找不到Laravel 4类和名称空间

Question

In a Laravel 4 site I have installed a tag cloud library. In this library I wish to edit the return line of a function (I have simplified it here):

return "<span>
      {$Variable}
    </span>";

and make the $variable a link:

return "<span>
       <a href='".Request::url()."/myroute/'>
         {$variable}
       </a>
    </span>";

When I try to run the page I get the error:

Class 'Arg\Tagcloud\Request' not found 

I thought that it might mean that the Request class is not visible within the tagcloud class and it has to do with namespaces.

On top of the tagcloud class file there are these lines:

<?php namespace Arg\Tagcloud;
use Illuminate\Support\Facades\Facade;

I have found this page (a list of laravel namespaces) http://laravel.com/api/index.html

and I have used

    use Illuminate\Routing;

or

     use Illuminate;

I added them just below the above first two 'use' statements but I get the same error (class not found). Is it a matter of finding the right namespace or something else? Can anyone help? Thanks.

EDIT: I found this way of doing what I wanted without using Request::url():

        return "<span>
       <a href='/mysitename/public/myroute/{$variable}'>
         {$variable}
       </a>
    </span>";

Answer 1

Whenever you put your class in a namespace, any other class that you reference in that class assumes that it is also in that same namespace unless you tell it otherwise.

So, since you set your namespace to Arg\\Tagcloud when you directly reference Request::url() , PHP thinks that you're telling it to use the Request class inside the Arg\\Tagcloud namespace.

There's two solutions to this:

Solution 1

Add a \\ in front of Request to tell PHP to use the global namespace, not the Arg\\Tagcloud namespace.

eg, <a href='".\\Request::url()."/myroute/'>

Solution 2

use the class.

Just add use Request to the top of your class (under your namespace), this will let PHP know that you want to use this class, but it doesn't belong in the current namespace.

eg,

<?php namespace Arg\Tagcloud;

use Request;

Answer 2

When I try to run the page I get the error:

Class 'Arg\\Tagcloud\\Request' not found

It's because you are using the Request class from Arg\\Tagcloud namespace and when you use Request::someMethod() framework things that Request class is under same namespace which is:

Arg\Tagcloud\Request

But, actually, Request class is under, Illuminate\\Http namespace and that's why the error is being occurred. To overcome this problem you may use something like this:

\Request::someMethod();

Or you may use following at the top of your class:

use \Request;

You don't need to use use Illuminate\\Request; because Request facade class is available in the global namespace (as an alias) which will resolve the Illuminate\\Http\\Request class. So, you can directly use Request::someMethod() in your code.