is_active_sidebar( string|int $index ): bool
- Since
- 2.8.0
- Source
wp-includes/widgets.php:985
Description
For more information on this and similar theme functions, check out the https://developer.wordpress.org/themes/basics/conditional-tags/ Conditional Tags article in the Theme Developer Handbook.
Compatibility
- WordPress
- since 2.8.0
- PHP
- 7.4–8.6-dev
- 6.7.7
- 6.8.8
- 6.9.7
- 7.0.4
- 7.1.0
Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.
Parameters
$indexstring|int- Sidebar name, id or number to check.
Return value
bool- True if the sidebar has widgets, false otherwise.
Performance profile
How much work a call to is_active_sidebar() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Moderate
- Scaling
- Constant
- Instructions
- 17–19
- Plugin surface
- 1 hook
- Called by
- 16
Reads stored settings via get_option(), cached per request but not free on a cold cache.
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 21.
Third-party callbacks on 'is_active_sidebar' run inside this call, and their cost is not bounded by anything here.
16 places in core call this, so the cost is paid more often than your own code shows.
What it touches
- hookthird-party callbacks
apply_filters()called directly - optionoption read or write
get_option()one call below is_active_sidebar()
Further down the call graph this can also reach cache, serialize, query and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.
What one call costs · 2 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost is_active_sidebar() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
is_int($index) | 17 | wp_get_sidebars_widgets(), apply_filters() |
!is_int($index) | 19 | sanitize_title(), wp_get_sidebars_widgets(), apply_filters() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 20 | 17–18 | 1 | 1 fewer instruction than PHP 8.5 |
| 8.5 | 21 | 17–19 | 1 | |
| 8.4 | 21 | 17–19 | 1 | |
| 8.3 | 21 | 17–19 | 1 | |
| 8.2 | 21 | 17–19 | 1 | |
| 8.1 | 21 | 17–19 | 1 | 1 fewer instruction than PHP 7.4 |
| 7.4 | 22 | 18–19 | 1 |
An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.
Hooks and filters fired · 1
One hook fires while is_active_sidebar() runs, in this order:
- apply_filters( is_active_sidebar )filterline 999 (+14 into the body)
Filters whether a dynamic sidebar is considered "active".
Uses · 3
- sanitize_title()Sanitizes a string into a slug, which can be used in URLs or HTML attributes.
- wp_get_sidebars_widgets()Retrieves the full list of sidebars and their widget instance IDs.
- apply_filters()Calls the callback functions that have been added to a filter hook.
Used by · 16
- twenty_twenty_one_body_classes()Adds custom classes to the array of body classes.
- twentyeleven_footer_sidebar_class()Counts the number of footer sidebars to enable dynamic classes for the footer.
- twentyfourteen_body_classes()Extends the default WordPress body classes.
- twentyfourteen_post_thumbnail()Displays an optional post thumbnail.
- twentyfourteen_scripts()Enqueues scripts and styles for the front end.
- twentyseventeen_body_classes()Adds custom classes to the array of body classes.
- twentyseventeen_content_image_sizes_attr()Adds custom image sizes attribute to enhance responsive image functionality for content images.
- twentyseventeen_content_width()Sets the content width in pixels, based on the theme's design and stylesheet.
- twentyseventeen_is_view_with_layout_option()Returns whether we're on a view that supports a one or two column layout.
- twentysixteen_body_classes()Adds custom classes to the array of body classes.
- twentysixteen_post_thumbnail_sizes_attr()Adds custom image sizes attribute to enhance responsive image functionality for post thumbnails
- twentythirteen_body_class()Extends the default WordPress body classes.
Show all 16
- twentythirteen_scripts_styles()Enqueues scripts and styles for the front end.
- twentytwelve_body_class()Extends the default WordPress body classes.
- twentytwelve_content_width()Adjusts content width in certain contexts.
- twentytwenty_body_classes()Adds conditional body classes.
Source code
function is_active_sidebar( $index ) { $index = ( is_int( $index ) ) ? "sidebar-$index" : sanitize_title( $index ); $sidebars_widgets = wp_get_sidebars_widgets(); $is_active_sidebar = ! empty( $sidebars_widgets[ $index ] ); /** * Filters whether a dynamic sidebar is considered "active". * * @since 3.9.0 * * @param bool $is_active_sidebar Whether or not the sidebar should be considered "active". * In other words, whether the sidebar contains any widgets. * @param int|string $index Index, name, or ID of the dynamic sidebar. */ return apply_filters( 'is_active_sidebar', $is_active_sidebar, $index );}Changelog
Introduced in 2.8.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
About this page
- Parsed data
- Generated from the wordpress-develop 7.1.0 tag, from
src/wp-includes/widgets.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it. - Corrections
- Something wrong on this page? Report it and it gets fixed in the next regeneration.