How can I find which view from which controller calling an action? - model-view-controller

For example I have an "action-one" in "controller-one", if it called from views of that controller, return is different when it called from views of another controllers; So I should know which view from which controller calling an action.

It is easier to just have a flag, as an optional method parameter that you would use to specify and check in your controller.
But it is better to keep shared code in a different method if possible and have different actions for different purposes.
If what you needed was something that would not necessarily need a different action, then just pass the action name or any other identifier you wish to use and then check and do the different stuff you need to do based on their identifier.

Related

acceptable MVC parameter usage

would it be considered a valid implementation if I do not use the model for certain parameters? For example a webform posting values directly to the controller which then passes them to another class. Is it necessary to make sure that all the fields in the webform are also referenced/stored in the model?
I consider it a valid implementation, but suggest that you do this only if the parameters you want to exclude from the Model are absolutely NOT going to be used by the View (other than for confirmation of data entry in your webform), AND there is no need for the parameters to be referenced again once handled by the Controller.
Yes, it would work, strictly speaking.
However, you probably want to use the model. You don't want to create a new variable every time you run the view, which would happen if you use the controller.
I would consider it valid implementation if you decided not to use the model for certain parameters. I believe there are instances where certain fields may not relate directly to the model in question therefore giving valid reason to break those fields/parameters off from the model.

Call controller within another controller - CodeIgniter

I need to call a controller say 'faq_view' inside admin controller as the URL structure admin/faq_view like this how I can do this?
e.g:
site.com/maincontroller/function
site.com/maincontroller/othercontroller/function
Then, just redirect the page. Else if you want to just call the function, call it via AJAX.
It depends what you exactly want to do. If you want to just invoke the function, its not the right way. Controller as it defines itself controls the flow of the pages that comes on sequence. Controller is responsible to send commands to its associated view to change the view's presentation of the model.
So, if you are saying you want to call controller within another controller, that should mean you are about to redirect to another page.
Updated answer:
Just assume you have new_function on maincontroller that calls the function from othercontroller. The function does not need to be defined on othercontroller.
Add the following line on routes.php.
$routes['maincontroller/new_function'] = 'othercontroller/new_function';
Now, you can call the function of othercontroller as maincontroller/new_function.
You can always call a controller inside another controller, but this only works for calling one controller as far as I have tried. Let's say you are trying to load a controller inside a controller. You can try this:
$this->load->library('../controllers/myothercontroller');
Then do this:
$this->myothercontroller->function_name();
That's it! You can now access any function inside myothercontroller (controller) in your current controller. I hope this helps too.
Your controllers are part of the presentation layer and should not contain application logic. That means you should never need to call a controller from another controller, instead refactor your application and move the domain logic to the model layer.
Now if you have a method that you need in multiple controllers, say for example you need a template method that automatically adds your header and footer views.
If that is the case, create a base class that your controllers extend.
If you are talking about just a routing issue, then just use the routes file for that. I don't like the CI automatic routing and it should be avoided as it will result in duplicate URLs for the same resource.

yii writing a resuable code for cascade dropDownMenu

I wrote a three cascade dropDownLists that its listData are generated from the database models.
The lists are generated with an Ajax call to action in the controller based.
I want to reuse this code and to share it with more pages.
I tried to do the following:
Write it as a Custom Widget.
currently i use 'createurl' function that calls a function in the matching controller.
I cant write JavaScript since i want to use the existing db models.
In this case i need to write the action functions in an independent file - so should i write a controller? where should i place it?
Write it as a part of a module - but it seems overkill.
any suggestions, i am sure that there is a right and simple way to do it.
You could create it as a helper. A helper is just a class in the components which has no direct action in the M->C->V action flow but can be used in any controller, model, view, component, module, etc...
I would write a helper method to call it from the controller.
Another suggestion could be to extend CController to your own base controller and have your actual controllers, extend from your custom base controller. That way you can make it easily available in every controller, and then you just set some members that contain the models to use which you set in the actual controller.
If you need more help on this, find me on freenode #yii

MVC paradigm: exposing model and controller from view

I find myself needing to have a View expose its Model and Controller references. Is this the smell of bad design? Or is this considered "safe" practice?
For example: I have a list (composed of a ListView, ListController, and ListModel) and many list items (composed of a ItemView, ItemController, and ItemModel).
When I create the ItemModel, ItemView, and ItemController for each list item, I pass the ItemView instance off to the ListView. But, at some later point, my ListController needs a reference to the corresponding ItemController instance.
So, would it be more proper to pass both the ItemView and the ItemController in to ListView::addItem(), or just pass in ItemView and expose an instance method such as ItemView::getController()?
Or doesn't it matter? Is each approach equally viable? If followed to their logical conclusion, does either tactic result in an anti-pattern?
But, at some later point, my ListController needs a reference to the corresponding ItemController instance
Why? If you're decoupling your classes properly, you shouldn't need this.
Controllers almost always address a functional domain. An example of such a domain might be "Sales" or "Admin." In addition, MVC also supports the use of "Areas," which provides an additional hierarchical level of organization.
Adding references to controllers from other controllers is at cross-purposes with this organizational structure. If you need to combine functionality to make your code more DRY, ordinary refactoring will accomplish that. You can also inherit controllers from a base class containing common functionality.
In the mvc pattern the users request shall be routed to a controller, say invoicecontroller, that has actions.
Lets say the default action, Index, returns a list of invoices; the controller then creates a model with a list of invoice objects, instantiates the correct view and injects the model into the view.
Now it is the views turn to do its magic. It renders the best view it can with the data it has, which may include routes to one or more controllers.
In NO instance should the view (or model) do business logic themselves.
That said, I totally agree with Jakub. Hope that helps.
Considering you are not actually showing any code at all.
In my opinion, you should change your design. A controller is not supposed to communicate with another controller (directly), MVC dictates it: reference.
If you need to invoke a controller action from another controller, consider using delegates or composition. Instead of directly invoking the controller action.

MVC - Calling Controller Methods

My application is following the MVC design pattern. The problem I keep running into is needing to call methods inside a Controller class from outside that Controller class (ex. A View class wants to call a Controller method, or a Manager class wants to call a Controller method). Is calling Controller methods in this way allowed in MVC? If it's allowed, what's the proper way to do it?
According to the version of MVC that I am following (there seems to be so many different versions out there), the View knows of the Model, and the Controller knows of the View. Doing it this way, I can't access the controller. Here's the best site I've found and the one describing the version of MVC I'm following: http://leepoint.net/notes-java/GUI/structure/40mvc.html. The Main Program code block really shows how this works.
Thanks for any answers.
Take a closer look at this paragraph from the article you linked to:
View
This View doesn't know about the Controller, except that it provides methods for registering a Controller's listeners. Other organizations are possible (eg, the Controller's listeners are non-private variables that can be referenced by the View, the View calls the Controller to get listeners, the View calls methods in the Controller to process actions, ...).
You have the observer pattern here between the View and the Controller. MVC is not a single pattern per se but at least two combined.
One way to get your head around managing the View/Controller communication is to use events. The View fires events on certain user actions (without knowing necessarily who might handle them.) The Controller processes these events and acts accordingly.

Resources