feed_content_type( string $type = '' ): string
- Since
- 2.8.0
- Source
wp-includes/feed.php:768
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
$typestringoptional- Type of feed. Possible values include 'rss', rss2', 'atom', and 'rdf'.Default:
''
Return value
string- Content type for specified feed type.
Performance profile
How much work a call to feed_content_type() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Trivial
- Scaling
- Constant
- Instructions
- 13–17
- Plugin surface
- 1 hook
- Called by
- 3
Touches nothing outside its own arguments.
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 18.
Third-party callbacks on 'feed_content_type' run inside this call, and their cost is not bounded by anything here.
3 places in core call this, so the cost is paid more often than your own code shows.
What it touches
- hookthird-party callbacks
apply_filters()called directly
What one call costs · 2 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost feed_content_type() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
!empty($type) | 13–14 | apply_filters() |
empty($type) | 16–17 | get_default_feed(), apply_filters() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 18 | 13–17 | 2 | |
| 8.5 | 18 | 13–17 | 2 | |
| 8.4 | 18 | 13–17 | 2 | |
| 8.3 | 18 | 13–17 | 2 | |
| 8.2 | 18 | 13–17 | 2 | |
| 8.1 | 18 | 13–17 | 2 | 1 fewer instruction than PHP 7.4 |
| 7.4 | 19 | 13–18 | 2 |
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 feed_content_type() runs, in this order:
- apply_filters( feed_content_type )filterline 791 (+23 into the body)
Filters the content type for a specific feed type.
Uses · 2
- get_default_feed()Retrieves the default feed.
- apply_filters()Calls the callback functions that have been added to a filter hook.
Used by · 3
- WP::send_headers()Sends additional HTTP headers for caching, content type, etc.
- feed_links()Displays the links to the general feeds.
- feed_links_extra()Displays the links to the extra feeds such as category feeds.
Source code
function feed_content_type( $type = '' ) { if ( empty( $type ) ) { $type = get_default_feed(); } $types = array( 'rss' => 'application/rss+xml', 'rss2' => 'application/rss+xml', 'rss-http' => 'text/xml', 'atom' => 'application/atom+xml', 'rdf' => 'application/rdf+xml', ); $content_type = ( ! empty( $types[ $type ] ) ) ? $types[ $type ] : 'application/octet-stream'; /** * Filters the content type for a specific feed type. * * @since 2.8.0 * * @param string $content_type Content type indicating the type of data that a feed contains. * @param string $type Type of feed. Possible values include 'rss', rss2', 'atom', and 'rdf'. */ return apply_filters( 'feed_content_type', $content_type, $type );}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/feed.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.