Blog - Page 4 of 14 - schmengler-se.de

5. December 201613. January 2020

PDF Generation in Magento 2

The Magento core methods to generate PDF files are rather unflexible. An alternative are tools that convert HTML to PDF.

In our current Magento 2 project, which we (integer_net) develop together with Stämpfli AG, there is a requirement to dynamically create a PDF catalog based on selected products, which has almost the same layout as the product lists in the shop. So, generating this PDF based on HTML suggested itself.

In this article I present our solution, which integrates wkhtmltopdf with the Magento layout. At the end you will find a link to the base module on Github.

Continue reading “PDF Generation in Magento 2”

10. October 201613. January 2020

The week on StackExchange #40/2016

Since the last “Weeks on StackExchange” post got quite long, I’ll get back to the weekly schedule:

Hot Magento 2 answers

I found an elegant solution to my own recent question, with DI configuration only: Force products collection to use EAV instead of flat table (with personal upvote from Ivan Chepurny, so it can’t be too bad)
Dependency Injection with dynamic constructor values is another example for the power of Magento’s DI configuration, here in combination with external libraries.
A general question about module architecture: Best practice for location of a class
In Magento 2 Layout Events: controller_action_layout_render_before vs. layout_render_before I ponder about how to make dynamic changes to the layout. The conclusion is not to use these events at all.
Is Magento compatible with PHP 7.1? Probably, but composer complains: Magento 2.1.1 not compatibile with PHP 7.1.0

Open questions

(Magento 2) I am trying to make a RequireJS override dependent on a backend configuration: Conditional RequireJS configuration
(Magento 1) Geo IP based store view selection with Varnish – has been answered but I’ve yet to try it out to get to a full solution.

5. October 201613. January 2020

5 Minute Tips: Form Usability

Learning coffee break! Today some tipps on “form usability”, a topic that even backend developers should not leave alone.

The final, one and only way to validate email addresses:

And for form validation: check if there is an “@”. Nothing more, nothing less. If you want to know why, read: The 100% correct way to validate email addresses.
But in one point I have to disagree:
Continue reading “5 Minute Tips: Form Usability”

3. October 201613. January 2020

The weeks on StackExchange #37-39/2016

Here we go again, a summary of interesting posts from the last weeks:

Magento 2 CLI

Use the Magento 2 profiler in CLI
TL;DR: with this workaround, you can activate the profiler in CLI scripts:
```
HTTP_ACCEPT="text/html" MAGE_PROFILER=csvfile bin/magento
```
How do we tell CLI scripts that our document root is pub? MAGE_DIRS bootstrap parameters in CLI – no answer yet, I fear this is not possible as of Magento 2.1

Magento 2 Extension Development

I probably shouldn’t tell anyone, but there is a way to replace any core class with this little composer trick: How to override a zend class
How to deploy public PHP files in Magento 2 extension? unanswered, +100 bounty
Dependency Injection with dynamic constructor values – how would you pass constructor arguments to dependencies?
Reasons to use the layout when instantiating blocks programmatically: Dynamically created blocks: layout->createBlock() or blockFactory->create()?
This is more a rant than a question, it seems like without core hacks it is not possible as of Magento 2.1: Get frontend category URL in admin area with correct base URL
Force products collection to use EAV instead of flat table, still has +100 bounty

Magento 2 Translation

How to translate core Magento modules and create a CSV translation file per module? – short answer: you don’t.

Magento Product Import

Why you shouldn’t use HTML encoded characters everywhere: How to import product name with ™ and ® symbol?

Magento 1 Best Practices

What does Varien_Object_Cache do and should you use it? Magento 1: using Mage::objects() to cache models
A little explanation of the relation between cron.sh and cron.php: Is adding “$isShellDisabled = true; ” in “cron.php” recommended?

Magento 1 Tipps

How to add a missing feature: ACL for the tabs on the order view page: set acl permission for tabs in sales order view
How to purge (delete) credit card numbers stored on Magento 1.9.1.0?

PHPUnit

Test output to php://stdout with PHPUnit

27. September 201613. January 2020

Isolating Domain Logic in Magento Customizations

Lately I’ve been advocating decoupling business logic from the framework (i.e. Magento) a lot.

This has multiple advantages:

Benefit from test driven development (TDD) without having to mock a bunch of core classes.
Possible reuse in different applications (for example Magento 1 and Magento 2)
Having separated bounded contexts helps to view parts of the domain isolated and without distraction.

Even in chirurgic modifications that we often have to do in Magento projects, it is worth identifying the actual logic and extracting it from the actual Magento classes.

Let me demonstrate it with a real-world example:

Stop using Helpers

“Helpers” are often used as convenient collection of functions. They are also a sign of bad design, and I want you to stop writing them. I’ll quote myself

In general, having classes named “Helper”, “Util” or similar just says “I have some functions that I don’t know where to put” and don’t make much sense as a class.

It’s not very object oriented. Not at all to be frank. The idea of object oriented programming is that there are objects that send each others messages. They have an active role in the system and are not just containers for data and code, which would be a very procedural way to see them.

So what would be the role of a helper? A butler maybe, that does not act on its own and will do anything you tell him. But to do that, he needs access to your whole household, your bank account and your car.

Continue reading “Stop using Helpers”

17. September 201613. January 2020

Memoize Method Calls in PHP with Cache Decorators

A “memoized” function is a function that only calculates the return value for each combination of arguments once and returns the previously calculated value if the function is called a second time with the same arguments.

In PHP, I often see this implemented with code like this:

class ProductRepository implements ProductRepositoryInterface
{
    private $products = [];
    public function product($id)
    {
        if (! isset($this->products[$id])) {
            $this->products[$id] = $this->load($id);
        }
        return $this->products[$id];
    }

    private function load($id) { ... }
}

Continue reading “Memoize Method Calls in PHP with Cache Decorators”

13. September 201613. January 2020

The week on StackExchange #36/2016

And again some new posts from Magento StackExchange that I’d like to highlight:

Magento 2

This is Session Configuration 101, but I found it interesting that Magento 2.1 has a hard coded value for the admin area: Logout customer when the browser is closed
How to use database transactions in Magento 2: Magento 2 – Database transaction for multiple model / resource model objects?
Another practical example for increment models, now in Magento 2: Add Dynamic Order Number Prefix [mm-yy-ordernumber]
A step on my journey to understand Magento 2.1 search engine adapters: Does layered navigation always have to use the configured search engine?
And a nasty little bug: “Asymmetric transaction rollback error” in integration test

Magento 1

Raphael from DigitalPianism came up with this question: Magento 1: how to make an extension EE compatible?. I started to answer it with a few bullet points but it could do with some more attention.

8. September 201613. January 2020

PHP: Using class_alias to maintain BC while moving/renaming classes

Sometimes you want to rename a class or move it to a different namespace. But as soon as it is used anywhere outside the package, this is breaking backwards compatibility and should not be done lightheartedly.

Luckily there is a way in PHP to have both, the old class and the new class, while deprecating the old one: class_alias().

How to use class_alias() without messing up class autoloading

Let’s say, the old class is OldClass and we want to rename it to NewClass.

First, we rename the class and move it from OldClass.php to a new file NewClass.php.
Continue reading “PHP: Using class_alias to maintain BC while moving/renaming classes”

7. September 201613. January 2020

The week on StackExchange #35/2016

I’m a bit late but I was quite active on the Magento StackExchange recently, so here are the best posts from last week!

Magento 1 answers

Maarten Wolfsen found a nice trick to add header elements like CSS files at the end for all pages: CSS file is loaded too early
Loading children of a category including disabled categories: Get Disabled Category Collection (Hint: you cannot use getChildren() for this)
A practical example for increment models (order numbers should be incremented by 4 each time): How to set order increment id iterator in magento 1?
Canonical answer for transactional emails: How to send mail from custom module?
Canonical answer for controller overrides: Magento 1 : how to override/rewrite a core controller class?