Set session variable in laravel

问题:

I would like to set a variable in the session using laravel this way

Session::set('variableName')=$value;

but the problem is that I don't know where to put this code, 'cause I would like to set it for one time (when the guest visite the home page or any other page)? The main idea is to use a global variable to use it in all application controllers, I heared about something related to configuration variables but I'm not sure if it will be a good Idea to use config variables or only the session? Thanks

回答1:

The correct syntax for this is...

Session::set('variableName', $value);

To get the variable, you'd use...

Session::get('variableName');

If you need to set it once, I'd figure out when exactly you want it set and use Events to do it. For example, if you want to set it when someone logs in, you'd use...

Event::listen('auth.login', function()
{
    Session::set('variableName', $value);
});

回答2:

I think your question ultimately can be boiled down to this:

Where can I set a long-lived value that is accessible globally in my application?

The obvious answer is that it depends. What it depends on are a couple of factors:

• Will the value ever be different, or is it going to be the same for everybody?
• How long exactly is long-lived? (Forever? A Day? One browsing 'session'?)

Config

If the value is the same for everyone and will seldom change, the best place to probably put it is in a configuration file somewhere underneath app/config, e.g. app/config/companyname.php:

<?php
return [
    'somevalue' => 10,
];

You could access this value from anywhere in your application via Config::get('companyname.somevalue')

Session

If the value you are intending to store is going to be different for each user, the most logical place to put it is in Session. This is what you allude to in your question, but you are using incorrect syntax. The correct syntax to store a variable in Session is:

Session::put('somekey', 'somevalue');

The correct syntax to retrieve it back out later is:

Session::get('somekey');

As far as when to perform these operations, that's a little up to you. I would probably choose a route filter if on Laravel 4.x or Middleware if using Laravel 5. Below is an example of using a route filter that leverages another class to actually come up with the value:

// File: ValueMaker.php (saved in some folder that can be autoloaded)
class ValueMaker
{
    public function makeValue()
    {
        return 42;
    }
}

// File: app/filters.php is probably the best place
Route::filter('set_value', function() {
    $valueMaker = app()->make('ValueMaker');
    Session::put('somevalue', $valueMaker->makeValue());
});

// File: app/routes.php
Route::group(['before' => 'set_value'], function() {
   // Value has already been 'made' by this point. 
   return View::make('view')
       ->with('value', Session::get('somevalue'))
   ;
});

回答3:

in Laravel 5.4

use this method:

Session::put('variableName', $value);

回答4:

In Laravel 5.6, you will need to set it as

  session(['variableName'=>$value]);

To retrieve it is as simple as

$variableName = session('variableName')

回答5:

For example, To store data in the session, you will typically use the putmethod or the session helper:

// Via a request instance...
$request->session()->put('key', 'value');

or

// Via the global helper...
session(['key' => 'value']);

for retrieving an item from the session, you can use get :

$value = $request->session()->get('key', 'default value');

or global session helper :

$value = session('key', 'default value');

To determine if an item is present in the session, you may use the has method:

if ($request->session()->has('users')) {
//
}

回答6:

You can try

 Session::put('variable_Name', "Your Data Save Successfully !");  
 Session::get('variable_Name');

回答7:

To add to the above answers, ensure you define your function like this:

public function functionName(Request $request)  {
       //
}

Note the "(Request $request)", now set a session like this:

$request->session()->put('key', 'value');

And retrieve the session in this way:

$data = $request->session()->get('key');

To erase the session try this:

$request->session()->forget('key');  

or

$request->session()->flush();