通过category_name检索wp_terms

Question

I'm trying to limit the retrieved testimonial (using get_terms ) by their category names. category_name = "xxx" doesn't seem to do anything so I'm at a loss.

function testimonial_shortcode( $atts ) {

    $cat = $atts['cat'];

        $testim='<div id="owl-demo" class="owl-carousel owl-theme">';    
        $terms = get_terms( array(
            'taxonomy' => 'testimonial',
            'category_name' => $cat,
            'hide_empty' => true,
            ) );
        foreach($terms as $custom_texonomy){
            $imageid=get_option("testimonial_".$custom_texonomy->term_id."_testimonials__image");

            $imgurl=wp_get_attachment_image_src( $imageid, 'full');

            $testim.=' <div class="item">
    ...

    }
    add_shortcode( 'testimonialcat', 'testimonial_shortcode' );

Answer 1

'category_name' isn't a valid argument for get_terms. The WP reference documentation here lists the acceptable arguments. The one you want is:

'name' : (string|array) Optional. Name or array of names to return term(s) for.

So, assuming $cat is the name you want to search for, try changing your get_terms arguments to:

$terms = get_terms( array(
        'taxonomy' => 'testimonial',
        'name' => $cat,
        'hide_empty' => true,
        ) );

Update:

get_terms only returns information about the term you searched for, as per your original question.

To get all posts associated with a term, you need to use get_posts and tax_query as follows:

    $myposts = get_posts(array(
        'showposts' => -1, // get all posts
        'post_type' => 'post', // change to whatever post type you want, or leave out if you want to get all post types
        'tax_query' => array( 
                          array( 
                            'taxonomy' => 'testimonial', 
                            'field' => 'name', 
                            'terms' => $cat
                         ))
    ));

Reference: get_posts documentation in WP Codex

Answer 2

category_name is not a valid arg for get_terms, try 'name' instead:

function testimonial_shortcode( $atts ) {

    $cat = $atts['cat'];

            $testim='<div id="owl-demo" class="owl-carousel owl-theme">';    
        $terms = get_terms( array(
            'taxonomy' => 'testimonial',
            'name' => $cat,
            'hide_empty' => true,
            ) );
        foreach($terms as $custom_texonomy){
            $imageid=get_option("testimonial_".$custom_texonomy->term_id."_testimonials__image");

            $imgurl=wp_get_attachment_image_src( $imageid, 'full');

            $testim.=' <div class="item">
    ...

    }
    add_shortcode( 'testimonialcat', 'testimonial_shortcode' );