Re: Does calling model methods from elements break MVC pattern?
I'm really curious about this topic as well as it speaks to an aspect of the CakePHP Model class that has never really clicked with me. Andrea's example is perfect for explaining the point. In most MVC frameworks, when you retrieve data from storage (ram, db, file, etc), you usually get an instance of the model class itself, not a map/dictionary structure. This makes it easy to fetch calculated values, such as full_name, age, etc. In one respect, you could consider these helper functions, but I usually think of them as smart accessors - you store the minimal data necessary and calculate more common derived values on the fly (or you cache them in the rare chance it's worthwhile to do so). Andrea's suggestion (pre-calculating values in the after_find method) makes sense, but it assumes that the value is always worth calculating and storing after a lookup. (Perhaps you don't always need the value, or calculating it takes a long time). So what's the recommended convention for CakePHP for handling this stuff? Better yet, what do some of you who are veterans with the framework do? I could imagine it could be a helper class available to views where the input is the map of values. I could imagine something like QRCC suggests where its a method (static?) on the Model. Still, none of this feels right. I'm looking for something elegant and hope someone out there has already worked through this as a design issue. Thanks, skylar --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups CakePHP group. To post to this group, send email to cake-php@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/cake-php?hl=en -~--~~~~--~~--~--~---
Re: Does calling model methods from elements break MVC pattern?
First of all, i must admit that this discussion is becoming very interesting, because i often find myself thinking if the way i'm doing something with CakePHP is actually the right way. My suggestion in using the after_find was just an example of a restricted case, but I think that it's not the true correct way to do things (because there could be a lot of situations in which we cannot apply that, and there are also many cases in which that solution is not efficient at all). I think that the fact that the Model Classes are often used as nothing more than an associative array, so sometimes i don't consider those real classes; that's why i prefer to let access them only from the controller. And i even think that making some shortcut from the view to the model, could create some problems with the routing/security/etc. because in that way there are actually ACTIONS not controlled (nor performed) by a CONTROLLER. For example if you then want to make any statistic on those performed actions where can you put your code then? in the model? in the view? ..there is not the controller. Bye, Andrea On Oct 5, 9:49 am, skylar [EMAIL PROTECTED] wrote: I'm really curious about this topic as well as it speaks to an aspect of the CakePHP Model class that has never really clicked with me. Andrea's example is perfect for explaining the point. In most MVC frameworks, when you retrieve data from storage (ram, db, file, etc), you usually get an instance of the model class itself, not a map/dictionary structure. This makes it easy to fetch calculated values, such as full_name, age, etc. In one respect, you could consider these helper functions, but I usually think of them as smart accessors - you store the minimal data necessary and calculate more common derived values on the fly (or you cache them in the rare chance it's worthwhile to do so). Andrea's suggestion (pre-calculating values in the after_find method) makes sense, but it assumes that the value is always worth calculating and storing after a lookup. (Perhaps you don't always need the value, or calculating it takes a long time). So what's the recommended convention for CakePHP for handling this stuff? Better yet, what do some of you who are veterans with the framework do? I could imagine it could be a helper class available to views where the input is the map of values. I could imagine something like QRCC suggests where its a method (static?) on the Model. Still, none of this feels right. I'm looking for something elegant and hope someone out there has already worked through this as a design issue. Thanks, skylar --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups CakePHP group. To post to this group, send email to cake-php@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/cake-php?hl=en -~--~~~~--~~--~--~---
Re: Does calling model methods from elements break MVC pattern?
You are right, but the fact is that in this case we are merging more principles, and the correct thing (as far as design is concerned) in my opinion is to let the product to deal with its own responsibilities as well, but invoke those operations from the controller and not from the view. In that way you don't break nor the encapsulation principle, nor the MVC pattern, do you agree? On Oct 3, 5:31 pm, ORCC [EMAIL PROTECTED] wrote: ..the comment PERFORM BUSINESS LOGIC should immediately let you think that something is not 100% MVC ..you are performing LOGIC inside a MODEL, and not just model data handling. So, where I have to do the business logic? For example, I have a Product Object, and the product has some taxes that depends on the product itself (Its category, price, origin country, etc). Following the encapsulation principle of the object oriented programming, I think that the object to have to know how to calculate the product tax is the product itself. So I add a method Product::calculateTax(); into the class Product. Tax calculation is part of the business rules and tax value is inherent for each product, hence, I guess that the responsibility of tax calculation lays in the Product class. Why this could violate the MVC pattern? Or is the product controller who has to know how to calculate the product's tax? --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups CakePHP group. To post to this group, send email to cake-php@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/cake-php?hl=en -~--~~~~--~~--~--~---
Re: Does calling model methods from elements break MVC pattern?
hi everybody,
I'm not a MVC guru,but in my opinion, the fact
that a view can import something and invoke
actions not performed by a controller, but from
a model, breaks somehow the MVC pattern.
Maybe if you need some action to manipulate data
of a model before display them, you should use
the afterfind of the model.
For example if you are handling Users, and you want
the full name with initials, but in the DB you have
name,surname and initials, you should put in after find
method something that bind together the 3 fields
and create a new key $user['User']['fullname'].
Moreover since in your example you wrote this:
class Product extends AppModel {
//... all attributes and methods
function performSomeProductCalculation () {
//perform business logic
return $result;
}
}
..the comment PERFORM BUSINESS LOGIC should immediately
let you think that something is not 100% MVC ..you are
performing LOGIC inside a MODEL, and not just model data
handling.
Anyway i don't want say that's wrong, but only that's not
100% MVC and in this way answering to your question.
Bye!!
Andrea
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Re: Does calling model methods from elements break MVC pattern?
hi everybody,
I'm not a MVC guru,but in my opinion, the fact
that a view can import something and invoke
actions not performed by a controller, but from
a model, breaks somehow the MVC pattern.
Maybe if you need some action to manipulate data
of a model before display them, you should use
the afterfind of the model.
For example if you are handling Users, and you want
the full name with initials, but in the DB you have
name,surname and initials, you should put in after find
method something that bind together the 3 fields
and create a new key $user['User']['fullname'].
Moreover since in your example you wrote this:
class Product extends AppModel {
//... all attributes and methods
function performSomeProductCalculation () {
//perform business logic
return $result;
}
}
..the comment PERFORM BUSINESS LOGIC should immediately
let you think that something is not 100% MVC ..you are
performing LOGIC inside a MODEL, and not just model data
handling.
Anyway i don't want say that's wrong, but only that's not
100% MVC and in this way answering to your question.
Bye!!
Andrea
--~--~-~--~~~---~--~~
You received this message because you are subscribed to the Google Groups
CakePHP group.
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Re: Does calling model methods from elements break MVC pattern?
..the comment PERFORM BUSINESS LOGIC should immediately let you think that something is not 100% MVC ..you are performing LOGIC inside a MODEL, and not just model data handling. So, where I have to do the business logic? For example, I have a Product Object, and the product has some taxes that depends on the product itself (Its category, price, origin country, etc). Following the encapsulation principle of the object oriented programming, I think that the object to have to know how to calculate the product tax is the product itself. So I add a method Product::calculateTax(); into the class Product. Tax calculation is part of the business rules and tax value is inherent for each product, hence, I guess that the responsibility of tax calculation lays in the Product class. Why this could violate the MVC pattern? Or is the product controller who has to know how to calculate the product's tax? --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups CakePHP group. To post to this group, send email to cake-php@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/cake-php?hl=en -~--~~~~--~~--~--~---
Does calling model methods from elements break MVC pattern?
It is a question about MVC pattern in cakephp.
I have a calculated value that I want to display in many views, so I
decided to create an element. The business logic has to be performed
in the model, i.e:
models/product.php
class Product extends AppModel {
//... all attributes and methods
function performSomeProductCalculation () {
//perform business logic
return $result;
}
}
There are two options to create an element that renders the result
returned by the above method:
- Option 1: Call the model method directly from element:
views/elements/foo.ctp
?php
App::import('Model','Product');
$p = New Product();
?
div class=result
The result is ?php echo $p-performSomeProductCalculation() ?
/div
- Option 2: Create a controller method for rendering the result, and
call that method in the element via requestAction
controllers/products_controller.php
class ProductsController extends AppController {
//... all attributes and method
function my_result() {
return $this-Product-performSomeProductCalculation();
}
}
views/elements/foo.ctp
?php
$r = $this-requestAction('/products/my_result');
?
div class=result
The result is ?php echo $r; ?
/div
Wich options is the correct one in order to respect 100% the MVC
pattern? ? ?
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Re: Does calling model methods from elements break MVC pattern?
Does calling model methods from elements break MVC pattern?
yep.
Views are for laying out stuff. controllers for pasing data to view and
models for obtaining data.
If your model passes the data to the controller so that the controller has
to process the data as little as possible for the view
http://gluei.com/blog/view/cakephp-best-practices-fat-models-and-skinny-controllers
http://cakebaker.42dh.com/2008/01/19/fat-models-and-how-they-change-how-you-use-the-model-class/
There are some performance drawbacks with using requestaction like that.
Mark Story provides details of a solution around requestaction (though this
method also has its critics)
http://mark-story.com/Posts/view/reducing-requestaction-use-in-your-cakephp-sites-with-fat-models
hth -S
2008/10/2 ORCC [EMAIL PROTECTED]
It is a question about MVC pattern in cakephp.
I have a calculated value that I want to display in many views, so I
decided to create an element. The business logic has to be performed
in the model, i.e:
models/product.php
class Product extends AppModel {
//... all attributes and methods
function performSomeProductCalculation () {
//perform business logic
return $result;
}
}
There are two options to create an element that renders the result
returned by the above method:
- Option 1: Call the model method directly from element:
views/elements/foo.ctp
?php
App::import('Model','Product');
$p = New Product();
?
div class=result
The result is ?php echo $p-performSomeProductCalculation() ?
/div
- Option 2: Create a controller method for rendering the result, and
call that method in the element via requestAction
controllers/products_controller.php
class ProductsController extends AppController {
//... all attributes and method
function my_result() {
return $this-Product-performSomeProductCalculation();
}
}
views/elements/foo.ctp
?php
$r = $this-requestAction('/products/my_result');
?
div class=result
The result is ?php echo $r; ?
/div
Wich options is the correct one in order to respect 100% the MVC
pattern? ? ?
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Re: Does calling model methods from elements break MVC pattern?
Mark Story provides details of a solution around requestaction (though this method also has its critics) http://mark-story.com/Posts/view/reducing-requestaction-use-in-your-cakephp-sites-with-fat-models yea but since it is MarkStory Day you can't critique him right now. So using that method right now should be perfect ;) --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups CakePHP group. To post to this group, send email to cake-php@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/cake-php?hl=en -~--~~~~--~~--~--~---
Re: Does calling model methods from elements break MVC pattern?
Ok, that means that I would consider to pass parameters to my elements (parameters calculated inside the controller) to avoid a requestAction call, doesn't it? --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups CakePHP group. To post to this group, send email to cake-php@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/cake-php?hl=en -~--~~~~--~~--~--~---
