Order Custom Taxonomy by Slug in Wordpress Plugin - php

Question

CONTEXT
We have created a custom taxonomy that is to be displayed as a search filter parameter in third party plugin (in the form of a checkbox). However, we want the list of taxonomies to be displayed ordered by slug.
This is the function that generates the checkbox and outputs the taxonomy - the part that we customized starts at " //create the attributes" .
public function checkbox($args)
{
//init defaults & vars
$input_args = $this->prepare_input_args($args, "checkbox");
$input_name = $input_args['attributes']['name'];
unset($input_args['attributes']['name']);
//filter the input arguments before the html is generated - allowing almost all options to be modified
if(has_filter('sf_input_object_pre')) {
$input_args = apply_filters('sf_input_object_pre', $input_args, $this->sfid);
}
//prepare html
$attibutes_html = $this->convert_attributes_to_html($input_args['attributes']);
$open_child_count = 0;
ob_start();
?>
<ul<?php echo $attibutes_html; ?>>
<?php
$last_option_depth = 0;
$option_count = count($input_args['options']);
$current_depth = 0;
$is_li_open = array();
//echo "<ul>";
for($i=0; $i<$option_count; $i++)
{
$option = &$input_args['options'][$i];
if(!isset($option->attributes))
{
$option->attributes = array(
'class' => '',
'id' => ''
);
}
//check a default has been set and set it
$option->attributes['type'] = "checkbox";
$option->attributes['value'] = $option->value;
$option->attributes['name'] = $input_name;
$option->attributes['html'] = '';
$container_attributes = array();
if($this->is_option_selected($option, $input_args['defaults']))
{
$option->attributes['checked'] = 'checked';
$option->attributes['class'] = trim($option->attributes['class']).' sf-option-active';
}
else
{
if(isset($option->attributes['checked']))
{
unset($option->attributes['checked']);
}
}
//now we want to put the class attribute on the LI, and remove from input
$option_class = $option->attributes['class'];
$option->attributes['class'] = $input_args['input_class'];
$input_id = $this->generate_input_id($input_name."_".$option->value);
$option->attributes['id'] = $input_id;
$container_attibutes_html = "";
if(isset($option->count))
{
$container_attributes['data-sf-count'] = $option->count;
$container_attibutes_html = $this->convert_attributes_to_html($container_attributes);
}
//create the attributes
$input_attibutes_html = $this->convert_attributes_to_html($option->attributes);
$option_label = $option->label;
$option_html = $option->attributes['value'];
if($input_name == "_sft_module_authors[]"){
$tax_name = "module_authors";
} else if ($input_name == "_sft_module_mindset[]") {
$tax_name = "module_mindset";
} else if ($input_name == "_sft_module_language[]") {
$tax_name = "module_language";
} else if ($input_name == "_sft_management_levels[]") {
$tax_name = "management_levels";
} else{
$tax_name = "wpdmcategory";
}
// Get the ID of a given category
$my_term = get_term_by('slug',$option->value,$tax_name);
$category_id = $my_term->term_id;
$category_desc = $my_term->description;
$category_name = $my_term->name;
$meta_image = get_wp_term_image($category_id);
// Get the URL of this category
$category_link = get_category_link( $category_id );
if ($input_name == "_sft_module_authors[]") {
echo '<li class="accordion-content '.$option_class.'"'.$container_attibutes_html.'><input '.$input_attibutes_html.'><label class="sf-label-checkbox" for="'.$input_id.'">' . $category_name . '</label><a class="eModal-post-'.$category_id.'" href="'.$category_link.'"><i class="fa fa-info-circle"></i></a>';
echo do_shortcode("[modal id='post-". $category_id ."' size='small' title='". $category_name ."']". "<div class='col-md-8'>" . $category_desc . "</div>" . "<div class='col-md-4'>" . "<div class='img-wrap'><img src='".$meta_image."'></div></div>" . "[/modal]");
} else if ($input_name == "_sft_module_mindset[]") {
echo '<li class="accordion-content '.$option_class.'"'.$container_attibutes_html.'><input '.$input_attibutes_html.'><label class="sf-label-checkbox" for="'.$input_id.'">' . $category_name . '</label><a class="eModal-post-'.$category_id.'" href="'.$category_link.'"><i class="fa fa-info-circle"></i></a>';
echo do_shortcode("[modal id='post-". $category_id ."' size='small' title='". $category_name ."']". "<div class='col-md-12'>" . $category_desc . "</div>" . "[/modal]");
} else if ($input_name == "_sft_module_language[]") {
echo '<li class="accordion-content '.$option_class.'"'.$container_attibutes_html.'><input '.$input_attibutes_html.'><label class="sf-label-checkbox" for="'.$input_id.'">' . $category_name;
} else if ($input_name == "_sft_management_level[]") {
echo '<li class="accordion-content '.$option_class.'"'.$container_attibutes_html.'><input '.$input_attibutes_html.'><label class="sf-label-checkbox" for="'.$input_id.'">' . $category_name;
} else {
echo '<li class="accordion-content '.$option_class.'"'.$container_attibutes_html.'><input '.$input_attibutes_html.'><label class="sf-label-checkbox" for="'.$input_id.'">' . $category_name . '</label><a class="eModal-post-'.$category_id.'" href="'.$category_link.'"><i class="fa fa-info-circle"></i></a>';
echo do_shortcode("[modal id='post-". $category_id ."' size='small' title='". $category_name ."']". "<div class='col-md-12'>" . $category_desc . "</div>" . "[/modal]");
}
if(isset($option->depth))
{//then we do depth calculations
$current_depth = $option->depth;
$close_li = true;
$open_child_list = false;
$close_ul = false;
$next_depth = -1;
if(isset($input_args['options'][$i+1]))
{
$next_option = $input_args['options'][$i+1];
$next_depth = $next_option->depth;
}
if($next_depth!=-1)
{
if($next_depth!=$current_depth)
{//there is a change in depth
if($next_depth>$current_depth)
{//then we need to open a child list
//and, not close the current li
$open_child_list = true;
$close_li = false;
}
else
{
$close_ul = true;
}
}
}
if($open_child_list)
{
$open_child_count++;
echo '<ul class="children">';
}
if($close_li)
{
echo "</li>";
}
if($close_ul)
{
$diff = $current_depth - $next_depth;
$open_child_count = $open_child_count - $diff;
$str_repeat = str_repeat("</ul></li>", $diff);
echo $str_repeat;
}
}
}
$str_repeat = str_repeat("</ul></li>", (int)$open_child_count);
echo $str_repeat;
?>
</ul>
<?php
$output = ob_get_clean();
return $output;
}