Auto-changing the “Stock Availability” from “Out of Stock” to “In Stock” on quantity change

Question

assume the product quantity is "0", once we edit the quantity to "1". again we have to change from

"out of stock" to " in stock" to buy in site

So I’ve been looking for a way to change the Stock Availability back to In Stock when the quantity field is greater than 0.

here someone posted solution : https://stackoverflow.com/questions/7168295/magento-auto-changing-the-stock-availability-from-out-of-stock-to-in-stock

we can use Magento event catalog_product_save_after. Create an observer method that does the following on event catalog_product_save_after.

can anyone please explain me in detail what and all needs to be done for this. means in which file which code we have to add ?

public function catalog_product_save_after($observer) {
    $product = $observer->getProduct();
    $stockData = $product->getStockData();

    if ( $product && $stockData['qty'] ) {
        $stock = Mage::getModel('cataloginventory/stock_item')->loadByProduct($product->getEntityId()); // Load the stock for this product
        $stock->setData('is_in_stock', 1); // Set the Product to InStock                               
        $stock->save(); // Save
    }
}

as Qaisar Satti said i am trying this :

app/etc/modules/Froggyline_HappyHour.xml

<?xml version="1.0"?>
<config>
  <modules>
    <Froggyline_HappyHour>
      <active>true</active>
      <codePool>community</codePool>
      <version>0.0.0</version>
    </Froggyline_HappyHour>
  </modules>
</config>

app/code/community/Froggyline/HappyHour/etc/config.xml

    <?xml version="1.0"?>
<config>
  <modules>
    <Froggyline_HappyHour>
      <version>0.0.0</version>
    </Froggyline_HappyHour>
  </modules>
  <adminhtml>  
        <events>

                <cataloginventory_stock_item_save_commit_after>
                    <observers>
                        <happyhour>
                            <type>model</type>
                            <class>happyhour/observer</class>
                            <method>product_save_after</method>
                        </happyhour>
                    </observers>
                </cataloginventory_stock_item_save_commit_after>
        </events>
    </adminhtml> 

</config> 

app/code/community/Froggyline/HappyHour/Model/Observer.php

 <?php
class Froggyline_HappyHour_Model_Observer {
public function product_save_after($observer) {
    $product = $observer->getProduct();
    $stockData = $product->getStockData();

    if ( $product && $stockData['qty'] ) {
        $stock = Mage::getModel('cataloginventory/stock_item')->loadByProduct($product->getEntityId()); // Load the stock for this product
        $stock->setData('is_in_stock', 1); // Set the Product to InStock                               
        $stock->save(); // Save
    }
}}

?>

Answer 1

Solution 1

Add this in config.xml

   <?xml version="1.0"?>
<config>
  <modules>
    <Froggyline_HappyHour>
      <version>0.0.0</version>
    </Froggyline_HappyHour>
  </modules>
  <adminhtml>  
        <events>
     //second event
               <catalog_product_save_after>
                    <observers>
                        <happyhour>
                            <type>model</type>
                            <class>happyhour/observer</class>
                            <method>product_save_after</method>
                        </happyhour>
                    </observers>
                </catalog_product_save_after>
        </events>
    </adminhtml> 

</config> 

app/code/community/Froggyline/HappyHour/Model/Observer.php

   <?php
class Froggyline_HappyHour_Model_Observer {
public function product_save_after($observer) {
    $product = $observer->getProduct();
    $stockData = $product->getStockData();

    if ( $product && $stockData['qty'] ) {
        $stock = Mage::getModel('cataloginventory/stock_item')->loadByProduct($product->getEntityId()); // Load the stock for this product use for 
        $stock->setData('is_in_stock', 1); // Set the Product to InStock                               
        $stock->save(); // Save use for 
    }
}
 }

Solution 2 (Not Tested, But Better Solution)

Add this in config.xml

   <?xml version="1.0"?>
<config>
  <modules>
    <Froggyline_HappyHour>
      <version>0.0.0</version>
    </Froggyline_HappyHour>
  </modules>
  <adminhtml>  
        <events>
     //second event
               <catalog_product_prepare_save>
                <observers>
                    <happyhour>
                        <type>model</type>
                        <class>happyhour/observer</class>
                        <method>product_prepare_save</method>
                    </happyhour>
                </observers>
            </catalog_product_prepare_save>
        </events>
    </adminhtml> 

</config> 

app/code/community/Froggyline/HappyHour/Model/Observer.php

   <?php
class Froggyline_HappyHour_Model_Observer {

public function product_prepare_save($observer) {
        $product = $observer->getProduct();
        $stockData = $product->getStockData();

        if ( $product && $stockData['qty'] ) {

            $stockData->setData('is_in_stock', 1); // Set the Product to InStock                               

        }
    }
 }

Answer 2

I write here only the main steps

1) write a custom module skeleton you can use several "module creators" I personally use this http://www.silksoftware.com/magento-module-creator/

You can set you company and module name and live all other options to NO to create a skeleton module

2) open etc/config and add you Model Name class, end declare the event observers you need

  <global>
    <models>
        <moduloname>
            <class>company_modulo_Model</class>
        </moduloname>
    </models>
    <events>
       < catalog_product_save_after>
        <observers>
            <moduloname>
                <class>moduloname/observer</class>
                <method>yourFunc</method>
            </moduloname>
        </observers>
    </catalog_product_save_after>

3) create Model/Observer.php and write yourFun inside

    <?php  
    class company_Modulo_Model_Observer
{

    public function yourFunc(Varien_Event_Observer $observer) {
    }
 }

For deeper details in the above steps there are tons of other resources, the above is only a sketch of what you have to do

hope it helps

Answer 3

In app/design/adminhtml/default/default/template/catalog/product/tab/inventory.phtml I have changed this:

<?php foreach($this->getStockOption()as $option):?>
<?php $_selected =($option['value']== $this->getFieldValue('is_in_stock'))?'selected="selected"':''?>
<option value="<?php echo $option['value']?>" <?php echo $_selected ?>>
<?php echo $option['label']?></option><?php endforeach;?>

To this:

<?php if(($this->getFieldValue('qty')*1)>0):?>
<option selected="selected"value="1">In Stock</option><?php else:?>
<option selected="selected"value="0">Out of Stock</option><?php endif;?>