Fair warning: This might be a bit complicated. We have two types of collections in Sections. One is a collection of section; it’s a helper object which can sort and fetch sections for us. But in this case we’re talking about a Collection Column.
Templating a Collection Column works just like templating a regular column. With a few differences:
Loops in WordPress can get pretty complex. Especially when you add stuff like pagination, multiple rows of blocks, etc. So a collection-column template currently contains more logic then one would expect in a template. This makes it harder to extend when we also need to take backwards compatibility into account. If you can, also try and use a filter to solve your problem.
Collections usually contain other templates. One of those template-types is a block, which we’ll get to later. For now; also note that there will be seperate “element”-type templates for Pagination or the Autoloader. You can read up on these templates over at the “Templating Elements” page
Post type blocks are the templates that get loaded when we create a collection column. The collection will query a certain post-type (or multiple post-types) and loop through them. With each iteration it will load a post-type block, dependant on which post-type is currently in the loop.
A post type block will usually consist of a link, title, post thumbnail, post date and an excerpt. You can obviously make this as big as you would want. The point being that a single blog post on a single url probably will look vastly different than that post in an overview.
The hierarchy for these templates looks like this:
Section > Collection-column > Post-type block
A post type block template will always look at your theme like this:
/my-theme/collections/blocks/{post_type slug}.php
So if you’re creating a block for a regular post, do so like this:
/my-theme/blocks/post.php
<a href="<?php the_permalink();?>" class="post">
<h2><?php the_title();?></h2>
<?php the_post_thumbnail();?>
</a>
This example creates a link per post and displays the post’s title and thumbnail.