allow Url::getUri() to return a URI string for routed URLs

I ran into this problem as well from a Url object that was generated with the Url::fromRoute function.

It looks like the Url::getUri() function is a straight getter function for the variable on the object. I also found a Url::toUriString() function that worked well.

Not sure what the use case is for having these two functions. I would expect the two functions to return the same thing always making them redundant.

I came here after searching for a problem with

Url::fromRoute('route.name')->getUri();

This resulted in the error "This URL has a Drupal route, so the canonical form is not a URI" as stated by the OP.

So when you want to get the Uri (path) for a specific route the code below seems to work.

Url::fromRoute('user.login')->toString();

This returns "/user/login"

‌‌Url::fromRoute('user.login')->getInternalPath();

This returns "user/login"

Why would Url:fromRoute() not use the urlGenerator to create a full Url object?

Kind regards,
Eric Mulder

I'm trying to get the URI schema from an entity.

using: $referenced_entity->toUrl()->getUri();
triggers the error "This URL has a Drupal route, so the canonical form is not a URI".

using: $referenced_entity->toUrl()->toUriString();
returns the route: route:entity.node.canonical;node=16
instead of the uri schema: entity:node/16

I've tried in different ways but it seems like I can not get the URI schema from an entity.

Some help would be appreciated.

As a solution, I propose getUri() to return the URI instead of the error: 'This URL has a Drupal route, so the canonical form is not a URI'

getUri() in https://api.drupal.org/api/drupal/core%21lib%21Drupal%21Core%21Url.php/c...

/**
   * Returns the URI value for this Url object.
   *
   * Only to be used if self::$unrouted is TRUE.
   *
   * @return string
   *   A URI not connected to a route. May be an external URL.
   *
   * @throws \UnexpectedValueException
   *   Thrown when the URI was requested for a routed URL.
   */
  public function getUri() {
    if (!$this->unrouted) {
      throw new \UnexpectedValueException('This URL has a Drupal route, so the canonical form is not a URI.');
    }
    return $this->uri;
  }

would change to something like this:

/**
   * Returns the URI value for this Url object.
   *
   * Only to be used if self::$unrouted is TRUE.
   *
   * @return string
   *   A URI not connected to a route. May be an external URL.
   *
   * @throws \UnexpectedValueException
   *   Thrown when the URI was requested for a routed URL.
   */
  public function getUri() {
    if (!$this->unrouted) {
       // Convert entity URIs to the entity scheme, if the path matches a route
       // of the form "entity.$entity_type_id.canonical".
       // @see \Drupal\Core\Url::fromEntityUri()
       $route_name = $this->getRouteName();
       foreach (array_keys($this->entityTypeManager->getDefinitions()) as $entity_type_id) {
          if ($route_name == "entity.{$entity_type_id}.canonical" && isset($url->getRouteParameters()[$entity_type_id])) {
            $uri = "entity:{$entity_type_id}/" . $url->getRouteParameters()[$entity_type_id];
            return $uri;
          }
       }
    }
    return $this->uri;
  }

Instead of updated getUri(); I would suggest to have a new public function dealing with this new functionality, I have created a patch for this; drupal core 8.9.2