Querying two taxonomies

Question

I've got two taxonomies: "type of guide", and "tools".

They look something like this:

Type of guide

- Article
- Video
- Cheat sheet

Tool

— Learning Management System

• Quiz Tool

  - Hide a grades column (article)
  - Creating a Gradebook (article)
  - Long Answer Question Steps (article)
  - Matching Questions (article)
  - True or False (article)
  
  - Using the Quiz Tool (video)
  
  - Using the Quiz Tool (cheat sheet)
  

• Notifications tool

• Grades Tool

The screenshot outlines the problem perfectly: I need to limit that tax-query to include only items that are tagged with "Quiz Tool".

Screen: http://cl.ly/0t3J143q0A1X2w2y2X2n

I'm trying to do it with a tax_query, with an AND relation:

$args = array(
        'tax_query' => array(
            'relation' => 'AND', 
            array(
                'taxonomy' => 'guide-type',
                'field' => 'slug',
                'terms' => 'video'
            ),
            array(
                'taxonomy' => 'tool',
                'field' => 'slug',
                'terms' => what do I put here to get the current tool (Quiz tool)? 
                )
        )
    );
    $query = new WP_Query( $args );

But I just can't figure out how to limit to only list items that are tagged with "Quiz Tool". Note the, "what do I put here" part.

Help appreciated.

UPDATE:

It just occurred to me that I don't have to query both taxonomies, instead exit the tax_query and use a 'get_the_category()' as part of the $args:

// The Query
    $args = array(
        'tax_query' => array(
            array(
                'taxonomy' => 'guide-type',
                'field' => 'slug',
                'terms' => 'self-paced '
            )
        ), 
        'category_name' => get_the_category()

Something like that? Any ideas how I could limit that 'category_name' to be the current one I'm looking at (Quiz Tool).

Terry

Answer 1

This helper function will return the ID of the term you are currently viewing (from any taxonomy - you can limit just to a specific taxonomy, or the built-in tag and category taxonomies).

It will return false if you are not on a taxonomy term archive page.

function wpse52578_get_current_term_id(){
    if( !is_tax() && !is_tag() && !is_category() )
       return false;

    //If we got this far we are on a taxonomy-term page
    // (or a tag-term or category-term page)
    $taxonomy = get_query_var( 'taxonomy' );
    $queried_object = get_queried_object();
    $term_id =  (int) $queried_object->term_id;

    return $term_id;
}

Then you can do something like the following:

$tool_term_id = wpse52578_get_current_term_id();
$tax_query = array( 
             'relation' => 'AND', 
             array(
                'taxonomy' => 'guide-type',
                'field' => 'slug',
                'terms' => 'video'
            ));

if( $tool_term_id ){
     $tax_query[] =  array(
                'taxonomy' => 'tool',
                'field' => 'id',
                'terms' => $tool_term_id
                )
 }

$args = array('tax_query' => $tax_query);
$query = new WP_Query( $args );

Note: I've not tested this

Answer 2

This should get all post data for the taxonomy "Tool" with term "Quiz Tool".

$posts = get_content_taxonomy('tool', 'quiz-tool');

function get_content_taxonomy($tax, $section){
    $wp_query = new WP_Query();
    $wp_query->query(array('posts_per_page' => -1, 'orderby' => 'title', 'order' => 'ASC', 'tax_query' => array(array('taxonomy' => $tax, 'field' => 'slug', 'terms' => $section))));
    $posts = $wp_query->posts;
    if(!empty($posts)){
        $return = $posts;
    }
    return $return;
}

Answer 3

Alternate way to do this is to use get_the_terms() to figure out what tax term page you're on, then pass that to the tax_query.

// Get an array of current terms, use the last one returned     

 $terms = get_the_terms( $post->ID, 'tool' );

    if ( $terms && ! is_wp_error( $terms ) ) { 
        $current_tax_terms = array();

        foreach ( $terms as $term ) {
            $current_tax_terms[] = $term->name;
        }

        //Use end to give me just the last term             
        $current_term = end($current_tax_terms);
    }

Now I can pass $current_term into my tax_query:

$args = array(
        'tax_query' => array(
            array(
                'taxonomy' => 'guide-type',
                'field' => 'slug',
                'terms' => 'self-paced'
            ),
            array(
                'taxonomy' => 'tool',
                'field' => 'slug',
                'terms' => $current_term
            )
        ), 
        'author_name' => 'saltcod'

    );
    $query = new WP_Query( $args );


    $the_query = new WP_Query( $args );

I'm returning the last item in the array, because that's tax page I'm on. You could return the value from any position in the array you wanted. I happened to want the last one and so used end(array).