how to apply catalog price rules in magento by observer?

Question

i need to create price rule by programmatically with help of Observer

and i want to know that which event call for this

Answer 1

you can do this by event checkout_cart_product_add_after:

You need create config.xml for like below:

 <events>
          <checkout_cart_product_add_after>
              <observers>
                 <create_own_catalog_price_rules>
                    <type>singleton</type>
                    <class>yourmodel/observer</class>
                    <method>updatePrice</method>
                 </create_own_catalog_price_rules>
             </observers>
          </create_own_catalog_price_rules>
      </events>

And Observer.php code of create catalog price:

public function updatePrice( Varien_Event_Observer $obs ) 
 {
    $quote = $obs->getEvent()->getQuote();
        $item = $obs->getQuoteItem();
        $product_id=$item->getProduct_id();
        $_product=Mage::getModel('catalog/product')->load($product_id);

    $name = "My Catalog Price Rule"; // name of Catalog Price Rule
    $websiteId = 1;
    $customerGroupId = 2;
    $actionType = 'to_fixed'; // discount to fixed amount
    //(other options are: by_fixed, by_percent, to_percent)
    $discount = 20; // discount amount
    $sku = $_product->getSku(); // product sku

    $catalogPriceRule = Mage::getModel('catalogrule/rule');
    $catalogPriceRule->setName($name)
    ->setDescription('')
    ->setIsActive(1)
    ->setWebsiteIds(array($websiteId))
    ->setCustomerGroupIds(array($customerGroupId))
    ->setFromDate('')
    ->setToDate('')
    ->setSortOrder('')
    ->setSimpleAction($actionType)
    ->setDiscountAmount($discount)
    ->setStopRulesProcessing(0);
    $skuCondition = Mage::getModel('catalogrule/rule_condition_product')
    ->setType('catalogrule/rule_condition_product')
    ->setAttribute('sku')
    ->setOperator('==')
    ->setValue($sku);
    try {   
    $catalogPriceRule->getConditions()->addCondition($skuCondition);
    $catalogPriceRule->save();  
    $catalogPriceRule->applyAll();  
    } catch (Exception $e) {
    Mage::getSingleton('core/session')->addError(Mage::helper('catalog')->__($e->getMessage()));
    return;
    } 
  }