[Feature] Show banner by category of post

Hi,

I have hacked this functionality in to the code for one of my sites, I hope this helps you.

Insert this into includes/location.class.php line 124

$ml_cats = get_the_category();
	        foreach( $ml_cats as $ml_cat )
	        {
	        	$categories[] = $ml_cat->term_id;
	        }

					$categories = array_merge(array('all'), $categories);

	        $args['meta_query'][] = array(
	            'key' => 'ml_advert_categories',
	            'value' => $categories,
	            'compare' => 'IN'
	        );

and includes/metaboxes.php line 31

// categories
	$categories = get_terms('category');
	$all_categories = array();

	foreach ($categories as $category) {
		if($category->parent)
		{
			$parent = get_category( $category->parent);
			$long_name = $parent->name . ' / ' . $category->name;
		}
		else
		{
			$long_name = $category->name;;
		}

		$all_categories[ $category->term_id ] = $long_name;
	}

	asort($all_categories);

	$all_categories = array('all' => 'All Categories') + $all_categories;

and then before the “Tag Archives *” section in the same file

array(
				'name' => 'Categories *',
				'desc' => 'Select categories on which to display advert',
				'id' => $prefix . 'categories',
				'type' => 'multicheck',
				'options' => $all_categories
			),

I tried this and I could select which categories I wanted etc. but when you go to the advert in question, there’s a big error code displaying above the ad at https://www.kmcharityteam.co.uk.gridhosted.co.uk/

Warning: array_merge() [function.array-merge]: Argument #2 is not an array in /var/sites/k/kmcharityteam.co.uk/public_html/wp-content/plugins/ml-adverts/includes/location.class.php on line 133

Line 133 is

$categories = array_merge(array('all'), $categories);

Never mind, I put the code in lcations.class.php under line 124.
On line 124 is a ‘}’ so it was the wrong side of it. Once I moved the ‘}’ underneath the code that I placed in, everything now behaves.

Thank you so much Andy Webb!