I am writing a small e-shop application with Symfony 2 and I need some way to store the user's shopping cart in a session. I think using a database is not a good idea.
The application will use entities like Product, Category, ShoppingCart where Product and Category are persisted into the database and users will be choosing products into their ShoppingCart.
I have found NativeSessionStorage class which is supposed to save an entity into a session. But there is no written process of implementation into an application.
Do I use this in the controller or in a separated class ShoppingCart? Could you give me a short example of NativeSessionStorage usage?
EDIT:
The question was not set correctly:
The goal is not to save all product ids into a cookie. The goal is to save only a reference for basket (filled with products) in application memory on server-side and assign proper basket to user. Is this even possible to do this in PHP?
EDIT2:
Is a better solution to use a service?
Don't know if this way is the better way to store your data temporary. You can use this to instantiate a session object :
$session = $this->get("session");
Don't forget the 'use' in your controller :
use Symfony\Component\HttpFoundation\Session;
Then, the session starts automatically when you want to set a variable like :
$session->set("product name","computer");
This is based on the use of the Session class, easy to understand. Commonly definitions :
get(string $name, mixed $default = null)
Returns an attribute.
set(string $name, mixed $value)
Sets an attribute.
has(string $name)
Checks if an attribute is defined.
Also, take a look to the other ways to store your data : Multiple SessionStorage
You can make your entity Serializable and serialize the entity object and save to session and then retrieve in other page using unserialize(). There is one caveat, for an entity that exists in the db Doctrine2 will mark the retrieved/unserialized entity as detached. You have to call $em->merge($entity); in this case.
You can save the whole object into a session with Symfony. Just use (in a controller):
$this->get('session')->set('session_name', $object);
Beware: the object needs to be serializable. Otherwise, PHP crashes when loading the session on the start_session() function.
Just implement the \Serializable interface by adding serialize() and unserialize() method, like this:
public function serialize()
{
return serialize(
[
$this->property1,
$this->property2,
]
);
}
public function unserialize($serialized)
{
$data = unserialize($serialized);
list(
$this->property1,
$this->property2,
) = $data;
}
Source: http://blog.ikvasnica.com/entry/storing-objects-into-a-session-in-symfony (my blogpost on this topic)
Related
Is it right to get Session data in a store function and store them into db?
public function store(){
...
$idgroup = Session::get('invitation_userid')];
...
}
Or need a store function always a Request Object?
public function store(Request $request){
...
$idgroup = $request('idgroup');
...
}
In both functions is of course a validation part for the input data.
Both approaches are fine, but you should use them appropriately to your use case, I prefer to use the Request data. The main difference is that if u store that inside the Session it will be available application wide, while if u send inside Request it will be available inside the method only
This depends entirely on the context of what your controller is actually named, how this data is being used and why you are not using a database session driver in the first place if you want to do this.
You could simply use the database driver for the session:
https://laravel.com/docs/5.7/session#introduction
It also depends on what your controller is named if you strictly want to follow restful routes:
https://gist.github.com/alexpchin/09939db6f81d654af06b
To answer the second question you don't always need a Request object in your store action. Most of the time you won't even see a Request object because you are simply creating an entirely new resource.
The Global Session Helper
You may also use the global session PHP function to retrieve and store data in the session. When the session helper is called with a single, string argument, it will return the value of that session key. When the helper is called with an array of key / value pairs, those values will be stored in the session:
$value = session('key');
I'm working on an application written in PHP. I decided to follow the MVC architecture.
However, as the code gets bigger and bigger, I realized that some code gets duplicated in some cases. Also, I'm still confused whether I should use static functions when quering the database or not.
Let's take an example on how I do it :
class User {
private id;
private name;
private age;
}
Now, inside this class I will write methods that operate on a single user instance (CRUD operations). On the other hand, I added general static functions to deal with multiple users like :
public static function getUsers()
The main problem that I'm facing is that I have to access fields through the results when I need to loop through users in my views. for example :
$users = User::getUsers();
// View
foreach($users as $user) {
echo $user['firstname'];
echo $user['lastname'];
}
I decided to do this because I didn't feel it's necessary to create a single user instance for all the users just to do some simple data processing like displaying their informations. But, what if I change the table fields names ? I have to go through all the code and change those fields, and this is what bothers me.
So my question is, how do you deal with database queries like that, and is it fine to use static functions when querying the database. And finally, where is it logical to store those "displaying" functions like the one I talked about ?
Your approach seems fine, howerver I would still use caching like memcached to cache values and then you can remove static.
public function getUsers() {
$users = $cacheObj->get('all_users');
if ($users === false) {
//use your query to grab users and set it to cache
$users = "FROM QUERY";
$cacheObj->set('all_users', $users);
}
return $users;
}
(M)odel (V)iew (C)ontroller is a great choice choice, but my advice is look at using a framework. The con is they can have a step learning curve, pro is it does a lot of heavy lifting. But if you want to proceed on your own fair play, it can be tough to do it yourself.
Location wise you have a choice because the model is not clearly define:
You'll hear the term "business logic" used, basically Model has everything baring views and the controllers. The controllers should be lean only moving data then returning it to the view.
You model houses DB interaction, data conversions, timezone changes, general day to day functions.
Moudle
/User
/Model
/DB or (Entities and Mapper)
/Utils
I use Zend and it uses table gateways for standard CRUD to avoid repetition.
Where you have the getUsers() method you just pass a array to it, and it becomes really reusable and you'd just have different arrays in various controller actions and it builds the queries for you from the array info.
Example:
$data = array ('id' => 26)
$userMapper->getUsers($data);
to get user 26
enter code here
$data = array ('active' => 1, 'name' => 'Darren')
$userMapper->getUsers($data);`
to get active users named Darren
I hope this help.
I have been trying to pass an array that is generated in view to controller.
Say, $abc=array(); How do I sent this array to controller, then process it and sent this array to another view?
Is it even feasible? Not getting any answer after googling! Please help.
I see no point to generate array from inside the view.
It depends how your framework passes the data between the layers.
For example the controller do pass the data to the View object.
I.e.
public function someMethodInController() {
$this->view->varName['arr_key'] = 'something';
}
But talking about view, it might not have a certain controller already instantiated (usually it's against the MVC paradigm)
So I see two major ways:
Instantiate a controller (I would not prefer this)
$controller = MyController();
$controller->abc = $abc;
Or use sessions. This way to transmit data is universal inbetween your domain, and does not care if you are using a certain pattern, or how do you transmit between layers.
$_SESSION['abc'] = $abc;
Once assigned, you can use it in the same session from each of your files.
I’m trying to better understand what the best method would be to persist data between requests in this scenario (using Zend Framework):
Say I have an Events controller and the default (index) view displays any existing Announcements (if there are any), and a link to Add a new Announcement (Both Event and Announcement are arbitrary objects). I’m trying to retrieve the eventId so I can associate the new Announcement with it when saving it to the database. Compositionally, an Event consists of 0 to many Announcements. From my limited understanding of the Zend Framework, I see two main options.
Option one: Make the URL something like ‘/event/addAnnouncement/eventId/5’, which makes retrieving the eventId easy via route/path parameters.
Option two: In the indexAction of the controller, save the eventId to a session variable, which can then be retrieved in the addAnnouncementAction of the Event controller. This way the Add Announcement link would simply be ‘/event/addAnnouncement/’.
Can anyone shed some light on which of these two ways is better, or if there is another way I’m not aware of?
As always, any help is much appreciated. Thanks.
The question to ask yourself is, how long do you need to persist the data? If you only need to save the data to pass it to the next action you can use POST or GET, the GET would pass through the url and the POST would not(typically).
The example you presented would suggest that you need to persist the data just long enough to validate, filter and process the data. So you would likely be very satisfied passing the few pieces of data around as parameters(POST or GET). This would provide the temporary persistence you need and also provide the added benefit of the data expiring as soon as a request was made that did not pass the variables.
A quick example (assume your form passes data with the POST method):
if ($this->getRequest()->isPost()) {
if ($form->isValid($this->getRequest()->getPost()){
$data = $form->getValues();//filtered values from form
$model = new Appliction_Model_DbTable_MyTable();
$model->save($data);
//but you need to pass the users name from the form to another action
//there are many tools in ZF to do this with, this is just one example
return $this->getHelper('Redirector')->gotoSimple(
'action' => 'newaction',
array('name' => $data['name'])//passed data
);
}
}
if you need to persist data for a longer period of time then the $_SESSION may come in handy. In ZF you will typically use Zend_Session_Namespace() to manipulate session data.
It's easy to use Zend_Session_Namespace, here is an example of how I often use it.
class IndexController extends Zend_Controller_Action {
protected $_session;
public function init() {
//assign the session to the property and give the namespace a name.
$this->_session = new Zend_Session_Namespace('User');
}
public function indexAction() {
//using the previous example
$form = new Application_Form_MyForm();
if ($this->getRequest()->isPost()) {
if ($form->isValid($this->getRequest()->getPost()){
$data = $form->getValues();//filtered values from form
//this time we'll add the data to the session
$this->_session->userName = $data['user'];//assign a string to the session
//we can also assign all of the form data to one session variable as an array or object
$this->_session->formData = $data;
return $this->getHelper('Redirector')->gotoSimple('action'=>'next');
}
}
$this->view->form = $form;
}
public function nextAction() {
//retrieve session variables and assign them to the view for demonstration
$this->view->userData = $this->_session->formData;//an array of values from previous actions form
$this->view->userName = $this->_session->userName;//a string value
}
}
}
any data you need to persist in your application can sent to any action, controller or module. Just remember that if you resubmit that form the information saved to those particular session variables will be over written.
There is one more option in ZF that kind of falls between passing parameters around and storing data in sessions, Zend_Registry. It's use is very similar to Zend_Session_Namespace and is often used to save configuration data in the bootstrap (but can store almost anything you need to store) and is also used by a number of internal Zend classes most notably the flashmessenger action helper.
//Bootstrap.php
protected function _initRegistry() {
//make application.ini configuration available in registry
$config = new Zend_Config($this->getOptions());
//set data in registry
Zend_Registry::set('config', $config);
}
protected function _initView() {
//Initialize view
$view = new Zend_View();
//get data from registry
$view->doctype(Zend_Registry::get('config')->resources->view->doctype);
//...truncated...
//Return it, so that it can be stored by the bootstrap
return $view;
}
I hope this helps. Pleas check out these links if you have more questions:
The ZF Request Object
Zend_Session_Namespace
Zend_Registry
Option 1 is better, although in your example this is not a POST (but it could be done with a POST).
The problems with option 2 are:
If a user had multiple windows or tabs open at the same time, relating to different events, how would you track which event ID should be used?
If a user bookmarked the add event page and came back later, the session var may not be set
Option 2 is also a little more complicated to implement, and adds a reliance on sessions.
I'm trying my best to learn MVC and cakePHP and I had a question about passing arrays to the view. Currently, I have some basic code below.
class AwarenesscampaignsController extends AppController {
public function view($id = null) {
$this->Awarenesscampaign->id = $id;
$this->set('data', $this->Awarenesscampaign->read());
}
This is what I "think" is currently happening.
AwarenesscampaignsController is set up. The view paramater requests id and matches it up with the Model, Awarenesscampaign. This matches up with the database and returns an array which is set to the variable "$data", and then the view is loaded.
My first question: is my understanding accurate?
What I would like to do is with this is to be able to pass another array, from a different model. For instance, I would like to query the table Posts (Controller: PostsController/ Model: Post).
For instance, my first attempt was to do the following inside the function:
$this->Post->find('all');
But this yields the error:
Indirect modification of overloaded property AwarenesscampaignsController::$Post has no effect [APP/Controller/AwarenesscampaignsController.php, line 20]
Additionally, I'm not sure how I would send both variables to the view.
To recap:
Was my understanding accurate?
How do I query a variable from another controller/model?
How do I sent this array to the appropriate view for that controller?
Thanks,
-M
You're on the right lines, and aren't doing it wrong per se. I would say your understanding is pretty good for a beginner.
By default Cake automatically loads a model that it thinks is directly related to the controller. So in AwarenesscampaignController, you can automatically access Awarenesscampaign (the model).
It doesn't know about any other model, though. One way you might solve this is by adding the following property to your controller:
// This has to contain ALL models you intend to use in the controller
public $uses = array('Awarenesscampaign', 'Post');
This goes at the top of the class, before you start declaring the functions. It tells Cake that you want to use other models except the 'default' one, but you have to add that one to the array too, or you'll lose access to it.
You can also use loadModel inside your action, if it's a one-off. It's then accessed the same way as you would access a model normally:
public function view($id = null) {
$this->loadModel('Post');
$posts = $this->Post->find('all');
...
}
To send this to your view, you can call set again, but you might want to change data to something more readable, and to prevent confusion:
public function view($id = null) {
...
$this->set('campaign', $this->Awarenesscampaign->read());
$this->set('posts', $this->Post->find('all'));
}
They'll be accessible as $campaign and $post respectively.
One tweak I would make, though, is to not use 'read' unless you intend to edit something. You can use findByColumnName to get the same data. Since you're using just an id, you can call findById:
$campaign = $this->Awarenesscampaign->findById($id);
There's quite a lot of magic going on there. It just means you can search for a particular value in a more short-hand format.
http://book.cakephp.org/2.0/en/models/retrieving-your-data.html
Finally, while you can access other models (as demonstrated), you can't, or generally shouldn't, try and access one controller from another. If you have code that you want to use in more than one controller, but can't go in the model, you can create Components.
http://book.cakephp.org/2.0/en/controllers/components.html#creating-a-component
The manual is fairly comprehensive. While sometimes hard to navigate, it will often have an answer to most of your questions.
http://book.cakephp.org/2.0/en/
1) Your understanding is good enough. What this is doing is basically mapping a row of database table with object. So after setting the Model id $this->Awarenesscampaign->id = $id, now Model is pointing to the row of database table that has id equals to what has been passed to view action.
2) you can query another table by calling the methods of that particular Model. If your model is somehow associated with the current Model that you are in, you can use chaining to call that Model's action. e.g. if your in Posts controller and Post Model is associated with Comment Model t get the data you can chain through.
$comments = $this->Post->Comment->find();
If however your Model of interest is not associated with current Model, there are couple of ways to perform operations of other Model. A good option is to use Class Registry. Say for example you want to use Customer Model which is not related to your current Model. In your controller you will do
$customer= ClassRegistry::init("Customer");
$customers= $customer->find();
3) to set multiple variables for the view you can set them via compact function or using associated row.
$posts = $this->Post->find();
$comments = $this->Post->Comment->find();
$this->set(compact('posts', 'comments'));
// or
$this->set('posts' => $posts, 'comments' => $comments);