Error running make:request on laravel 5

Question

When running the example code on the laravel docs php artisan make:request StoreBlogPostRequest to create a new validation controller, I get the following error

[RuntimeException]                       
Unable to detect application namespace.  

I'm not sure what's wrong, I've done some searching, but nothing really explains this error. Any ideas?

Answer 1

In Laravel 5, an "application" is a collection of PHP files under a single namespace, stored in the folder app/

By default, and in most of the Laravel 5 sample code from the docs, this namespace is App\. For example, one controller in your application might look like this.

namespace App\Http\Controller;
class MyController
{
    //...
}

When Laravel generates code (i.e. when you use the make:request command), it needs to know what this application namespace is (it's possible to change the namespace with the artisan app:name command). For some reason, in your system, Laravel 5 can't detect the namespace.

If you look at the section of Laravel 5 core code that detects the namespace

#File: vendor/laravel/framework/src/Illuminate/Console/AppNamespaceDetectorTrait.php
protected function getAppNamespace()
{
    $composer = json_decode(file_get_contents(base_path().'/composer.json'), true);

    foreach ((array) data_get($composer, 'autoload.psr-4') as $namespace => $path)
    {
        foreach ((array) $path as $pathChoice)
        {
            if (realpath(app_path()) == realpath(base_path().'/'.$pathChoice)) return $namespace;
        }
    }

    throw new RuntimeException("Unable to detect application namespace.");
}

You'll see that Laravel detects the namespace by looking at your composer.json file, and looking for thefirst valid psr-4 namespace.

My guess is your composer.json file is missing the namespace

"autoload": {
    "classmap": [
        "database"
    ],
    "psr-4": {
        "App\\": "app/"
    }
},

Add that back in, and you'll be good to go.