how to get the categories for a single post in a hierarchical way

Question

The question is simple.
Imagine that I have a post named 'Single Post' which is inside the category 'sub-cat' which is a child of 'parent-cat' which is a child of 'super-cat'. What I need to do is to display all the related categories within the post page in the following order:

super-cat > parent-cat > sub-cat > Single Post

Answer 1

<?php 
    the_category( ' > ', 'multiple', $post->ID); 
    echo ' > ';
    the_title();
?> 

This works correctly when the post is in just one category. But if it's in multiple categories, or if the category parents are also selected — in your case, if the post is also in super-cat and parent-cat — then it displays those categories twice.
So this is probably not going to do it for you.

I suspect some of the breadcrumb type plugins might have solved this though.

Answer 2

you need to sort the categories first.

// get categories of post in sorted order
$categories = sortCategories(get_the_category());     

foreach($categories AS $category) {
    echo $category->name; // Plot category name
}
echo get_the_title(); // Plot post name

function sortCategories($categories) { // Sorting the category
    usort($categories, "cmpCategories");
    return $categories;
}

function cmpCategories($category_1,$category_2) { // Sort function
    foreach(get_categories(array("parent" => $category_1->cat_ID)) AS $sub) {
        if($category_2->cat_ID == $sub->cat_ID) return -1;
    }
    return 1;
}

I hope this helped.

Answer 3

This should do the trick:

$cats = get_the_category(); //retrieve cats for post

foreach ($cats as $cat) { //go thru to find child one - means cat which has specified parent id
    if ($cat->category_parent != 0) {
        $child = $cat->term_taxonomy_id;
    }
}
echo get_category_parents( $child, TRUE, ' > ' );

First we get categories for particular post, then we find last child and then with get_category_parents we get whole tree of its parents...

Answer 4

Here my working solution for that:

$categories = get_the_category();

$ordering = array();
foreach( $categories as $index => $cat) {
    $ordering[$cat->parent] = $index;
}

$ordered_string = "";
$i = 0;
while( $ordering[$i] !== null ){
    $ordered_string .= '<li class="item-cat"><a href="'.get_category_link( $categories[$ordering[$i]]->term_id ).'">'.$categories[$ordering[$i]]->name.'</li>';

    $i = $categories[$ordering[$i]]->term_id;
}

echo $ordered_string;

It echoes the string ready for the breadcrumb, and with a little modification yo can get the categories ordered as array.

Answer 5

Old question but top result on Google for me. I couldn't quickly find a breadcrumb categorization, supporting multiple categories, so I created one and wrapped it in a ul for easy styling:

// breadcrumb categorization
$cats = wp_get_post_categories( get_the_ID() );  //post id
foreach($cats as $c) {
    $ancestors = array_merge( array_reverse( get_ancestors( $c, 'category' ) ), [$c] );
    echo '<ul class="post-categories">';
    foreach($ancestors as $id){
        echo '<li><a href="' . esc_url( get_category_link( $id) ) . '">' . get_cat_name( $id ) . '</a></li>';
    }
    echo '</ul>';
}