Display sidebar if blog

Question

I have two sidebars registered. One called Sidebar (sidebar-1) and the other called Blog Sidebar (sidebar-2).

I would like to display the Blog sidebar on the blog index and single posts. As WordPress doesn't have a conditional tag for the blog page, I have tried the following via sidebar.php:

<?php
if ( is_front_page() && is_home() ) {
  // Default homepage - Do nothing
} elseif ( is_front_page() ) {
  // Static homepage - Do nothing
} elseif ( is_home() && is_single() ) {
  // Display blog sidebar
?>

    <aside>
        <?php dynamic_sidebar( 'sidebar-2' ); ?>
    </aside>

<?php
    } else {
      // Display main sidebar
?>

    <aside>
        <?php dynamic_sidebar( 'sidebar-1' ); ?>
    </aside>

<?php } ?>

When I go to the blog index and single post, I'm expecting to see the Blog Sidebar (sidebar-2), but I'm seeing the Sidebar (sidebar-1) instead.

Via reading settings, I have selected a page for my blog posts.

Answer 1

There is no conditional tag for the blog page. You have to use both is_home() and is_front_page() to detect this page

When you use is_home() and is_front_page(), you have to use them in the right order to avoid bugs and to test every user configuration:

<?php
if ( is_front_page() && is_home() ) {
 // blog listings
} elseif ( is_front_page() ) {
 // static homepage
} elseif ( is_home() ) {
 // blog page
} else {
 //everything else
}
?>

Taken from https://codex.wordpress.org/Conditional_Tags

If you want to check it another way, the posts / frontpage is stored in the database as an option which we can get the data using get_option which we can use:

get_option('show_on_front');

We can then do a check on that like so:

$front_page_type = get_option('show_on_front');
if($front_page_type = 'posts') {
 // blog page
} else {
 // static front page
}