Getting a menu delivered via REST - rest

Question

I am trying to get a menu via REST and I've created a new module and rest resource plugin that allows for GET on /entity/restmenu/{menu_name}.
I can successfully return this example json using this function when I hit the URL.
public function get(EntityInterface $entity) {
$result = array();
for ($i = 0; $i < 10; $i++) {
$temp = array(
'title' => 'Test ' . $i,
'href' => '#/' . $i
);
array_push($result, $temp);
}
return new ResourceResponse(json_encode($result));
}
I cannot figure out how to load the menu based on $entity. If I hit my URL (http://dang.dev:8888/entity/restmenu/main?_format=hal_json) $entity's value is 'main' which is the machine name of the main menu.
I've tried using Drupal menu tree, but I am not having luck, and debugging this thing with only JSON responses is quite difficult.
How do I get menu item titles and paths based on the menu machine name?
EDIT
Ok, sort of figured it out.
public function get($entity) {
$menu_name = $entity;
$menu_parameters = \Drupal::menuTree()->getCurrentRouteMenuTreeParameters($menu_name);
$tree = \Drupal::menuTree()->load($menu_name, $menu_parameters);
$renderable = \Drupal::menuTree()->build($tree);
$result = array();
foreach (end($renderable) as $key => $val) {
$temp = array(
'menu_item' => $val,
'route' => $key
);
array_push($result, $temp);
}
return new ResourceResponse(json_encode($result));
}
Right now that will output:
[
{
"menu_item":{
"is_expanded":false,
"is_collapsed":false,
"in_active_trail":false,
"attributes":"",
"title":"Home",
"url":{
},
"below":[
],
"original_link":{
}
},
"route":"standard.front_page"
},
{
"menu_item":{
"is_expanded":false,
"is_collapsed":false,
"in_active_trail":false,
"attributes":"",
"title":"Communities",
"url":{
},
"below":[
],
"original_link":{
}
},
"route":"menu_link_content:139d0413-dc50-4772-8200-bc6c92571fa7"
}
]
any idea why url or original_link are empty?

Answer 1

This was the correct answer:
public function get($entity) {
$menu_name = $entity;
$menu_parameters = \Drupal::menuTree()->getCurrentRouteMenuTreeParameters($menu_name);
$tree = \Drupal::menuTree()->load($menu_name, $menu_parameters);
$result = array();
foreach ($tree as $element) {
$link = $element->link;
array_push($result, array(
'title' => $link->getTitle(),
'url' => $link->getUrlObject()->getInternalPath(),
'weight' => $link->getWeight()
)
);
}
return new ResourceResponse(json_encode($result));
}