Mfrhtyj

I have loaded custom template before the product list in category list page.

this is my block file Vendor/Module/Block/Category.php

<?php 

namespace VendorModuleBlock;

class Category extends MagentoFrameworkViewElementTemplate{

protected $categoryFactory; 

protected $_storeManager;    

protected $_categoryCollectionFactory;

public function __construct(

    MagentoBackendBlockTemplateContext $context,

    MagentoCatalogModelCategoryFactory $categoryFactory,

    MagentoStoreModelStoreManagerInterface $storeManager,

    MagentoCatalogModelResourceModelCategoryCollectionFactory $categoryCollectionFactory

)

{    

    $this->categoryFactory = $categoryFactory;

    $this->_storeManager = $storeManager;

    $this->_categoryCollectionFactory = $categoryCollectionFactory;

    parent::__construct($context);

}



 public function getParentCategoryList(){       

     $categoryId = 3; 

     $category = $this->categoryFactory->create()->load($categoryId);       

     $childrenCategories = $category->getChildrenCategories();

     return $childrenCategories;

} 

 public function getChildCategoryList($categoryId){     

     $category = $this->categoryFactory->create()->load($categoryId);

     // Children  Categories

     $childrenCategories = $category->getChildrenCategories();

     return $childrenCategories;

  }

}

This is my template file view/frontend/template/category.phtml

 <?php 

    $parentCategories = $block->getParentCategoryList();

 ?>



  <div class="select-box">

   <div class="container">

    <div class="custom-dropdown">



       <select id="parent-cat" name="parent-cat"       



             onchange="getChildrenList(this.value)">    

             <option value ="">- Please Select -</option>

             <?php foreach($parentCategories as $parent){

                    $parentCatName = $parent->getName();

                    $parentCatUrl = $parent->getUrl();

                    $parentCatId = $parent->getId();

            ?>

                <option value="<?php echo $parentCatId; ?>"><?php echo 

            $parentCatName; ?></option>  

            <?php } ?>

        </select>

    </div> 



    <div class="custom-dropdown center-cus-drop">

        <select id="child-cat" name="child-cat" 

          onchange="getChildUrl(this.value)">    

            <option value ="">- Product category -</option>

        </select>

    </div> 



  </div>

</div>

  <script>  

    function getChildrenList(parentId) {

    if(parentId !=''){

        var customurl = "<?php echo $this- 

    >getUrl().'frontname/category/childcategory' ?>";

        jQuery.ajax({

             url: customurl,

             type: "POST",

             data : 'category_id='+parentId,

             dataType: 'json',

             success : function(result) {                

                var optionHtml; 

                optionHtml +='<option value="">-Product Category-</option>';                

                for(var option of result){

                  optionHtml +='<option value="'+option.url+'">'+option.name+'</option>';

                }

                jQuery('#child-cat').html(optionHtml);

             }

        }); 

   }

}



function getChildUrl(childUrl) {

    var url = childUrl; 

      if (url) { 

          window.location = url; // redirect

      }

      ///return false;

 } 



</script>

This is my controller file.

  use MagentoCatalogApiCategoryRepositoryInterface;

  use MagentoCatalogModelCategory;

  use MagentoFrameworkAppActionAction;

  use MagentoFrameworkAppActionContext;

  use MagentoFrameworkControllerResultJsonFactory;



 class Childcategory extends Action

 {

   protected $categoryRepository;

   protected $resultJsonFactory;



  public function __construct(Context $context, CategoryRepositoryInterface $categoryRepository, JsonFactory $jsonFactory)

{

    $this->categoryRepository = $categoryRepository;

    $this->resultJsonFactory = $jsonFactory;

    parent::__construct($context);

}



public function execute()

{

    $parentId = $this->getRequest()->getParam('category_id');     

    $category = $this->categoryRepository->get($parentId);

    $childrenData = ;



    foreach ($category->getChildrenCategories() as $childrenCategory) {

        $parent_category = $childrenCategory->getParentCategory();

        $childrenData = [

            'name' => $childrenCategory->getName(),

            'id' => $childrenCategory->getId(),

            'url'=> $childrenCategory->getUrl()

        ];

    }

    return $this->resultJsonFactory->create()->setData($childrenData);

   }

 }

I have done first part, once the parent category is selected, i am populating the next drop down with its child categories,

On selecting the second drop down, i am redirecting to the child category url.

In this case as url redirects, the selected options again disappears.

How can i make both the drop down are selected on redirecting. Please anyone help me on this issue. Thanks