Add Alt to image where it's empty in WordPress through functions.php

Add Alt to image where it’s empty in WordPress through functions.php

Adding following code to functions.php will add page title as a image alt to img tag:

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function callback($buffer) {

preg_match_all('/<img (.*?)\/>/', $buffer, $images);
	if(!is_null($images)) {
		foreach($images[1] as $index => $value) {
			preg_match('/alt="(.*?)"/', $value, $img);
			preg_match('/alt=\"(.*?)\"/', $value, $img2);
			
			preg_match('/data-src="(.*?)"/', $value, $imgurl);
			$title = "";
			$image_url = $imgurl[1];
          
          	//get alt from url in WordPress
    		global $wpdb;   		
    		$query_arr  = $wpdb->get_col( $wpdb->prepare( "SELECT ID FROM {$wpdb->posts} WHERE guid='%s';", strtolower( $image_url ) ) );
    		$image_id   = ( ! empty( $query_arr ) ) ? $query_arr[0] : 0;

$title =  get_post_meta( $image_id, '_wp_attachment_image_alt', true );
			
            // if there is no alt then get page title as alt
            if( empty( $title ) ) {
        		$title = get_the_title();
    		}
			
			if(!is_null($images)) {
				if((!isset($img[1]) || $img[1] == '') || (!isset($img2[1]) || $img2[1] == '')) {
					
					$new_img = str_replace('<img', '<img alt="'.$title.'"', $images[0][$index]);
					$buffer = str_replace($images[0][$index], $new_img, $buffer);
				}
			}
		}
	}

return $buffer;
}

function buffer_start() { ob_start(); }

function buffer_end() { echo callback(ob_get_clean()); }

add_action('wp', 'buffer_start', 0);
add_action('wp_footer', 'buffer_end');

By Mir Saeid|2020-12-10T12:38:37-05:00November 17th, 2019|Blog|0 Comments

About the Author: Mir Saeid

Experienced computer engineer with post graduate diploma in e-Business, Web Developer and Programmer

Add Alt to image where it’s empty in WordPress through functions.php