do_feed()
- Since
- 2.1.0
- Source
wp-includes/functions.php:1606
Description
If the feed action does not have a hook, then the function will die with a message telling the visitor that the feed is not valid.
It is better to only have one hook for each feed.
Compatibility
- WordPress
- since 2.1.0
- 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.
Performance profile
How much work a call to do_feed() 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
- 26–37
- Plugin surface
- 1 hook
- Called by
- 0
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 37.
Third-party callbacks on 'do_feed_{$feed}' run inside this call, and their cost is not bounded by anything here.
Nothing in core calls this; the cost is only what you spend yourself.
What it touches
- hookthird-party callbacks
do_action()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 do_feed() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
$feed !== "" && $feed !== "feed" && has_action() | 26 | get_query_var(), has_action(), do_action() |
has_action() | 27–29 | get_query_var(), get_default_feed(), has_action(), do_action() |
$feed !== "" && $feed !== "feed" && !has_action() | 34 | get_query_var(), has_action(), __(), wp_die(), do_action() |
!has_action() | 35–37 | get_query_var(), get_default_feed(), has_action(), __(), wp_die(), do_action() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 37 | 26–37 | 3 | |
| 8.5 | 37 | 26–37 | 3 | |
| 8.4 | 37 | 26–37 | 3 | 3 fewer instructions than PHP 8.3 |
| 8.3 | 40 | 29–40 | 3 | |
| 8.2 | 40 | 29–40 | 3 | |
| 8.1 | 40 | 29–40 | 3 | |
| 7.4 | 40 | 29–40 | 3 |
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 do_feed() runs, in this order:
Uses · 6
- get_query_var()Retrieves the value of a query variable in the WP_Query class.
- get_default_feed()Retrieves the default feed.
- has_action()Checks if any action has been registered for a hook.
- wp_die()Kills WordPress execution and displays HTML page with an error message.
- __()Retrieves the translation of $text.
- do_action()Calls the callback functions that have been added to an action hook.
Source code
function do_feed() { global $wp_query; $feed = get_query_var( 'feed' ); // Remove the pad, if present. $feed = preg_replace( '/^_+/', '', $feed ); if ( '' === $feed || 'feed' === $feed ) { $feed = get_default_feed(); } if ( ! has_action( "do_feed_{$feed}" ) ) { wp_die( __( '<strong>Error:</strong> This is not a valid feed template.' ), '', array( 'response' => 404 ) ); } /** * Fires once the given feed is loaded. * * The dynamic portion of the hook name, `$feed`, refers to the feed template name. * * Possible hook names include: * * - `do_feed_atom` * - `do_feed_rdf` * - `do_feed_rss` * - `do_feed_rss2` * * @since 2.1.0 * @since 4.4.0 The `$feed` parameter was added. * * @param bool $is_comment_feed Whether the feed is a comment feed. * @param string $feed The feed name. */ do_action( "do_feed_{$feed}", $wp_query->is_comment_feed, $feed );}Changelog
Introduced in 2.1.0. 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 6.8.8 tag, from
src/wp-includes/functions.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it. - Corrections
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