What Are Conditional Tags in WordPress?
Conditional tags in WordPress are functions used in themes and plugins to determine specific conditions before executing code. They enable dynamic content display based on various factors, such as the type of page being viewed, user authentication status, or query parameters.
Commonly Used Conditional Tags
WordPress provides built-in conditional tags that developers can use to control when and where code runs within templates. These tags return true or false based on the specified condition.
Page Type Conditional Tags
These tags check if a specific type of page is being viewed:
- is_home(): Returns true if the homepage is displaying blog posts.
- is_front_page(): Returns true if the homepage is set to a static page.
- is_single(): Returns true if viewing a single post.
- is_page(): Returns true if viewing a static page.
- is_category(): Returns true if viewing a category archive.
- is_tag(): Returns true if viewing a tag archive.
- is_author(): Returns true if viewing an author’s archive page.
- is_archive(): Returns true if viewing any archive page.
User-Specific Conditional Tags
These tags check for user authentication and roles:
- is_user_logged_in(): Returns true if a user is logged in.
- current_user_can( $capability ): Checks if the current user has a specific capability.
Query Conditional Tags
These tags analyze query conditions:
- is_search(): Returns true if showing search results.
- is_404(): Returns true if a 404 error page is displayed.
- is_paged(): Returns true if viewing a paginated archive or post.
Hierarchical Conditional Tags
These tags check hierarchical relationships:
- is_child_theme(): Returns true if a child theme is active.
- has_parent(): A custom function to check if a post has a parent in hierarchical post types.
Device and User Agent Tags
While WordPress lacks built-in functions for detecting user devices, plugins or custom PHP functions can be used to check conditions based on HTTP headers or user agents.
Using Conditional Tags in Theme Development
Conditional tags are frequently used in index.php, header.php, footer.php, single.php, and similar files. They enable layout adjustments based on the current page type.
Example: Displaying Content on the Homepage
php
if ( is_front_page() ) {
echo '<h1>Welcome to the Homepage</h1>';
}
This ensures the message appears only on the homepage.
Example: Showing Content to Logged-in Users
php
if ( is_user_logged_in() ) {
echo '<p>Exclusive content for logged-in users.</p>';
}
This restricts content to authenticated visitors.
Example: Styling Based on Conditional Tags
Developers may use body_class() in header.php to affect styling:
“`php