[php] Magento - Retrieve products with a specific attribute value

In my block code I am trying to programmatically retrieve a list of products that have a attribute with a specific value.

Alternately if that is not possible how would one retrieve all products then filter them to just list the products with a specific attribute?

How would I perform a search using standard boolean filters AND or OR to match a subset of my products?

create attribute name is "price_screen_tab_name". and access using this simple formula.

<?php $_product = $this->getProduct(); ?>
<?php echo $_product->getData('price_screen_tab_name');?>

This is a follow up to my original question to help out others with the same problem. If you need to filter by an attribute, rather than manually looking up the id you can use the following code to retrieve all the id, value pairs for an attribute. The data is returned as an array with the attribute name as the key.

function getAttributeOptions($attributeName) {
    $product = Mage::getModel('catalog/product');
    $collection = Mage::getResourceModel('eav/entity_attribute_collection')
              ->setEntityTypeFilter($product->getResource()->getTypeId())
              ->addFieldToFilter('attribute_code', $attributeName);

    $_attribute = $collection->getFirstItem()->setEntity($product->getResource());
    $attribute_options  = $_attribute->getSource()->getAllOptions(false);
    foreach($attribute_options as $val) {
        $attrList[$val['label']] = $val['value'];
    }   

    return $attrList;
}

Here is a function you can use to get products by their attribute set id. Retrieved using the previous function.

function getProductsByAttributeSetId($attributeSetId) {
   $products = Mage::getModel('catalog/product')->getCollection();
   $products->addAttributeToFilter('attribute_set_id',$attributeSetId);

   $products->addAttributeToSelect('*');

   $products->load();
   foreach($products as $val) {
     $productsArray[] = $val->getData();
  }

  return $productsArray;
}

To Get TEXT attributes added from admin to front end on product listing page.

Thanks Anita Mourya

I have found there is two methods. Let say product attribute called "na_author" is added from backend as text field.

METHOD 1

on list.phtml

<?php $i=0; foreach ($_productCollection as $_product): ?>

FOR EACH PRODUCT LOAD BY SKU AND GET ATTRIBUTE INSIDE FOREACH

<?php
$product = Mage::getModel('catalog/product')->loadByAttribute('sku',$_product->getSku());
$author = $product['na_author'];
?>

<?php
if($author!=""){echo "<br /><span class='home_book_author'>By ".$author ."</span>";} else{echo "";}
?>

METHOD 2

Mage/Catalog/Block/Product/List.phtml OVER RIDE and set in 'local folder'

i.e. Copy From

Mage/Catalog/Block/Product/List.phtml

and PASTE TO

app/code/local/Mage/Catalog/Block/Product/List.phtml

change the function by adding 2 lines shown in bold below.

protected function _getProductCollection()
{
       if (is_null($this->_productCollection)) {
           $layer = Mage::getSingleton('catalog/layer');
           /* @var $layer Mage_Catalog_Model_Layer */
           if ($this->getShowRootCategory()) {
               $this->setCategoryId(Mage::app()->getStore()->getRootCategoryId());
           }

           // if this is a product view page
           if (Mage::registry('product')) {
               // get collection of categories this product is associated with
               $categories = Mage::registry('product')->getCategoryCollection()
                   ->setPage(1, 1)
                   ->load();
               // if the product is associated with any category
               if ($categories->count()) {
                   // show products from this category
                   $this->setCategoryId(current($categories->getIterator()));
               }
           }

           $origCategory = null;
           if ($this->getCategoryId()) {
               $category = Mage::getModel('catalog/category')->load($this->getCategoryId());

               if ($category->getId()) {
                   $origCategory = $layer->getCurrentCategory();
                   $layer->setCurrentCategory($category);
               }
           }
           $this->_productCollection = $layer->getProductCollection();

           $this->prepareSortableFieldsByCategory($layer->getCurrentCategory());

           if ($origCategory) {
               $layer->setCurrentCategory($origCategory);
           }
       }
       **//CMI-PK added na_author to filter on product listing page//
       $this->_productCollection->addAttributeToSelect('na_author');**
       return $this->_productCollection;

}

and you will be happy to see it....!!

I have added line

$this->_productCollection->addAttributeToSelect('releasedate');

in

app/code/core/Mage/Catalog/Block/Product/List.php on line 95

in function _getProductCollection()

and then call it in

app/design/frontend/default/hellopress/template/catalog/product/list.phtml

By writing code

<div><?php echo $this->__('Release Date: %s', $this->dateFormat($_product->getReleasedate())) ?>
</div>

Now it is working in Magento 1.4.x

$attribute = Mage::getModel('eav/entity_attribute')
                ->loadByCode('catalog_product', 'manufacturer');

$valuesCollection = Mage::getResourceModel('eav/entity_attribute_option_collection')
            ->setAttributeFilter($attribute->getData('attribute_id'))
            ->setStoreFilter(0, false);

$preparedManufacturers = array();            
foreach($valuesCollection as $value) {
    $preparedManufacturers[$value->getOptionId()] = $value->getValue();
}   


if (count($preparedManufacturers)) {
    echo "<h2>Manufacturers</h2><ul>";
    foreach($preparedManufacturers as $optionId => $value) {
        $products = Mage::getModel('catalog/product')->getCollection();
        $products->addAttributeToSelect('manufacturer');
        $products->addFieldToFilter(array(
            array('attribute'=>'manufacturer', 'eq'=> $optionId,          
        ));

        echo "<li>" . $value . " - (" . $optionId . ") - (Products: ".count($products).")</li>";
    }
    echo "</ul>";
}