block hierarchy and settings

[dgpalmer]

It is unfortunate that in this current implementation of theme blocks, that we cannot pass parameters to dynamic blocks, such as settings from the parent block. It is especially frustrating that a parent block, cannot read it's children block settings.

With section blocks, you could do clever things like filtering for a certain block type, and then passing that block to another block to accommodate that use case. Some high level examples:

Here is an example of when you may need to do that.

Let's say you have a large catalog shop and a "Mega Menu" with 3 tiers of navigation. See this example from nordstrom.com (This is not my site, it is just an example)

You can see there are unique "promo" cards under parent level menu. In order to do this with shopify's navigation structure, it's best to have a "panel block" that gets assigned to a menu index. With me so far?

In a nested block world, it would be lovely to put those cards inside of the panel, that's a great use case for a nested theme block. That would work fine.

The struggle though is accessing that setting for the index in the panel, through the new theme blocks. In the existing section blocks approach, I can simply filter for my mega menu panel blocks and then loop through my menu, and render the appropriate panel for the appropriate index.

Keep in mind that we have a parent level navigation block that controls logic of what type of menu to render and all that fun stuff.

tldr; it would be nice if parent & children nested blocks could access one another's settings.

[PaulNewton]

A counterpoint for different inline content is using metaobjects in areas like mega menus.
However in @dgpalmer's example you've now got a merchant hopping through ~5 systems to set things up and there needs to a be a real good reason for that...that is NOT an architecture limitation against message passing.

Other examples are slideshows/tabs have to be inflexibly made as section-blocks if you want to have things like paging-indicators that have the unique id of a slide, or tab systems etc. Otherwise you can try to do it with dynamic-blocks(nestable blocks) but end up having to either try {% capture %} parsing, or have a HTML structure that can use CSS-grid or position tricks to yoink elements in a hierarchy to another area of the sections layout.

tangentially related because of unique-id issues: Shopify/dawn#2483

[eballeste]

a use case would be adding a setting that would affect all children blocks. example, a custom accent color.
the current solution is to set this up on the individual nested block level, which is annoying.

rethinking this: going to have to pass this down as a css variable