Force the use of a specific template, regardless of which template is selected. The wp_query_engine_template filter allows developers to select a template programmatically at the time of output, instead of specifying beforehand.
Filter the query arguments after processing. This allows developers to apply some specific formatting to the arguments after they've been normalized, but before being passed to WP_QUERY. At this point, the post id's that will be queried is already set, so fewer arguments can be applied.
By default, the template includes a loop with specific template actions already defined. The loop uses the template name to define custom actions.
The template name is normalized by removing spaces, dashes, and .php. If a template is defined by name, such as My Custom Template, it will be normalized to my_custom_template. A name specified by path, such as templates/homepage_loop.php, it will be normalized to templates_homepage_loop.
If you do not wish to include the default loop, and instead want to define your own loop in your custom template files, you can using the wp_query_include_loop filter.