check if reindexing is needed

Question

I need to easily and quickly check if indexing needs to be done. I have been looking around and have

$process = Mage::getSingleton('index/indexer')->getProcessById();

or

$process = Mage::getSingleton('index/indexer')->getProcessByCode(<process_code>);

Process Name ID Code 
Product Attributes 1 catalog_product_attribute 
Product Prices 2 catalog_product_price 
Catalog URL Rewrites 3 catalog_url 
Product Flat Data 4 catalog_product_flat 
Category Flat Data 5 catalog_category_flat 
Category Products 6 catalog_category_product 
Catalog Search Index 7 catalogsearch_stock 
Stock Status 8 cataloginventory_stock 
Tag Aggregation Data 9 tag_summary 

but I need to just quickly get the status. Is there a better way?

Answer 1

$process = Mage::getSingleton('index/indexer')->getProcessByCode('some_process_code');
if($process->getStatus()==Mage_Index_Model_Process::STATUS_REQUIRE_REINDEX){
    $process->reindexEverything();
}

By the way it has 3 statuses:

class Mage_Index_Model_Process extends Mage_Core_Model_Abstract
{
    const XML_PATH_INDEXER_DATA     = 'global/index/indexer';
    /**
     * Process statuses
     */
    const STATUS_RUNNING            = 'working';
    const STATUS_PENDING            = 'pending';
    const STATUS_REQUIRE_REINDEX    = 'require_reindex';

    /* class body here*/
}

Answer 2

"More to the point" can be achieved by filtering the processes collection by the status your looking for:

$indices = Mage::getSingleton('index/indexer')
        ->getProcessesCollection()
        ->addFieldToFilter('status', Mage_Index_Model_Process::STATUS_REQUIRE_REINDEX)
        ->getSize();
if($indices > 0) {
    // something needs to be re-indexed
}

In case you're looking for what is to be re-indexed you may want to get an array of relevant indices that require further processing:

$indices = Mage::getSingleton('index/indexer')
        ->getProcessesCollection()
        ->addFieldToFilter('status', 'require_reindex')
        ->getColumnValues('indexer_code');