Magento - Calculated Product Attribute (property) - magento

I would like to add a calculated attribute (property) to Products. It's value is to be calculated using a PHP function eg:
function CalculateCustomAttribute() {
...
//Do some calculations based on other Product attributes, date, etc
...
return $calculatedValue; // type float
}
This calculated attribute needs to be:
displayed in the Product page,
filterable through the "Layered Navigation", and
sortable in the "Product Listing".
Could this be done? And how?

What you want to do might be possible, but I am not sure that the approach you have described would be doable, I think it is too simplistic to work with the very complex Magento platform.
I had a similar project where the actual price of the products was constantly changing based on a few inputs and I was able to solve the problem fairly well, but it was definitely more complicated thank what you seem to be hoping for. I am not sure this scenario is helpful to you or not, but here it goes...
The basic idea was that I created new product attributes (eav attributes). These served as the inputs to determine what the price really should be. Note that in my case, these attributes were being updated fairly regularly by an outside process.
Then I created an observer on the "catalog_product_save_before" event that would simply do something like this:
//some calculations to get the $newPrice
$product->setPrice($newPrice);
So basically that will make it so that the price field will always be current whenever you save a product in the administrative screens.
Then also, since several of the attributes that were used as inputs were constantly changing (updated by an outside process), so we also had to add a magento cron job to run every so often, and it would recalculate the price for all the affected products with something like this...
//some calculations to get the $newPrice
$product->addAttributeUpdate("price", $newPrice, Mage::app()->getStore()->getStoreId());
So it all boils down to the fact that you should have the attribute saved in the db. And of course you need to find the specific spots of where to update that derived attribute. Maybe your requirements will vary slightly from what I have described, but it might get you on the right path at least.

Related

Updating Magento Inventory through Extension on simple and complex products

I am updating the Stock on Hand Inventory Qty on a Magento store through an extension that I have developed, using the following code:
Mage::getModel("cataloginventory/stock_item")
->loadByProduct($pid)
->setQty($qty)
->save();
Now, from my testing, this works fine, however I am a little concerned if this is having any negative affects on the different types of product that can be created in Magento (such as simple and complex products).
Is the above the correct way to update the SOH, and do I need to handle Complex products any differently? My gut feeling is that I don't need to do anything differently with complex products as they all end up deriving from a Simple product which has its own Stock on Hand?
Any advice appreciated
As long as you only update simples you'll be fine like this. Indeed all other non-virtual product types derive their stock from the simples.
You might even want to add
$stockItem = Mage::getModel("cataloginventory/stock_item")
->loadByProduct($pid)
->setQty($qty);
if ($stockItem->getCanBackInStock() && $stockItem->getQty() > $stockItem->getMinQty()) {
$stockItem->setIsInStock(true)
->setStockStatusChangedAutomaticallyFlag(true);
}
$stockItem->save();
See Mage_CatalogInventory_Model_Stock::backItemQty() to see how Magento adds stock.

Magento: how to get the price of a product with catalog rules applied

I'm developing a script (external to Magento, not a module) which aims to output a text list of all available products, their prices and some other attributes. However, catalog price rules don't seem to be applied to product prices. If I use any of the following:
$_product->getPrice()
$_product->getFinalPrice()
I get the normal price (without rules being applied).
If I use:
$_product->getSpecialPrice()
I get null unless the product actually has a special price inserted in the product itself (i.e. if special price is not related with catalog rules).
I also tried
Mage::getModel('catalogrule/rule')->calcProductPriceRule($product,$product->getPrice())
as suggested in the answer given by Fabian Blechschmidt, but interestingly it returns the normal price only if the product is affected by any catalog rule, returning null otherwise.
There was a similar question in StackOverflow and Magento Forums some time ago, but the provided answer (which is to insert the code bellow) doesn't work for me (returned prices remain the same).
Mage::app()->loadAreaPart(Mage_Core_Model_App_Area::AREA_FRONTEND,Mage_Core_Model_App_Area::PART_EVENTS);
Does anybody have an idea of how to achieve this?
I'm using Magento 1.6.2.0.
Thanks in advance.
Thanks to you, I found a new site:
http://www.catgento.com/magento-useful-functions-cheatsheet/
And they mentioned:
Mage::getModel('catalogrule/rule')->calcProductPriceRule($product,$product->getPrice())
HTH
As catalog price rules heavily depend on time, store and visiting customer, you need to set those parameters when you want to retrieve the product final price with it's price rules applied.
So, in your case, make sure that provided product is passed with the desired store and customer group id, which can be set as:
Mage::getModel('catalogrule/rule')->calcProductPriceRule($product->setStoreId('STORE_ID')->setCustomerGroupId('CUSTOMER_GROUP_ID'),$product->getPrice())
I discovered the problem. The discounted prices display Ok in the store frontend. The problem was that I was developing a script "external" to Magento (thus not a Magento module), something like:
<?php
set_time_limit(0);
ignore_user_abort();
error_reporting(E_ALL^E_NOTICE);
header("Content-Type: text/plain; charset=utf-8");
require_once "app/Mage.php";
// Get default store code
$default_store = Mage::app()->getStore();
...
For everything to work properly it seems that one must follow the proper Magento bootstrap, and develop everything as a module. My script was so simple that I thought it wouldn't be necessary to code a complete module. In other words, everything in Magento should really be a module.
Concluding, using the module approach, all the methods work as expected:
$_product->getPrice()
$_product->getFinalPrice()
$_product->getSpecialPrice()
Thank you all for your input.
This helped me in this issue: http://www.magentocommerce.com/boards/viewthread/176883/
. Jernej's solution seems plausible, but it does not handle rules that Overwrite other rules by using 'stop processing' and therefore can apply more than one rule.
$original_price = $_product->getPrice();
$store_id = 1; // Use the default store
$discounted_price = Mage::getResourceModel('catalogrule/rule')->getRulePrice(
Mage::app()->getLocale()->storeTimeStamp($store_id),
Mage::app()->getStore($store_id)->getWebsiteId(),
Mage::getSingleton('customer/session')->getCustomerGroupId(),
$_product->getId());
// if the product isn't discounted then default back to the original price
if ($discounted_price===false) {
$discounted_price=$original_price;
}

Virtuemart Coupon Plugin based on quantity not value

I've had a look at available Virtuemart plugins and I can't find anything close to what I am after. This is what I need.
Allow admin user to create coupon codes. An import feature would be nice as there will be thousands but I can handle this bit if needed anyway.
The admin user selects the number of products the customer is allowed for each coupon code.
When the customer uses the coupon code they are allowed to choose any product on the website up to the total amount of products issued to the coupon. Regardless of the products price.
Nice extra would be to allow free shipping with the coupon.
I've looked at the possibility of extending virtuemart and I think it would be possible. It would however require quite a lot of changes and if I can find something that is halfway there it would help me on my way.
Thanks in advance.
OK well time was running out and I didn't get an answer so I rolled my own. It was actually fairly painless. I can't release the code but I can give you a good idea of the steps and a direction to go in.
extend vm_ps_coupon and override the update, add and process methods. Add and update should only require a change to the array that is sent to the DB. See here for more info on extending classes
Alter the enum in the database to allow for quantity as well as total and percent.
Within your new update method handle the variation of quantity to do as you need.
In the update method you can also set a flag for free shipping in a session variable.
In templates/checkout edit list_shipping_methods.php. Simply check for the free shipping flag and load the free_shipping class. You can then call free_shipping->list_rates($vars);
extend vm_ps_checkout, override the add method, call the parent add method and then check the result so you can delete the session variable for the free shipping.
Finally you will need to make some changes in the HTML. Unfortunatly i could not find a way to override this easily and since its only two small changes to the markup i just went ahead and hacked the core. If anyone knows of another way that would be great? I did see something online about using a Joomla hook and a System plugin but I'd rather keep it reliant on Virtuemart only.
In administrator/components/com_virtuemart/html/ edit coupon.coupon_form.php to show the new quantity radio button.
Then edit coupon.coupon_list.php to display the correct values. Currently it will only display percent and total.
Hope this helps someone in the future. If you need some assistance then post on here and I'll be happy to help.

Magento - tracking who to give back to

We have a Magento multi-site that give a percentage back to a non-profit, and what we would like to do is to allow customers to select which non-profit or a group within that non-profit to receive the percentage.
Trying to keep it simple we thought allowing customers to enter a discount code named something like "GIVE BACK to {non-profit name}" (but no actual dollar amount subtracted from the purchase or maybe just a penny, I don't think you can have a 0 to a discount code), then internally we know to give the percentage back to that non-profit.
It just seems a little bit of an odd way of doing this, it would be better to have a drop down of the none-profits at the end, but we are not sure how to create that.
Does anyone have any suggestions, on an easy way of doing this?
Thanks in advance!
You could add an attribute to the quote/order model and then populate that with an appropriate value, populated at the cart level? It's the kind of think we've done for affiliate modules we've built in the past.
You'll need a custom controller to grab the value when the customer moves from the cart to the checkout, which means you'll also need to make the Cart -> Checkout step a form submission instead of a straight link.
Then, at the end of the month, you'll need to run a report on the collection with something along the lines of:
// I've added a * in the SELECT because I'm not sure of the attribute names off the top of my head :)
$collection = Mage::getModel('sales/order')->getCollection()
->addAttributeToSelect('*')
// Make sure the orders are in the correct date range
->addAttributeToFilter(...)
// Make sure the orders are in a valid state, e.g. processing, pending, complete, etc..
->addAttributeToFilter(...)
$donation_total = array();
foreach ($collection as $order) {
// You'll have to investigate the attribute values for these
$charity = $order->getData('charity_attribute_code');
$order_total = $order->getData('order_total_attribute_code');
if (!isset($donation_total[$charity])) {
$donation_total[$charity] = 0;
}
$donation_total[$charity] += $order_total;
}
print_r($donation_total);
You could make this more efficient with proper SUM()ing in the query.

how to add more simple products into configurable products using magento API

How can I simply add new simple products incrementally to configurable products?
or do I still need to retrieve the 2 original arrays of the pre-defined configurable product (getConfigurableAttributesData and getConfigurableProductsData) first, append the new arrays and set them again? Is it worked for my case just as the first-time creation?
And if the new simple product owns a new attribute / attribute options, do I also need to create /edit the attribute first before adding?
Thanks in advance!
The API as it stands does not have the functionality to do this.
Your options are:
Extend the API. (Hours of fun)
Do it with Magento methods in your own module or standalone code that includes Mage.php.
SQL script mixed in with your existing API code.
Buy someone's module - (Hope your German is good)
The approach you take also depends on your SKU naming scheme, if you have a simple BASECODE-SIZE-COLOUR type of scheme then the SQL option can work a treat, and in next to no time, but will be heavily scorned on by Magento evangelists.
That means you are probably going to have to write your own code. Here is a very useful site that should help get you started:
http://www.ayasoftware.com/
As well as being able to import configurables (by a variety of means including SQL) there are also snippets of code useful for updating superattribute price differentials. No readymade complete solution, but, you may need to roll your own anyway depending on your SKU naming scheme.
Whilst you are at it you may also want to write some code to find simple products that are not hooked up to anything when they should be, i,e. the ones with no visibility.

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