Linked Questions

58
votes
4answers
34k views

Difference Between Filter and Action Hooks?

I have been looking at the plugin API a bit more in depth recently and I was wondering what real differences there were between action and filter hooks. They both are events that receive data as a ...
22
votes
2answers
3k views

How do filters and hooks really work in PHP

How does filters and hooks actually work in WordPress? I'm asking about something advanced. How is it implemented in PHP? E.g how does it collect all the hooks from the different plugins and "attach" ...
1
vote
2answers
3k views

Which hook callback has priority if both plugin and theme use the same hook?

If a theme and a plugin uses the same action hook, for example comment_form is used by both theme and plugin. Then , which one will be called first? the function associated with the theme's hook or ...
4
votes
2answers
2k views

Using add_filter() in Widgets

Just have a query reference the add_filter() function. Can you use this function inside a WordPress widget class. Example I have a widget with dynamic created code that I want to pass to another ...
1
vote
1answer
4k views

Validate form in functions.php, send errors back to template

I have a form in a template that upon submission should be validated, and any errors should be displayed, and if no errors, insert the data into the database. I'm new to wordpress, but my idea was ...
1
vote
1answer
2k views

How to add_filter/action to comment out CSS generated by admin function?

So in wp-includes/admin-bar.php there is a function that adds CSS styling to the page: function _admin_bar_bump_cb() { ?> <style type="text/css" media="screen"> html { margin-...
0
votes
2answers
2k views

Difference b/w Simple function call & do_action call

dear I unable to understand of simple function call & do_action function call. do_action: I hook function and I place this in my one template file for use in header template. add_action('...
0
votes
1answer
3k views

changing variable through filters or action hooks

it appears i have a problem with understanding how add_action,add_filter and apply_filters work. somewhat abbreviated, i have the following scenario: in a template file i have this while ( $...
0
votes
0answers
3k views

How does add_action 'comment_post' work?

I found an example how to How To AJAX-ify WordPress Comments. I tweak it little bit and so far everything works fine but I want to understand the code. Where did the arguments $comment_ID, $...
1
vote
1answer
2k views

Get errors from WP_Error to different variables

I have added multiple errors in the WP_ERROR. I want to get those errors separately in different variables. With the following code I can get all errors with foreach loop, but how can I assign them to ...
0
votes
2answers
804 views

Override the Wordpress core function wp_referer_field

I'd like to override the core Wordpress function wp_referer_field to change the value of $referer_field variable inside of it. I've found that wp_referer_field is not pluggable and that I need to ...
0
votes
1answer
1k views

How apply_filters work in WordPress?

I know that how do_action works in WordPress. function foobar_func( $atts ){ // Action hook before any output! do_action( 'dr_before_get_qod_text' ); echo "foo and bar"; } add_shortcode(...
0
votes
2answers
878 views

How to read out the excerpt length (for if-condition)

I'm trying to do is the following. If the excerpt length is shorter than 30 charakters, than do.. <?php if ( get_the_excerpt() <= 30 AND has_post_thumbnail() ) : ?> <div></div>...
1
vote
2answers
370 views

Calling apply_filters on non-documented hooks

I have been trying to learn how to write plugins and I thought the best way would be to look at other plugins. I was taking a look at this one and the first lines /** * Plugin Name: Media Library ...
0
votes
1answer
230 views

Returning or use form data using a hook?

I have built a plugin that allows a user to submit forms to a third party API via an API call. I'm wondering if it's possible to add in a hook right before (or after) the data gets sent to the third ...

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