wp_should_load_separate_core_block_assets(): bool
- Since
- 5.8.0
- Source
wp-includes/script-loader.php:2704
Description
When this function returns true, other functions ensure that core blocks use their own separate stylesheets.
When this function returns false, all core blocks will use the single combined 'wp-block-library' stylesheet.
As a side effect, the return value will by default result in block assets to be loaded on demand, via the wp_should_load_block_assets_on_demand() function. This behavior can be separately altered via that function.
This only affects front end and not the block editor screens.
Compatibility
- WordPress
- since 5.8.0
- 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.
Return value
bool- Whether separate core block assets will be loaded.
Performance profile
How much work a call to wp_should_load_separate_core_block_assets() 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
- Trivial
- Scaling
- Constant
- Instructions
- 4–14
- Plugin surface
- 1 hook
- Called by
- 7
Touches nothing outside its own arguments.
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 15.
Third-party callbacks on 'should_load_separate_core_block_assets' run inside this call, and their cost is not bounded by anything here.
7 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
Further down the call graph this can also reach query, option, cache, serialize 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 · 4 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost wp_should_load_separate_core_block_assets() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
is_admin() | 4 | is_admin() |
!is_admin() && is_feed() | 7 | is_admin(), is_feed() |
!is_admin() && !is_feed() && wp_is_rest_endpoint() | 10 | is_admin(), is_feed(), wp_is_rest_endpoint() |
!is_admin() && !is_feed() && !wp_is_rest_endpoint() | 14 | is_admin(), is_feed(), wp_is_rest_endpoint(), apply_filters() |
Across PHP versions
Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 15 instructions, 4–14 executed per call, 3 branches. The work does not change between versions.
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 wp_should_load_separate_core_block_assets() runs, in this order:
- apply_filters( should_load_separate_core_block_assets )filterline 2720 (+16 into the body)
Filters whether block styles should be loaded separately.
Uses · 4
- is_admin()Determines whether the current request is for an administrative interface page.
- is_feed()Determines whether the query is for a feed.
- wp_is_rest_endpoint()Checks whether a REST API endpoint request is currently being handled.
- apply_filters()Calls the callback functions that have been added to a filter hook.
Used by · 7
- register_block_style_handle()Finds a style handle for the block metadata field.
- register_block_type_from_metadata()Registers a block type from the metadata stored in the `block.json` file.
- register_core_block_style_handles()Registers core block style handles.
- wp_common_block_scripts_and_styles()Handles the enqueueing of block scripts and styles that are common to both the editor and the front-end.
- wp_default_styles()Assigns default styles to $styles object.
- wp_load_classic_theme_block_styles_on_demand()Adds hooks to load block styles on demand in classic themes.
- wp_should_load_block_assets_on_demand()Checks whether block styles should be loaded only on-render.
Source code
function wp_should_load_separate_core_block_assets() { if ( is_admin() || is_feed() || wp_is_rest_endpoint() ) { return false; } /** * Filters whether block styles should be loaded separately. * * Returning false loads all core block assets, regardless of whether they are rendered * in a page or not. Returning true loads core block assets only when they are rendered. * * @since 5.8.0 * * @param bool $load_separate_assets Whether separate assets will be loaded. * Default false (all block assets are loaded, even when not used). */ return apply_filters( 'should_load_separate_core_block_assets', false );}Changelog
Introduced in 5.8.0. 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/script-loader.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.