<?php
add_filter('wpseo_title', 'vozrastofilter_title');
function vozrastofilter_title($title) {
    if(  is_page(352) ) {
    	$age_tag = (int)$_GET['age_tag'];

    	if ( $age_tag ) {
    		$yoast_title = get_post_meta( get_the_ID(), '_yoast_wpseo_title', true );

    		$title_period = "";
			if($age_tag == 1000) $title_period = "Ребенок-школьник";
			if($age_tag == 11) $title_period = "11 мес.";
			if($age_tag == 10) $title_period = "10 мес.";
			if($age_tag == 9) $title_period = "9 мес.";
			if($age_tag == 8) $title_period = "8 мес.";
			if($age_tag == 7) $title_period = "7 мес.";
			if($age_tag == 4) $title_period = "4-6 мес.";
			if($age_tag == 1) $title_period = "1-3 мес.";
			if($age_tag == 700) $title_period = "7 лет";
			if($age_tag == 600) $title_period = "6 лет";
			if($age_tag == 500) $title_period = "5 лет";
			if($age_tag == 400) $title_period = "4 года";
			if($age_tag == 300) $title_period = "3 года";
			if($age_tag == 200) $title_period = "2 года";
			if($age_tag == 100) $title_period = "1 год";

        	$title = $yoast_title.' - '.$title_period;
    	}
    }
    return $title;
}

add_filter( 'wpseo_metadesc', 'vozrastofilter_description', 10, 1 );
function vozrastofilter_description($description) {
    if(  is_page(352) ) {
    	$age_tag = (int)$_GET['age_tag'];

    	if ( $age_tag ) {
    		$yoast_description = get_post_meta( get_the_ID(), '_yoast_wpseo_metadesc', true );

    		$title_period = "";
			if($age_tag == 1000) $title_period = "Ребенок-школьник";
			if($age_tag == 11) $title_period = "11 мес.";
			if($age_tag == 10) $title_period = "10 мес.";
			if($age_tag == 9) $title_period = "9 мес.";
			if($age_tag == 8) $title_period = "8 мес.";
			if($age_tag == 7) $title_period = "7 мес.";
			if($age_tag == 4) $title_period = "4-6 мес.";
			if($age_tag == 1) $title_period = "1-3 мес.";
			if($age_tag == 700) $title_period = "7 лет";
			if($age_tag == 600) $title_period = "6 лет";
			if($age_tag == 500) $title_period = "5 лет";
			if($age_tag == 400) $title_period = "4 года";
			if($age_tag == 300) $title_period = "3 года";
			if($age_tag == 200) $title_period = "2 года";
			if($age_tag == 100) $title_period = "1 год";

        	$description = $yoast_description.' Значение фильтра - '.$title_period;
    	}
    }
    return $description;
}

add_filter( 'wpseo_canonical', 'vozrastofilter_canonical' );
function vozrastofilter_canonical($url) {
    if(  is_page(352) ) {
    	$age_tag = (int)$_GET['age_tag'];
    	$yoast_canonical = get_post_meta( get_the_ID(), '_yoast_wpseo_canonical', true );

		$url = get_permalink().'?age_tag='.$age_tag;
    }

    return $url;
}

add_filter( 'wpseo_next_rel_link', 'remove_rel_next_cat_mozhno' );
function remove_rel_next_cat_mozhno($link) {
	if ( is_category(4) ) {
		$link = '';
	}

	return $link;
}

add_filter( 'wpseo_next_rel_link', '__return_false' );
add_filter( 'wpseo_prev_rel_link', '__return_false' );