                                   ?>

                                                          <li><a href="<?php echo $this->getCategoryUrl($_category)?>"> <?php echo $_category->getName()?></a></li>
                                                   <? endif;?>

                                                 <?endforeach?>

                                            </ul>
                                            <?php $layer->setCurrentCategory($_current_category);  ?>

                                        <? endif; ?>
                                    </li>

                             <?php endif; ?>

                        <?php endforeach; ?>
                    </ul>
                </div>
                <div class="box-bottom">

                </div>
        </div>
    <?php endif;  ?>

Added later:

If apply fix for your code is look like following:

    <?php
        $_category  = $this->getCurrentCategory();
        $collection = Mage::getModel('catalog/category')->getCategories($_category->entity_id);
        $helper     = Mage::helper('catalog/category');
    ?>
   <ul>
    <?php foreach ($collection as $cat):?>
            <li>
                <a href="<?php echo $helper->getCategoryUrl($cat);?>">
                    <cite><?php echo $cat->getName();?></cite>
                </a>
                <?php $childLevel2Category = Mage::getModel('catalog/category')->getCategories($cat->entity_id); ?>
                <ul>
                    <?php foreach ($childLevel2Category as $catLevel2) { ?>
                        <li>
                            <a href="<?php echo $helper->getCategoryUrl($catLevel2);?>">
                                <cite><?php echo $catLevel2->getName();?></cite>
                            </a>
                        </li>
                    <?php } ?>
                </ul>
            </li>
<?php endforeach;?>
   </ul>

If you need more level (more sub-dir) rewrite this construction using recursive function.