How I learned to stop worrying and love 3rd party modules for Magento

It’s just another day at the office. “Coffee tastes best on a Friday morning”, you think to yourself while reading emails from the previous day. Couple of guys are shouting in the back, and you’re shushing them angrily. With noise slowly diminishing, you find yourself checking an email with a request for custom change on one of your Magento stores. “Guys, we’ve got work to do. WeHeart3rdPartyModules Ltd. just requested a custom change on one of their stores. Who is willing to take on this one?”. Silence takes over the room. The only sound you hear is a fan from your colleagues PC (no need to ask why, Magento 2 is deploying static content). It seems like you’re in this alone. “Damn, I was hoping for a slow Friday”.

While PHPStorm is loading up, you’re reading the requirements:

Hi guys,

we would like to add a new column to our sales orders grid. We understand we have 20 of them already, but we really need this one – coupon description. Can you do this for us?


“You mean rule description, not coupon, noob!”
, a smirk appears on your face. “I’ve done this a couple of times already. Also, I think we have an article written about this exact problem”.

Using your google-fu, an article pops up on the screen: How to extend Magento Order Grid? says the title. “Just what I need. This will be a piece of cake”.

IDE is finally loaded, and you’re rushing to get this done as fast as possible. “app, code, local, Inchoo” – your mind shouts – “you’ve done this a million times before” – but then you stop, and dark cloud just hangs over you. “Now I remember why there were no volunteers. This project has over a hundred 3rd party modules in local pool alone”. Not only your Friday is ruined, but the entire weekend does not look promising either.

“Well, let’s dig in, then.” Your train of though is something along the lines: “they have over 100 modules.. email mentions some earlier changes on sales order grid (having 20 columns already).. there must be a 3rd party module enabling them, or.. have we implemented this change already?”. You jump to Inchoo_WeHeart module’s config.xml and see no rewrites on 'sales_order_grid' block. It must be 3rd party then. Lovely.

Fortunately, your IDE is good in identifying class hierarchy, and in just a couple of clicks you find the class rewrite, and 3rd party module responsible (actually several of them, but two are disabled):  Amasty extended order grid. This should be fun. Module allows us to select columns to add to “Sales > Orders” grid. Adrenaline spikes up – “what if the column we need can be added via admin? That would be so great”. You check system.xml and adminhtml.xml, run to the admin and start looking for columns. “Of course it’s not possible, it was too good to be true”.

You’ve been in this situation before, and you do the usual routine: start randomly opening 3rd party module’s classes hoping to find something so obvious that would allow you to finish this as fast as possible. Of course, you fail. Looks like a more systematic approach is needed after all. You’re checking config.xml, opening up observers, helpers, and many other classes, tracing the code. Finally you find it. It’s so obvious now.

Now, off to coupon description field. You go through Magento database, and find that coupon description is located in 'salesrule_coupon' table, but there is no description. Description is in another table – 'salesrule'. Looks like we’ll need 2 SQL joins for this. “It’s just a few lines”, a voice in your head says, “no one will notice it. And it’s not a core code, right?”. After a short struggle, you resist the temptation and decide not to change the module’s code directly (sell your soul for a quick fix).

Copying the code to local pool (if the module is in community) is also an option, but we can, and should, do better than that. Is class rewrite good enough? In most situations, yes, and this is one of those situations too. You quickly whip up a rewrite: “I can do this in my sleep”, you think to yourself, but somehow manage to spend 45 minutes on getting it to work (damn XML typo).

class Inchoo_WeHeart_Helper_Ogrid_Columns extends Amasty_Ogrid_Helper_Columns
    function prepareOrderCollectionJoins(&$collection, $orderItemsColumns = array()){
        parent::prepareOrderCollectionJoins($collection, $orderItemsColumns);
                'salesrule_coupon' => $collection->getTable('salesrule/coupon')
            'order.coupon_code = salesrule_coupon.code',
            array('salesrule_coupon.rule_id as coupon_rule_id')
                'salesrule_rule' => $collection->getTable('salesrule/rule')
            'salesrule_rule.rule_id = salesrule_coupon.rule_id',
            array('salesrule_rule.description as coupon_description')
    function getDefaultFields(){
        if (!$this->_defaultField){
            $this->_defaultField = array_merge(parent::getDefaultFields(), array(
                'discount_description' => array(
                    'header' => Mage::helper('sales')->__('Discount Description'),
                    'index' => 'coupon_description',
                    'filter_index' => 'salesrule_rule.description'
        return $this->_defaultField;

You look satisfied with the solution. Module has been changed, but in an unobtrusive way. Original logic has been kept, and new functionality added. With a few keystrokes, code is committed to a feature branch, and pushed to dev server. You test it there once more, and it looks like it’s working. Response message is sent:

“Hi WeHeart”, (no need to call them by their full name, they’re used to it), “changes have been made and pushed to dev server for you to test. Regards, Inchoo.

You close down the browser, and check the time: “Oh, looks like it’s time for my break”.

About Luka Rajcevic

Backend Developer

Big Tolkien and LOTR fan who plays guitar for his pleasure and relaxes while listening to jazz, blues or classical music.

Read more posts by Luka / Visit Luka's profile


  1. Hi! Luka Rajcevic your blog is very informative as you have mentioned how to learn 3rd party module for magneto, how to learn it and how it can provide help to enhance e-commerce platform.

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