I'm building a simple login system for the CI based site and I I'm unsure of where to place my function:
is_logged_in()
// check if session logged in stuff exists
// if not check for cookie and reset from that
// return true or false
To start with I need to call this from some public pages so they they can display 'You're logged in as [blah]. Continue to members area'.
Would it make sense to put this in my login model, call it from my controller(s) and then simply pass the result (logged_in: true/false) to my views?
Mostly.
This might be a Model or it might be a Library issue. The question becomes how you are storing whether they are logged in. Personally, I generally put it in a Library which calls a specific Model, it seems less elegant at first, but realistically, I don't want my Model to know anything about my $_SESSION or my $this->session, one of which would be necessary if I wanted to have a good authentication system.
As to how to communicate with the view, there are a couple of ways:
Have it as a special variable passed to the view:
Bonus: It is the most obvious.
Detriment: You will need to place it into every single call to view. This means either you override your loader or you update all of your controls (might be gross).
Have it defined as a constant:
Bonus:By far the easiest if you have logic in the view.
Detriment:Constants are rarely the way to go, they are hard to debug, and it is not a very CodeIgniter way of doing things.
Have a helper function (literally a "helper" function)
Bonus:Universally accessible value which is relatively easy to debug.
Detriment:Requires a helper to know about a Library and/or Model (this is actually true of the built in form_helper, but it still opens up a proverbial can of worms) and it will probably be a one-function helper file.
Conditionally include a view from the controller
Bonus:It removes all logic from your view.
Detriment:You still need to make your controllers aware of the logic.
Personally, I am most likely to use #'s 3 & 4, but each has its advantages.
Related
In a codeigniter project i have to do some set of stuff in one than one controller.
I code all that stuff in a function and now i need to call whenever necessary.
i think Writing this function in more than one controller is not good.
i have 2 options,
create a helper and write these function in that and include the helper in necessary controllers.
Since i have extended CI base controller (My_Controller) and most of my controllers are extended that controller, i can write this function to my base controller also.
I have confused which one is better, right way?
Which one will speed up the process?
Is the second way slows the site?
They are identical for all intents and purposes.
Using a helper allows you to make the code portable, so you can use it in other projects, or to be called from anywhere in the code base, in the case of a formatting function for example
If you were planning to put it in a controller, then MY_Controller is best bet
Just to help you on you endeavor what i do is: (this is just me)
If i need to use something in the views, i use a helper a custom one or built in.
If i want to do something on a controller that other controller will be using too and don't want it to mess up or crowd my controller i use a library (pretty much you can use a helper but i chose to use a library)
If i want to load lets say a method, to affect Globally or some of the controller i use the base controller. (you could also use helper or library)
The key is you are not restricted to one, choose the best that suits you, as the saying goes, there are many ways to skin a cat, but please don't skin a cat..
So, I like CakePHP and use it lots. When 2.0 came out, I was pleased to see the AuthComponent be made available throughout your whole application as a static class, which makes lots of things much easier - i.e. you no longer have to pass user data as an argument to model methods.
Recently on a project, I have perceived the need to access methods of the SessionComponent from a Model. Specifically, when a user logs in, some checks are performed to see if the user has a valid subscription to the site. This is all done in the model. If the user no longer has a valid subscription, there are a few reasons why that might be. It seems easiest to return false from the model, and at the same time set a flash message giving the reason for the expired subscription. Rather than return an array something like this:
array('status' => 0, 'message' => 'You\'re not welcome here anymore')
which needs interpreting in the controller.
There are other times I have wanted to deal with sessions in models, but this is the example that came to mind.
So, I'd like to know, am I right in wanting to access the SessionComponent in models? Should I just use $_SESSION directly when I have this need? Or am I doing things wrong - are there better ways to code?
you can always use
CakeSession::read()
anywhere in your application. so also in the model.
see previous posts like Reading a session variable inside a behavior in cakephp 2
but be adviced, that you should try to avoid it if possible.
models are supposed to be as stateless as possible - mixing them with sessions makes that more and more blurry.
According to CakePHP cookbook:
Usage of the $_SESSION is generally avoided in CakePHP, and instead
usage of the Session classes is preferred.
There are several different configurations where you can store session data, f.ex. in the database. So, by using CakeSession changes to session configuration will not affect every place where you access session data.
I would advice not to use SessionComponent from the model. Better pass parameters to the model with necessary data. Take a look at Understanding Model-View-Controller.
Passing session control to the Model violates MVC. You should use the model to make the decisions and the controller to reflect those decisions to the application. In a correct MVC enviroment the Model won't even know you are using sessions much less manipulating it.
Also, using the $_SESSION var violates the framework encapsulation. If you find yourself needing to do that, yes, you went wrong somewhere.
You can write and read data in session in model by using Authcomponent and session
App::uses('AuthComponent', 'Controller/Component');
App::import('Component', 'Session');
and you can write and read data using following functions
CakeSession::write('Auth.User.id', '1');
debug(CakeSession::read());
I have this idea of generating an array of user-links that will depend on user-roles.
The user can be a student or an admin.
What I have in mind is use a foreach loop to generate a list of links that is only available for certain users.
My problem is, I created a helper class called Navigation, but I am so certain that I MUST NOT hard-code the links in there, instead I want that helper class to just read an object sent from somewhere, and then will return the desired navigation array to a page.
Follow up questions, where do you think should i keep the links that will only be available for students, for admins. Should i just keep them in a text-file?
or if it is possible to create a controller that passes an array of links, for example
a method in nav_controller class -> studentLinks(){} that will send an array of links to the helper class, the the helper class will then send it to the view..
Sorry if I'm quite crazy at explaining. Do you have any related resources?
From your description it seems that you are building some education-related system. It would make sense to create implementation in such way, that you can later expand the project. Seems reasonable to expect addition of "lectors" as a role later.
Then again .. I am not sure how extensive your knowledge about MVC design pattern is.
That said, in this situation I would consider two ways to solve this:
View requests current user's status from model layer and, based on the response, requests additional data. Then view uses either admin or user templates and creates the response.
You can either hardcode the specific navigation items in the templates, from which you build the response, or the lit of available navigation items can be a part of the additional information that you requested from model layer.
The downside for this method is, that every time you need, when you need to add another group, you will have to rewrite some (if not all) view classes.
Wrap the structures from model layer in a containment object (the basis of implementation available in this post), which would let you restrict, what data is returned.
When using this approach, the views aways request all the available information from model layer, but some of it will return null, in which case the template would not be applied. To implement this, the list of available navigation items would have to be provided by model layer.
P.S. As you might have noticed from this description, view is not a template and model is not a class.
It really depends on what you're already using and the scale of your project. If you're using a db - stick it there. If you're using xml/json/yaml/whatever - store it in a file with corresponding format. If you have neither - hardcode it. What I mean - avoid using multiple technologies to store data. Also, if the links won't be updated frequently and the users won't be able to customize them I'd hardcode them. There's no point in creating something very complex for the sake of dynamics if the app will be mostly static.
Note that this question doesn't quite fit in stackoverflow. programmers.stackexchange.com would probably be a better fit
I am new to MVC, CodeIginter. Instead of getting things easy, it needs lot of code to be written for a simple application. These are might be happening becouse I am new. So I have few confusions about this thing. Any kind of help is appreciated.
1) Methods are written in one controller can not be accessed in another controller classes. I have to write a new function for the same functionality.
2) To create website administration panel (back-end) in none mvc panel, we usually create it in a new folder. Is this thing possible in CodeIgniter? If not what about the admin (back-end)??
Let's try to clear some of your doubts about this.
1) Calling a controller's method from another controller is not possible, and it's whtouth meaning by the way.
A controller is supposed to get an action from the URL (which is routed by CI to the right controller for the task) and, based on that, decide which Model and which model's method needs be called to elaborate the data requested.
The model, then, hands back the result of this elaboration to the controller, which , in turns, decides to which view pass this results.
The view, eventually, is structured to get those datas and display them.
SO, as you can see, calling a controllers' method from another controller is nonsense, it would be like going to a page and finding another one instead; if you want to pass to another controller the request...well, there's the redirect for that.
If you find out you have the same functionalities in several moment, think twice:
What is a funcionality? Do you mean somehtin like "display posts" in controller "archive" and "display posts" in controller "news" ? they're hardly the same functionality; they can maybe share views, or models, but that's it.
For functions that doesn't relate to URLs, but involve some further elaboration (which might be wrong to do in Models) and are nonetheless called in a controller, you have library instead. Think at the "form_validation" library, which is called in a controller's method, but has its own peculiar (and encapsulated) functionalies. Ora a "session" library, or an "authentication" library
2) To create an admin panel the easiest thing is: create an "admin" controller (which is accesible then to www.mysite.com/index.php/admin), and put all the administration actions there, in its methods: create_page(), edit_page(), manage_users(), whatever.
In order to avoid people accessing it freely you need to build an authentication system, which, in its simplest and barabone strucutre, might be a check of wheter a session is set or not (maybe a check done at __construct() time).
But you can find nice Auth libraries out there already made, such as Ion Auth or Tank Auth (the 2 most popular to my knowledge)
Hope things are a bit clearer now. See also Interstellar_Coder's comment at this answer if you're interested in the modular HMVC approach.
1) Methods are written in one controller can not be accessed in another controller classes. I have to write a new function for the same functionality.
What's the functionality about? Perhaps you should write a library/helper instead, controller's logic should be limited to request flow or something else but not too complicated. For that, put the functionality in the model, or if more general, in library/helper.
2) To create website administration panel (back-end) in none mvc panel, we usually create it in a new folder. Is this thing possible in CodeIgniter? If not what about the admin (back-end)??
I don't get it, could you elaborate more?
The text is quite long, the question is actually simple and written in bold. The other text is only for trying to explain the problem.
I have recently started to use CodeIgniter for developing my website. Currently, I'm writing a side menu where you can filter the items showed in the view (basic e-commerce functionality).
The idea I had was to have an array in my Shop-controller where I store my filtering values which are passed to and from my filterview, so the filter menu kan handle several types of filters.
The problem is that it seems like the constructor of the controller is run each time the controller is called. I thought that the controller was constructed only once when the user enters the website. I'm pretty new at website devlopment and am mainly a C++-guy, so this seems a bit strange for me.
My question is pretty simple actually: Is it true that the controller instance is created at each call to a controller function? Otherwise, what am I doing wrong to cause the controller instance to be reinstantiated at each controller call...
I hope that my question is not too fuzzy. It is important for me to understand the lifecycle behaviour of CodeIgniter to be able to find a simple solution for this. I would like to avoid using $_SESSION, because I would like to use a OOP like solution.
Is it true that the controller
instance is created at each call to a
controller function? Otherwise, what
am I doing wrong to cause the
controller instance to be
reinstantiated at each controller
call..
Yes, the controller instance is re-instantiated every time you make a call to that controller. In CodeIgniter, there is no such thing as a persistent instance of your controller for each user interacting with your application (unlike single-user apps built in C++). What you do have is session management, where you use Session variables to store data persistent to that particular session between the user's browser and your web server (more). Another way to do this is by using cookies. I personally prefer session over cookies.
There is no harm in using $_SESSION for the purpose of your filter, and it is not against OOP principles. What matters is how you use the data stored in your Session variable once your controller instance has loaded ( that's where the OOP concepts come into play).
Shivaas, the same answer can by safely used with models? What about autoloading models? I mean, autoloading it's just a way to avoid typing $this->load->model('the_model') when needed? There's no way to use singleton pattern without recurring to use session/database?
private $instance;
function init_model() {
if ($this->instance === NULL) {
$this->instance = array();
}
return $this->instance;
}
Once init_model exits, the class instance is destroyed so $instance will be always initialized to a new array()?