apply_filters with multiple args and multiple add_filter

I’m using apply_filters to bridge the gap between plugins but am struggling with the arguments. There is one argument, an array, there are several implementations of add_filter to match apply_filters and each of them pass down the original array and add to it.

Seems that you can pass several arguments from apply_filter but add_filter can only return one argument, is this correct or how do you handle multiple arguments between add_filter calls?

I need to pass a second argument of an account ID, but it seems that by priority only the first add_filter gets to work with that argument. I plan to wrap up both arguments into a single array and pass that, so an array with an array as its first value and a user ID as its second argument.

Edited to add example

$error = apply_filters('check_for_more_errors', $userid, $error);

add_filter('check_for_more_errors', 'error_check_1', 1, 2);

function error_check($userid, $error){
    $error[] = get_user_meta($userid, 'Plugin 1 user error', true);
    return $error;
}

add_filter('check_for_more_errors', 'error_check_2', 2, 2);

// $userid below is actually $error returned from error_check_1 
function error_check_2($userid, $error){
    $error[] = get_user_meta($userid, 'Plugin 2 user error', true);
    return $error;
}

The above does not work as I expect or need. The filters seem to daisy chain with one the returning argument of the first one being passed as the argument to the next one.

I want both to get the $id variable and for the $error variable to be augmented as in the example.

$299 Affordable Web Design WordPress

This article was republished from its original source.
Call Us: 1(800)730-2416

Pixeldust is a 20-year-old web development agency specializing in Drupal and WordPress and working with clients all over the country. With our best in class capabilities, we work with small businesses and fortune 500 companies alike. Give us a call at 1(800)730-2416 and let’s talk about your project.

FREE Drupal SEO Audit

Test your site below to see which issues need to be fixed. We will fix them and optimize your Drupal site 100% for Google and Bing. (Allow 30-60 seconds to gather data.)

Powered by

apply_filters with multiple args and multiple add_filter

On-Site Drupal SEO Master Setup

We make sure your site is 100% optimized (and stays that way) for the best SEO results.

With Pixeldust On-site (or On-page) SEO we make changes to your site’s structure and performance to make it easier for search engines to see and understand your site’s content. Search engines use algorithms to rank sites by degrees of relevance. Our on-site optimization ensures your site is configured to provide information in a way that meets Google and Bing standards for optimal indexing.

This service includes:

  • Pathauto install and configuration for SEO-friendly URLs.
  • Meta Tags install and configuration with dynamic tokens for meta titles and descriptions for all content types.
  • Install and fix all issues on the SEO checklist module.
  • Install and configure XML sitemap module and submit sitemaps.
  • Install and configure Google Analytics Module.
  • Install and configure Yoast.
  • Install and configure the Advanced Aggregation module to improve performance by minifying and merging CSS and JS.
  • Install and configure Schema.org Metatag.
  • Configure robots.txt.
  • Google Search Console setup snd configuration.
  • Find & Fix H1 tags.
  • Find and fix duplicate/missing meta descriptions.
  • Find and fix duplicate title tags.
  • Improve title, meta tags, and site descriptions.
  • Optimize images for better search engine optimization. Automate where possible.
  • Find and fix the missing alt and title tag for all images. Automate where possible.
  • The project takes 1 week to complete.