Adding a Custom Column in the Admin Grid in Magento 1.9
One of the best things about working in magento is that if you are comfortable with an object oriented style, you start seeing patterns everywhere. If a new functionality calls for it, you can add a child class and with a little bit of magento-xml-config-magic, you can add virtually (well, concretely) anything new by replacing the existing class. Recently, one of the interesting things one of our clients asked us to do was to add an extra column in the orders grid in the magento admin.