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I have a hierarchical taxonomy called 'geographical locations'. It contains continents on a first level, and then the countries for each one. Example :
Europe
- Ireland
- Spain
- Sweden
Asia
- Laos
- Thailand
- Vietnam
etc.
Using get_terms() I managed to output the full list of terms, but the continents get mixed up with the countries, in one big flat list.
How can I output a hierarchical list like above?
Use wp_list_categories with the taxonomy argument, it's built for creating hierarchal category lists but will also support using a custom taxonomy..
Codex Example:
Display terms in a custom taxonomy
If the list comes back looking flat it's possible you just need a little CSS to add padding to the lists, so you can see their hierarchal structure.
I realise this is a very old question, but if you have a need to build up an actual structure of terms, this might be a useful method for you:
/**
* Recursively sort an array of taxonomy terms hierarchically. Child categories will be
* placed under a 'children' member of their parent term.
* @param Array $cats taxonomy term objects to sort
* @param Array $into result array to put them in
* @param integer $parentId the current parent ID to put them in
*/
function sort_terms_hierarchicaly(Array &$cats, Array &$into, $parentId = 0)
{
foreach ($cats as $i => $cat) {
if ($cat->parent == $parentId) {
$into[$cat->term_id] = $cat;
unset($cats[$i]);
}
}
foreach ($into as $topCat) {
$topCat->children = array();
sort_terms_hierarchicaly($cats, $topCat->children, $topCat->term_id);
}
}
Usage is as follows:
$categories = get_terms('my_taxonomy_name', array('hide_empty' => false));
$categoryHierarchy = array();
sort_terms_hierarchicaly($categories, $categoryHierarchy);
var_dump($categoryHierarchy);
$into[$cat->term_id] = $cat; into $into[] = $cat; Having the ID of the term as the array key is annoying (you can't get the first element easily using the 0 key) and useless (you're already storing the $cat object and you can get the id using the term_id property.
– Nahuel
Mar 7 '17 at 15:03
I dont know of any function that does what you want but you can build up something like this:
<ul>
<?php $hiterms = get_terms("my_tax", array("orderby" => "slug", "parent" => 0)); ?>
<?php foreach($hiterms as $key => $hiterm) : ?>
<li>
<?php echo $hiterm->name; ?>
<?php $loterms = get_terms("my_tax", array("orderby" => "slug", "parent" => $hiterm->term_id)); ?>
<?php if($loterms) : ?>
<ul>
<?php foreach($loterms as $key => $loterm) : ?>
<li><?php echo $loterm->name; ?></li>
<?php endforeach; ?>
</ul>
<?php endif; ?>
</li>
<?php endforeach; ?>
</ul>
I haven't tested this but you can see what I'm getting at. What the above code will do is give you only two levels
EDIT: ahh yes you can use wp_list_categories() to do what you after.
wp_list_categories() to add in your GET parameters. Or even better build a filter for the function to add in the bits you want. Don't ask me how you do that as I've not yet been able to get my head around it :(
– Brady
Apr 13 '11 at 15:19
wp_list_categories if you want greater control over the output, it'll make your code much more reusable..
– t31os
Apr 13 '11 at 16:09
You can use wp_list_categories(), with a 'taxonomy' argument.
As I was looking for the same but to get terms of one post, finally I compiled this, and it works for me.
What it does :
• it gets all terms of a taxonomy name for a specific post.
• for a hierachical taxonomy with two levels (ex: level1:'country' and level2:'cities'), it creates a h4 with the level1 followed by an ul list of level2 and this for all level1 items.
• if the taxonomy is not hierarchical, it will create only an ul list of all items.
here is the code (I write it for me so I tried to be as generic as I can but...) :
function finishingLister($heTerm){
$myterm = $heTerm;
$terms = get_the_terms($post->ID,$myterm);
if($terms){
$count = count($terms);
echo '<h3>'.$myterm;
echo ((($count>1)&&(!endswith($myterm, 's')))?'s':"").'</h3>';
echo '<div class="'.$myterm.'Wrapper">';
foreach ($terms as $term) {
if (0 == $term->parent) $parentsItems[] = $term;
if ($term->parent) $childItems[] = $term;
};
if(is_taxonomy_hierarchical( $heTerm )){
foreach ($parentsItems as $parentsItem){
echo '<h4>'.$parentsItem->name.'</h4>';
echo '<ul>';
foreach($childItems as $childItem){
if ($childItem->parent == $parentsItem->term_id){
echo '<li>'.$childItem->name.'</li>';
};
};
echo '</ul>';
};
}else{
echo '<ul>';
foreach($parentsItems as $parentsItem){
echo '<li>'.$parentsItem->name.'</li>';
};
echo '</ul>';
};
echo '</div>';
};
};
So finally you call the function with this (obviously, you replace my_taxonomy by yours) : finishingLister('my_taxonomy');
I don't pretend it's perfect but as I said it works for me.
The following code will generate drop-down with terms, but also can generate any other element/structure by editing the $outputTemplate variable, and editing str_replace lines:
function get_terms_hierarchical($terms, $output = '', $parent_id = 0, $level = 0) {
//Out Template
$outputTemplate = '<option value="%ID%">%PADDING%%NAME%</option>';
foreach ($terms as $term) {
if ($parent_id == $term->parent) {
//Replacing the template variables
$itemOutput = str_replace('%ID%', $term->term_id, $outputTemplate);
$itemOutput = str_replace('%PADDING%', str_pad('', $level*12, ' '), $itemOutput);
$itemOutput = str_replace('%NAME%', $term->name, $itemOutput);
$output .= $itemOutput;
$output = get_terms_hierarchical($terms, $output, $term->term_id, $level + 1);
}
}
return $output;
}
$terms = get_terms('taxonomy', array('hide_empty' => false));
$output = get_terms_hierarchical($terms);
echo '<select>' . $output . '</select>';
I had this problem and none of the answers here worked for me, for one reason or another.
Here is my updated and working version.
function locationSelector( $fieldName ) {
$args = array('hide_empty' => false, 'hierarchical' => true, 'parent' => 0);
$terms = get_terms("locations", $args);
$html = '';
$html .= '<select name="' . $fieldName . '"' . 'class="chosen-select ' . $fieldName . '"' . '>';
foreach ( $terms as $term ) {
$html .= '<option value="' . $term->term_id . '">' . $term->name . '</option>';
$args = array(
'hide_empty' => false,
'hierarchical' => true,
'parent' => $term->term_id
);
$childterms = get_terms("locations", $args);
foreach ( $childterms as $childterm ) {
$html .= '<option value="' . $childterm->term_id . '">' . $term->name . ' > ' . $childterm->name . '</option>';
$args = array('hide_empty' => false, 'hierarchical' => true, 'parent' => $childterm->term_id);
$granchildterms = get_terms("locations", $args);
foreach ( $granchildterms as $granchild ) {
$html .= '<option value="' . $granchild->term_id . '">' . $term->name . ' > ' . $childterm->name . ' > ' . $granchild->name . '</option>';
}
}
}
$html .= "</select>";
return $html;
}
And usage:
$selector = locationSelector('locationSelectClass');
echo $selector;
I used @popsi code that was working really well and I made it a more efficient and easy to read:
/**
* Recursively sort an array of taxonomy terms hierarchically. Child categories will be
* placed under a 'children' member of their parent term.
* @param Array $cats taxonomy term objects to sort
* @param integer $parentId the current parent ID to put them in
*/
function sort_terms_hierarchicaly(Array $cats, $parentId = 0)
{
$into = [];
foreach ($cats as $i => $cat) {
if ($cat->parent == $parentId) {
$cat->children = sort_terms_hierarchicaly($cats, $cat->term_id);
$into[$cat->term_id] = $cat;
}
}
return $into;
}
Usage :
$sorted_terms = sort_terms_hierarchicaly($terms);
Be sure that hierarchical=true is passed to your get_terms() call.
Note that hierarchical=true is the default, so really, just be sure that it hasn't been overridden to be false.
get_terms() will return a full list of the terms (as the OP stated) but not a hierarchical list showing parent / child relationship as requested.
– jdm2112
Mar 17 '16 at 5:00
Here I have four level dropdown select list with hidden first item
<select name="lokalizacja" id="ucz">
<option value="">Wszystkie lokalizacje</option>
<?php
$excluded_term = get_term_by('slug', 'podroze', 'my_travels_places');
$args = array(
'orderby' => 'slug',
'hierarchical' => 'true',
'exclude' => $excluded_term->term_id,
'hide_empty' => '0',
'parent' => $excluded_term->term_id,
);
$hiterms = get_terms("my_travels_places", $args);
foreach ($hiterms AS $hiterm) :
echo "<option value='".$hiterm->slug."'".($_POST['my_travels_places'] == $hiterm->slug ? ' selected="selected"' : '').">".$hiterm->name."</option>\n";
$loterms = get_terms("my_travels_places", array("orderby" => "slug", "parent" => $hiterm->term_id,'hide_empty' => '0',));
if($loterms) :
foreach($loterms as $key => $loterm) :
echo "<option value='".$loterm->slug."'".($_POST['my_travels_places'] == $loterm->slug ? ' selected="selected"' : '')."> - ".$loterm->name."</option>\n";
$lo2terms = get_terms("my_travels_places", array("orderby" => "slug", "parent" => $loterm->term_id,'hide_empty' => '0',));
if($lo2terms) :
foreach($lo2terms as $key => $lo2term) :
echo "<option value='".$lo2term->slug."'".($_POST['my_travels_places'] == $lo2term->slug ? ' selected="selected"' : '')."> - ".$lo2term->name."</option>\n";
endforeach;
endif;
endforeach;
endif;
endforeach;
?>
</select>
<label>Wybierz rodzaj miejsca</label>
<select name="rodzaj_miejsca" id="woj">
<option value="">Wszystkie rodzaje</option>
<?php
$theterms = get_terms('my_travels_places_type', 'orderby=name');
foreach ($theterms AS $term) :
echo "<option value='".$term->slug."'".($_POST['my_travels_places_type'] == $term->slug ? ' selected="selected"' : '').">".$term->name."</option>\n";
endforeach;
?>
</select>
