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Internal Server Error 500 in Magento

lydh — Thu, 22 Oct 2009 04:14:27 +0000

Many of us who started experimenting with this interface and tried to place various values for Base URL, came to a dead end where Magento breaks. Usually, we get Internal Server Error 500 with each page load. The problem lies in the fact that we can no longer open the Magento administration to correct the error. What needs to be done in such a scenario?

One of our clients wrote me a message today:

I have put www.mydomain.com in a bad spot. I changed the base URL to {{base_URL}} and now im getting a 500 server error on both the front end and the admin panel. I have looked through the database and cannot find the right field to change this value back. Can you point me in the right direction?

The client went to System> Configuration> Web> Unsecure and placed an invalid value for Base URL field. Beware of this field. Unfortunately, Magento just updates it without any pre-warnings, but change of this specific value can cause Magento to crash.

Usually, we get an error that looks like this:

Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, webmaster@mysite.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

The client was on right path to find a solution. We need to open MySQL (usually via php MyAdmin) and find core_config_data table. Once there, manually update 2 rows:

config_id:3 web/unsecure/base_url => http://www.mydomain.com/
config_id:4 web/secure/base_url => https://www.mydomain.com/

Everything should work now. Hope this will help someone.

By Tomislav Bilic from Inchoo.net

Escape from EAV the Magento way

lydh — Wed, 21 Oct 2009 02:49:50 +0000

One of the differences between Magento eCommerce platform and lets say WordPress, when looked from developer point of view, is “avoid raw queries” approach. For a web application, Magento is massive system. His database, although not so massive but surely breathtaking with around 220 tables forces you to use “eye candy” EAV model to do even simple things.

For instance, if I were to tell you that I want you to retrieve 5 simple products from database that have price in the range of 200-600USD you would most likely spent 1-4 hours trying to work out the query. In the end you would be lucky if you even get the query that wont break on next Magento upgrade. Let me just remind you on some of the things you need to be careful in example above.

Your query would have to take in consideration the at least the following states: is my product visibility such that it can be seen in Catalog and search result, is my product enabled or disabled, is is out of stock, which website and store view has it been assigned, is it assigned to only one category and that category is disabled by some chance, does it have special price assigned, does it have promotion rules assigned, does it have content (descriptions) for multilingual site assigned.

All of those and more are questions that one has to take into consideration when doing raw database queries. It makes no sense to create query that fetches product and all its appropriate info (price, quantity, description…) if that product is disabled or assigned to category that is disabled. For instance, if you need “featured” product functionality and you manually create raw query that extracts one “featured” product to lets say home page. There you create nice block holding all the necessary info of the product with a link for lets say “Add to cart” or “View product”. Clicking one of those two link would give you most likely 404 if the product is disable or any other condition that enables the product to be shown is disabled.

So basically, raw SQL queries in Magento are a “no no” for most of the time. Too much work and you never know what they will change in future upgrades. Which brings me to this new trend of theirs which I like to call “Escape from EAV”.

EAV, also know as Entity Attribute Value was suppose to bee (or is) the next big thing in OOP. Anyhow, Magento and his way of EAV have two huge downfalls called LACK OF DOCUMENTATION and WHAT WILL THEY CHANGE IN NEXT UPGRADE. The other day I was working on a Magento shop that had 22 000 products. Almost all of them were simple products, just about 600 were grouped. The store was initially installed on Magento 1.2 version. Site was pretty much 95% complete from both graphic and development perspective. Anyhow, Magento version 1.3.1 was released and on client demand we decide to to upgrade. Important thing to keep in mind is that in version 1.3 Magento introduce “change in philosophy” concerning the EAV model.

Altough EAV sounds great (and really is great for most of the time), it can really slow things down with all those JOINS executed on database. So the Magento team decided to do a little flat tabling. Basically we now have massive data duplication in MySQL where data is taken from various tables and copied int one, the flat table. Flat tables were introduced for both Products and categories, in regards to various website and store views.

Basically Magento has the power to “on the fly” create tables and do the “magical” copying of data from various tables to the flat tables. I assume they were looking for a faster way to “assemble” Product objects in Magento which in turn should boost the speed of collection object i grew so found about. I can live with duplicated data in database, I mean I am not the one writing them down. But let me get back to real world scenario.

As I mentioned, store I have been working on had more than 20 000 products. Due to limitations of both MySQL and PHP failed to do Rebuilt that you can find in System > Configuration > Cache management. This failure caused corrupted data in database. This manifested with “empty” attributes (attributes not showing up in Layered navigation). I resolved the issue by “re saving” all of the 20 000 product with custom script I wrote. After that i noticed the data in flat tables got rebuild as well. This of course took several hours. Magento EAV model seems OK on paper, but with store that hold’s large number of products it simply does not work, at least not in way in which their collection objects are built. Changes introduced in form of flat tables in versions 1.3 should, to some extent, improve work with stores that have large numbers of products. However this improvement seems to come in form of “copy all data from scattered tables to single flat table”.

Solutions like these are nightmare when it comes to upgrading the store that already has large number of products in. System is expected to handle part of the job transparently but it failed, leaving the client with corrupted database.

So, a word of advice for upgrading an existing Magento store: NEVER do it on live site. Let professional developer transfer live site and database to his dev machine, or make a copy on some sub folder on live site. Magento’s extreme out of the box feature rich capabilities, open source philosophy and good marketing have made it extremely popular but be careful, free is such a a loose term.

I am really anxious to see the future path of EAV vs Flat model in Magento.

By Branko Ajzele from Inchoo.net

Magento block caching

lydh — Tue, 20 Oct 2009 01:48:05 +0000

Recently we were working on speeding up parts of client site which had usual problem of slow page loading caused by complicated configurable products. To solve the problem we were experimenting with extending core Magento caching capabilities.

Magento has built in predifined system of block output caching. Its block abstract has Zend_Cache caching capabilities that can be modified for your own needs. I’m showing here an example of caching whole product view block, however this is just a specific example of how things works, problems are different and requires different approach and solution.

I will start with some external reading and example itself. There is great article on Magento Wiki about this topic, along with category cache example on Magento forums.

With my Inchoo_BlockCaching.rar example module things should be little easier to understand.

Magento block caching depends of three things:
cache_lifetime => cache lifetime in seconds
cache_tags => cache type identifiers primarly used for deleting right cache at the right time
cache_key => cache identyfier

You can simply inject this data into construtor of any Magento block

protected function _construct()
{
$this->addData(array(
'cache_lifetime' => 3600,
'cache_tags'     => array(Mage_Catalog_Model_Product::CACHE_TAG),
'cache_key'      => $this->getProduct()->getId(),
));
}

or if you need some conditional approach like i did in this example define equivalent functions

public function getCacheKey(){}
public function getCacheLifetime(){}
public function getCacheTags(){}

By Ivan Weiler from Inchoo.net

Custom Transactional Emails

lydh — Mon, 19 Oct 2009 02:40:17 +0000

Since transactional emails are very important for the process of online shopping you need to have them set up just the you want them and the default templates just don’t cut it. You need your own logo, email data and custom verbiage to be consistent with the image of your company.

Here how it’s done :

1. Creating custom transactional e-mails via Admin

a) In the admin panel of your magento installation go to: System->Transactional Emails

You’ll be presented with a list of default emails. You’ll need to create a custom email so the only way to avoid writing our custom templates from scratch is to use the existing code of the template.
Hint: If you want to see the template before copying, first click on the “Preview” button on the right.

b) To create the new template click on the “Add new template” above the “Transactional Emails” list. This is the part where Magento helps you with the option to load a deafult template for you to customize. Nice feature indeed.

Once you have loaded the deafult template give it a unique name under the “Template name” input field by adding a prefix of your own but leaving the deafult name as well. Example: ” mysite :: New account “.

That way you can easily spot them in the long list of default and custom emails.

Afterwards you can easily customize the verbiage and styling within the “Template subject” and “Template content”.

The “Template content” is the body of the message that the user will recieve upon transaction so be sure to change the E-mail, name of the company etc. You’ll need to upload the logo of your company in the images folder of the skin you’re using.

Once you are done with editing, save the changes and repeat the process for the rest of the email templates.

2. Assigning the templates to different stores and storeviews

Assigning is the easiest part. Just go to the System > Configuration > Sales > Sales Emails and select the corresponding template minding the configuration scope.

After you’re done with setting your new templates save the configuration by clicking on the “Save config”.

That’s it. Wise thing to do now would be to check how the emails look when received so make a test purchase to verify everything is the way it should be.

By Željko Prša from Inchoo.net

Magento Connect

lydh — Mon, 19 Oct 2009 02:16:06 +0000

One of the first things that really confused me when i start using Magento is Magento connect. I just started learning things, so i was looking for some plugin examples. I visited Magento connect page with extensions and looked for download button, instead i found “Get extension key” one.

If i recall correctly their What is this? explanation wasn’t the same back then .. or i was just so terrified of Magento at start that i didn’t understand anything at that point I knew i need to paste that key somewhere, in something they called my Magento connect manager or Magento downloader, but i didn’t understand where it is.

1. Magento extensions

Visit Magento connect page. There are really some great extensions there and many of them are free.
Find extension that interest you, click “Get extension key”, agree with license agreement and get key. Pay attention to Stability description field (stable, alpha, beta).

Also read What is this? explanation and follow the instructions. Or just navigate to
http://www.yourmagentoshop.ext/downloader in your favorite browser.

If you click Settings tab of your connect manager you will see “Preferred State” option there. If you’re installing extension with different “stability” or you get something similar to

“Failed to download magento-community/xyz within preferred state “stable”, latest release is version 0.1, stability beta .. ”

you should change this option to appropriate one. You should of course be careful with alphas and betas and know what you’re doing.

If you are developer or just interested, ftp to downloader/pearlib/download after you install extension and you’ll find packed downloaded extensions there.

2. Magento upgrade

You can also automatically upgrade your Magento installation through connect manager with key

magento-core/Mage_All_Latest

Enjoy!

By Ivan Weiler from Inchoo.net

Simple product with custom options in grouped product in Magento

lydh — Sat, 17 Oct 2009 02:36:58 +0000

Does the title sound complicated? Grouped Products display several products on one page. For example – if you’re selling chef’s knives and you have the same knife in four sizes, you can make a grouped product to display all four sizes. Customers can select the size(s) they want and add to cart from this page. Another example would be a themed bedroom set – you can create a grouped product and sell the sheets, comforter, and pillow cases all from the same page.

Technically, we create a simple products and after that a grouped products. When we edit the grouped product, we will associate simple products to it.It works very fine, but some of you might have issue if a simple product has custom options. If that’s the case, and if costum options are set as required (default way), the simple product will not be associative to the grouped product. Let’s see what needs to be changed in that case.

On Magento site, there is a nice tutorial how to create a grouped product. Please read it first to become familiar with the process. If you don’t have to assign simple products with custom options to a grouped product, that tutorial will be enough.

In case you wish to have simple products with custom options listed, be sure you don’t set any of the custom options to be required.

By Tomislav Bilic from Inchoo.net

Get product review info (independent) of review page

lydh — Sat, 17 Oct 2009 02:27:44 +0000

Here at Inchoo, we are working on a private project, that should see daylight any time soon. One of the requirements we had is to show product review info on pages independent of product review page. Let’s say you wish to show review info on home page for some of the products. After few weeks with working with Magento, one learns how to use the model stuff directly from view files. Although this might not be the “right” way, it’s most definitely the fastest way (and I doubt most of your clients would prefer any other , especially if it’s some minor modification).

Here is a code to retrieve the product review info:

$storeId = Mage::app()->getStore()->getId();

$summaryData = Mage::getModel(’review/review_summary’)
->setStoreId($storeId)
->load($_product->getId());

/* @var $summaryData Mage_Review_Model_Review_Summary */

array(
['primary_id'] => 147
['entity_pk_value'] => 166
['entity_type'] => 1
['reviews_count'] => 1
['rating_summary'] => 80
['store_id'] => 1
)
*/

Just be sure to pass it the right product id number. Cheers…

By Branko Ajzele from Inchoo.net

Manual creation of Google Sitemap in Magento

lydh — Sat, 17 Oct 2009 02:15:19 +0000

Most of you probably know this, but let’s define what the sitemaps are. Sitemaps are a simple way for site creators to give search engines the information about pages on their site that are available for public. Basically, those are just 1 or more XML files that lists URLs for a site along with additional meta informatio about each URL (like last update, how often it changes, its importance relevant to other pages). With this in mind, search engines can be more clever while crawling the site. Click here see how sitemap of this site looks like.

You will hear the term Google Sitemap a lot, but XML Schema for the Sitemap protocol is not related only to Google at all. It can be used in many places, but the most important ones are Google Webmaster Tools and Yahoo! Site Explorer.

How do we create Google Sitemap in Magento?

1. Sitemap File Configuration

First we need to create sitemap file in Magento. This is basically pointer to tell Magento where to create sitemap file and how to name it. Log in to Magento Administration and go to:
Catalog -> Google Sitemap

Check to see if the sitemap file is already present. Lets assume we wish to create sitemap in the URL: http://www.yourstore.com/sitemap/sitemap.xml
To do it successfully,

FTP to the server
create sitemap folder
chmod the folder to 777

On some servers, previous steps will not be required, but it is better to create the file first so that Magento can edit it.

Let’s go to Magento administration now and click on “Add Sitemap” button. Just insert the default values.

After this step, we just told Magento where to create sitemap file. It is not yet created.

2. Configure Sitemap

Sitemap can be configured from the interface System -> Configuration -> Catalog->Google Sitemap. If you are not sure what does it all mean, check XML Tag definitions section from “Sitemaps XML format” document.

3. Create Sitemap Manually

Looks like Magento folks were thinking that sitemap should only be created by a cron job. Yes, it can be done that way also. Be sure to read Wiki article How to Set Up a Cron Job to get familiar with it. If you are looking for manual creation, quit your search for “Create Sitemap” button. You will not find it. But there is a workaround. You can enter manual URL to execute sitemap creation:

http://www.yourstore.com/index.php/admin/sitemap/generate/sitemap_id/[ID of Sitemap from step 1]

Of course, replace the content with square brackets with actual Sitemap ID.

By Tomislav Bilic from Inchoo.net

Designer’s Guide to Magento PDF download

lydh — Fri, 16 Oct 2009 02:36:18 +0000

After many developed CRE Loaded’s online stores and watching Magento development progress for quite some time, I decided it was time to use Magento with my next client. My starting point for development was official Designer’s guide. I’m the type of guy who likes to have documents nice&clean, so I tried to print it but print was a mess. That’s when I decided to create PDF of the official documentation for easy print. This is probably the best starting tutorial for creating a fresh new Magento template.
Download Designer’s Guide to Magento PDF

I plan to write a short related tutorials in the days of 1st Magento development project, so I invite you to subscribe to RSS if you wish to be posted.

By Tomislav Bilic from Inchoo.net

Magento, products on sale

lydh — Fri, 16 Oct 2009 02:17:07 +0000

Most of you probably know this, but here’s a little code snippet for every Magento beginner that needs page with products on sale listing.
So, easiest way to accomplish that is to follow these steps…

1) Make CMS page called “Products on sale”, or whatever you wanna call it…
2) Put this code:

{{block type="core/template" template="callouts/products_on_sale.phtml"}}

in CMS page you created
3) Make app/design/frontend/default/YOUR_THEME/template/callouts/products_on_sale.phtml
4) Put this code in products_on_sale.phtml

< ?php
$product    = Mage::getModel('catalog/product');
$collection = $product->getCollection();

foreach ($collection as $product)
{
$result[] = $product->getId();
}

$j = 0;
$product_ = array();
foreach ($result as $_product_id)
{
$in_stock = 0;

$_product = new Mage_Catalog_Model_Product();
$_product->load($_product_id);

#var_dump(get_class_methods(get_class($_product)));exit();
$time = time();
if(strtotime($_product->getSpecialFromDate()) < time() &amp;amp;amp;amp;amp;amp;&amp;amp;amp;amp;amp;amp; strtotime($_product->getSpecialToDate()) > time()) {
$product_[$j]['price'] = $_product->getPrice();
$product_[$j]['special_price'] = $_product->getSpecialPrice();
$product_[$j]['name'] = $_product->getName();
$product_[$j]['image'] = $_product->getSmallImageUrl();
$product_[$j]['url'] = $_product->getProductUrl();

$in_stock = $_product->isInStock();
if($in_stock) {
$in_stock = 'In Stock';
}else {
$in_stock = 'Out of Stock';
}

$product_[$j]['in_stock'] = $in_stock;

$j ++;
}
}

if(empty($product_)) {
echo $this->__('There is no product on sale');
}

foreach($product_ as $item)
{
?>


" alt="< ?php echo $item['name'];?>" />

< ?php echo $item['name'];?>

< ?php echo $item['price'];?>
< ?php echo $item['special_price'];?>
< ?php echo $item['in_stock'];?>


< ?php
}
?>

Style it at will
Enjoy!

P.S. Of course you need to add some products on sale
itemsonsale

By Tomas Novoselic from Inchoo.net