magento how to get Json Config by product id - magento

Question

I am in need to get the Json Config by product id or sku in the product listing page for a particular category.
I can see that getJsonConfig is decalred in Product options block where only one particular product is showing thats why it can show Json Config without saying the product id. But I am in product list page.
Is there any way to get it like below?
$this->getJsonConfig($productId);

Answer 1

$this->getJsonConfig()
The method is part of
class Mage_Catalog_Block_Product_View
and it calls
/* #var $product Mage_Catalog_Model_Product */
$product = $this->getProduct();
public function getProduct()
{
if (!Mage::registry('product') && $this->getProductId()) {
$product = Mage::getModel('catalog/product')->load($this->getProductId());
Mage::register('product', $product);
}
return Mage::registry('product');
}
So to use it ( in any other page ) you have to set product in the block instance as below :
Mage::register('product', $_product); // add the product object in the registry
$block = Mage::getBlockSingleton('Mage_Catalog_Block_Product_View'); // Instantiate the product view block
echo $block->getJsonConfig();

Answer 2

I found a simple solution for configurable product view page.
Hope that will help.
if ($_product->isConfigurable())
{ $block1 = Mage::app()->getLayout()->createBlock('catalog/product_view');
$block1->setProduct($_product);
$configPrice = $block1->getJsonConfig(); //var_dump( $config = $block->getJsonConfig`enter code here`() );
$block2 = Mage::app()->getLayout()->createBlock('catalog/product_view_type_configurable');
$block2->setProduct($_product);
$config = $block2->getJsonConfig();
}
<?php if ($_product->isConfigurable()): ?>
<script type="text/javascript">
var optionsPrice = new Product.OptionsPrice(<?php echo $configPrice ?>);
</script>
<script type="text/javascript">
var spConfig = new Product.Config(<?php echo $config ?>);
</script>
<?php endif; ?>