Remove "remove" tags from checkout

[barbazul]

There are a bunch of unnecessary <remove> tags in checkout.xml (and now in the corresponding layout.xml file) which remove either the left or the right column.

By unnecessary I mean that they are usually redundant with the template being assigned to root. i.e. in <checkout_cart_index> root template is page/1column.phtml but there are also a <remove name="left" /> and <remove name="right" /> tags. Same thing happens for almost every other handler in that layout.

This is a problem because there is no <unremove> (I'm fine with that btw) so there is no way to change the root layout of checkout pages via local.xml

[magento-team]

@barbazul
Thank you for pointing this out. We have cleaned up all similar places where "remove" directive was excessive or referred to unused elements (will be rolled out in next updates).

In some places the "remove" directive cannot be deleted without substantial refactoring -- that's when it is used for purpose other from design customization. In some other rare places it is still used for design customization, but it is only in specific themes.

We will consider adopting a convention to refrain using "remove" directive in Magento Core code, so that 3rd-party customizations will have better flexibility.

[benmarks]

Apologies if I've missed related discussion somewhere, but if not:

It should be noted that the <remove /> directive is not functionally void in the context of <checkout_cart_index />. It saves the overhead of instantiating several child blocks which won't appear if the right block is not rendered, which is the case with the checkout/cart/index view by default. It would be appropriate for the core team to consider this.

That said, this topic comes up in literally every Magento U Fundamentals class. I characterize it as follows: "<remove /> is the 'unringable bell' where layout update XML is concerned; because of this, it should not be used by the core", which would leave available the option of using these blocks or their children. In other words, it should be left up to the end implementer to explicitly remove blocks which will not be rendered.

[magento-team]

@benmarks

It saves the overhead of instantiating several child blocks which won't appear if the right block is not rendered, which is the case with the checkout/cart/index view by default. It would be appropriate for the core team to consider this.

In current implementation of layout model (in Magento 2.x), there will be no blocks instantiated until all instructions of layout are read. We decoupled the process of building bare structure from creating full-fledged elements. In other words, we implement "lazy initialization" pattern for instantiating blocks when generating layout. You can inspect the Mage_Core_Model_Layout::generateElements() to see how exactly it is done.

[barbazul]

@mage2-team That's good news!