Using custom taxonomies in a query

Question

I'm using a plugin (IssueM) which gives the "articles" post-type a custom taxonomy called "Issues".

I'm trying to return all "articles" which have the taxonomy issue-one set (which is the slug name). But I cannot get it to return anything:

$the_query = new WP_Query(
array(
'post_type' => 'article',
'posts_per_page' => -1,
'taxonomy' => 'issue',
'term' => 'issue-one'
)
);

I'm not sure whether the taxonomy field needs to be issue or issues so I've tried both but neither work. I have tried the slug name for the term e.g issue-one and also the written name e.g Issue One.

I have been instructed elsewhere that I need to use a taxonomy query instead, here is what I have so far:

'tax_query' => array(
    array(
       'taxonomy' => 'Issues',
       'field'    => 'slug',
       'terms'    => 'issue-one'
    ),
 ),

Attempted the following, no luck:

$args = array(
    'post_type' => 'article',
    'tax_query' => array(
         array(
           'taxonomy' => 'Issues',
           'field'    => 'issuem_issue',
           'terms'    => 'issue-one'
     ),
 ),
 'posts_per_page' => -1
 );

Answer 1

I looked at the source code for IssueM. I think the slug you are after is issuem_issue

However, there are two more taxonomies it registers: issuem_issue_categories and issuem_issue_tags

Edit

Try changing your args to:

$args = array(
    'post_type' => 'article',
    'tax_query' => array(
         array(
           'taxonomy' => 'issuem_issue',
           'field'    => 'slug',
           'terms'    => 'issue-one'
     ),
 ),
 'posts_per_page' => -1
 );

This should all articles with the issuem_issue taxonomy slugged 'issue-one' attached to it.