apply_filters( 'the_content', string $content )
Filters the post content.
Parameters Parameters
- $content
-
(string) Content of the current post.
More Information More Information
This filter is used to filter the content of a post after it is retrieved from the database and before it is printed to the screen.
Usage Usage
When using this filter it’s important to check if you’re filtering the content in the main query with the conditionals is_main_query() and in_the_loop(). The main post query can be thought of as the primary post loop that displays the main content for a post, page or archive. Without these conditionals you could unintentionally be filtering the content for custom loops in sidebars, footers, or elsewhere.
add_filter( 'the_content', 'filter_the_content_in_the_main_loop', 1 );
function filter_the_content_in_the_main_loop( $content ) {
// Check if we're inside the main loop in a single Post.
if ( is_singular() && in_the_loop() && is_main_query() ) {
return $content . esc_html__( 'I’m filtering the content inside the main loop', 'wporg');
}
return $content;
}
Source Source
Changelog Changelog
| Version | Description |
|---|---|
| 0.71 | Introduced. |
User Contributed Notes User Contributed Notes
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You can choose whether $content will have Shortcodes processed before or after your
the_contentfunction has executed by setting the Priority inadd_filter. The default (10) will process Shortcodes after you have returned $content at the end of your Filter function. A large figure, such as 99, will already have processed Shortcodes before your Filter function is passed $content.Note that
the_contentfilter isn’t used whenget_the_content()function is called.Example
/* Add a paragraph only to Pages. */ function my_added_page_content ( $content ) { if ( is_page() ) { return $content . '<p>Your content added to all pages (not posts).</p>'; } return $content; } add_filter( 'the_content', 'my_added_page_content');Consolidate multiple string replacement filters
String replacements are a common reason for filtering
the_contentand with PHP7 you can now consolidate multiple callback functions usingpreg_replace_callback_array();if it makes sense to.Example:
add_filter( 'the_content', 'multiple_string_replacements'); function multiple_string_replacements ( $content ) { if ( is_single() && in_the_loop() && is_main_query() ) { return preg_replace_callback_array([ // 1. Removes WordPress injected <p> tags surrounding images in post content. '/<p>\s*(<a .*>)?\s*(<img .* \/>)\s*(<\/a>)?\s*<\/p>/iU' => function ( &$matches ) { return $matches[1] . $matches[2] . $matches[3]; }, // 2. Adds custom data-attribute to <p> tags providing a paragraph id number. '|<p>|' => function ( &$matches ) { static $i = 1; return sprintf( '<p data-p-id="%d">', $i++ ); }, ], $content ); } return $content; }Expand full source codeCollapse full source code
the info at the bottom of the hook is wrong for most of the hooks :
Used by 7 functions | Uses 0 functions (At least it could be 0 function … ah ah ah !)
HERE is what i have for WP 5.1 :
* (7 is right, 0 is wrong)
* and i am not counting apply_filters_ref_array (happily there is no for “the_content” )
apply_filter
the_content comment.php 2656
the_content feed.php 191
the_content formatting.php 3692
the_content post-template.php 247
the_content class-wp-rest-attachments-controller.php 310
the_content class-wp-rest-posts-controller.php 1532
the_content class-wp-rest-revisions-controller.php 545
add_filter
the_content blocks.php 269
the_content blocks.php 296
the_content class-wp-embed.php 32
the_content class-wp-embed.php 39
the_content default-filters.php 142
the_content default-filters.php 172
the_content default-filters.php 173
the_content default-filters.php 174
the_content default-filters.php 175
the_content default-filters.php 176
the_content default-filters.php 177
the_content default-filters.php 178
the_content default-filters.php 519
There should be an indication of the WP version.
my doc (WP 5.1) is available here (https://blog.mailpress.org/hooks/wordpress-5-1/) !
The usage example is misleading. Unless you’re not interested in pages, it should be
if ( ( is_single() || is_page() ) && in_the_loop() && is_main_query() ) { ... }You should also add a sufficiently high priority to the filter to hook on
the_contentbefore rendering happens:add_filter( 'the_content', 'filter_the_content_in_the_main_loop', -1 ); function filter_the_content_in_the_main_loop( $content ) { // Check if we're inside the main loop in a post or page. if ( ( is_single() || is_page() ) && in_the_loop() && is_main_query() ) { return $content . esc_html__("I'm filtering the content inside the main loop", "my-textdomain"); } return $content; }This should go in functions.php.
It took me half a day to figure out why my filter was doing nothing.
Feedback
Thanks, the example was edited accordingly. — By Jb Audras —
This is also a good hook to use if you want to display custom fields from a plugin (including ACF fields).
The following example is from Jeff Starr’s plugins course.
// display all custom fields for each post function wpdocs_display_all_custom_fields( $content ) { $custom_fields = 'Custom Fields'; $all_custom_fields = get_post_custom(); foreach ( $all_custom_fields as $key => $array ) { foreach ( $array as $value ) { if ( '_' !== substr( $key, 0, 1 ) ) { $custom_fields .= ''. $key .' => '. $value .''; } } } return $content . $custom_fields; } add_filter( 'the_content', 'wpdocs_display_all_custom_fields' );Expand full source codeCollapse full source code
Using the example to add classes to
ptag &h2tag.<?php function wpdocs_replace_content( $text_content ) { if ( is_page() ) { $text = array( '<p>' => '<p class="text-danger">', '<h2>' => '<h2 class="h2">', ); $text_content = str_ireplace( array_keys( $text ), $text, $text_content ); } return $text_content; } add_filter( 'the_content', 'wpdocs_replace_content' ); ?>Expand full source codeCollapse full source code
Using the example below verifies that if the ALT attribute of any image inserted in the content is empty, get the file name.
function wpdocs_replaceALT( $content ) { if ( is_single() && in_the_loop() && is_main_query() ) { libxml_use_internal_errors( true ); $post = new DOMDocument(); $post->loadHTML( $content ); $images = $post->getElementsByTagName( 'img' ); foreach ( $images as $image ) { if ( empty( $image->getAttribute( 'alt' ) ) ) { $src = $image->getAttribute( 'src' ); $alt = pathinfo( $src, PATHINFO_FILENAME ); $image->setAttribute( 'alt', $alt ); } } $content = $post->saveHTML(); return $content; } } add_filter( 'the_content', 'wpdocs_replaceALT' );Expand full source codeCollapse full source code
Feedback
The note will not work with content with accent.. there is a problem with encoding.. should use :
— By keusta —