Category_slug of category children wordpress - php

Question

I have a category "Decouverte" witch has three subcategories : "actualité", "vidéo" and "coup de coeur".
When I sort the posts according to their subcategories, everything works except for the category "video"; the category_slug displays "decouverte".
On my dashboard, I see this :
The subcategory "Video" is displayed last, maybe it's why it doesn't work ?
My code :
$categories = get_the_category();
$category_slug = $categories[0]->slug;
echo $category_slug;
if ( $category_slug == 'actualite' ) { ?>
<div class="picto_home icone_actualite"></div><?php
}
elseif ( $category_slug == 'video' ) { ?>
<div class="picto_home icone_video"></div><?php
}
elseif ( $category_slug == 'coupdecoeur' ) { ?>
<div class="picto_home icone_coupdecoeur"></div><?php
}
else { echo "Doesn't work"; } ?>
And the website : http://www.overso.me/ It's on the right block

Answer 1

Problem source
It's because you have got two categories applied to all posts.
Categories in each post are sotrted alphabetically.
In your case you take $category_slug = $categories[0]->slug;, which means:
Take first category slug name from categories array
For each post it is:
$categories[0] = Decouverte, $categories[1] = Video because D < V
$categories[0] = Actualite, $categories[1] = Decouverte because A < D
$categories[0] = Coup de coeur, $categories[1] = Decouverte because C < D
How to make it work as you want
Ok so here is my approach for your problem.
Before checking for $categories[0]->slug, lets check is $categories[0] object a PARENT category. You can do this by checking:
$categories = get_the_category();
// Remove parent category object from array if it's on first place
if($categories[0]->parent == 0){
unset($categories[0]);
$categories = array_values($categories);
}
As you see if $categories[0] is a parent category (if($categories[0]->parent == 0)), then remove this result from array $categories - unset($categories[0]).
Now you can just reset indexing of this array to starting from 0, by calling $categories = array_values($categories).
From now, you can easly call $categories[0]->slug, because there is no parent category on first place for sure.
Full code:
$categories = get_the_category();
// Remove parent category object from array if it's on first place
if($categories[0]->parent == 0){
unset($categories[0]);
$categories = array_values($categories);
}
$category_slug = $categories[0]->slug;
if ( $category_slug == 'child-1' ) {
echo "1111";
}
elseif ( $category_slug == 'child-2' ) {
echo "2222";
}
elseif ( $category_slug == 'child-3' ) {
echo "3333";
}
else { echo "Doesn't work"; }
Of course change if statements logic to your data.
More general solution for future reference
Ok, here is some general solution I wrote.
If you need to get only subcategories for any post, for any number of categories applied to the post, and no matter on which place parent category will be in the categories array, you should try this.
First, add this function to your functions.php file (or to your plugin file).
function du_get_post_subcategories( $post_id ){
$categories = get_the_category( $post_id );
$i = 0;
foreach ($categories as $category) {
if($category->parent == 0){
unset($categories[$i]);
}
$i++;
}
$categories = array_values($categories);
return $categories;
}
And then inside your loop you can call
$subcategories = du_get_post_subcategories( $post->ID );
If you have post ID, you can call this outside the loop as well
$subcategories = du_get_post_subcategories( $your_post_id );
This function will return all subcategories in the same format as get_the_category() function.
If you provide array with only one, parent category. Function will return an empty array.