Customising PDF invoices

[Avanor]

I'm migrating from Magento 1 to Magento 2, and it appears that my customised PDF invoices haven't come across.

I know how to use the Zend PHP framework - but I am not sure how to go about it.

In Magento 1, I copied the files in the Sales/Model/Order/PDF folder into app/code/local

rather than override the core code. Does Magento 2 work in the same way?

I was hoping not to just amend 

vendor/magento/module-sales/Model/Order/Pdf/Items/Invoice/DefaultInvoice.php. Is there a way to keep the original files the same (so that updates will still work), while still being able to have 'my' version too?

[Damian Culotta]

Hi @Avanor,

In Magento 2 we have a new concept: plugins

Also, you can use preferences to override some core (or another module) class.

The code pools don't work on M2. You should create a module and use a plugin or a preference to modify the vendor/magento/module-sales/Model/Order/Pdf/Items/Invoice/DefaultInvoice.php class.

[Avanor]

Thanks for getting back to me.

I've had a look at the plug-ins link - it all sounds very complicated. It now appears to be very hard to do something that used to be fairly simple!

 I'm not looking to be a Magento developer as such, I just want to amend the layout of the invoice a bit.

Can you explain further with regards to what I need to do, with regards to using a plugin or a preference to modify the vendor/magento/module-sales/Model/Order/Pdf/Items/Invoice/DefaultInvoice.php file. Thanks.