What do you have in your model classes. Generally if i use any framework or any library (Zend Framework) , my classes only have variable which is table name . I know that in complicated applications models have lots of thing to do , so i want to know what these jobs are.
Maybe instead of using library`s general select function ,you create special functions to get data from database ( getUserById() ) . To sum up , which parts of the process should go in to model layer.
For example thing about general user processes .So in registration process where should we check email is acceptable or not . This is example just explain what do you do in your model layer.
This question may seem as an abstract question because of my english , but it is not . If you can edit it please improve it . The purpose of this question is better understanding of mvc pattern
Well, in general, models should do the main work regarding your business layer. So, if you have a pretty complex query using (and combining) the accessor functions of the database layer (thus, your model), you should instead write an extra function for that query in your model class. Makes it much easier to change the implementation of your model (e.g. database-table-wise).
EDIT: To answer your other question: validating an e-mail should happen in the controller, usually using some kind of component, utility class or library...
Related
I'm learning Laravel and I'm watching many tutorials, but I dont really get it, what's the difference between the controller and model, because you can put in both a function.
Controllers in Laravel are used to determine how to handle http requests.
When you have anything to do with the DB, its better to place those function in the model, and call them from the controller.
In clear terms:
Model performs all operations on data from DB.
Controller call necessary model methods and ready the data.
View take care of displaying the data.
I hope this is clear enough.
You will be familiar with all of this soon.
model methods is for relationships mainly , or to make some thing for every object of this model (database table) every column in db is an object and every table is a model.
but in controller you set your app functionality that you want , and its an intermediator between model and view .
i hop this makes you good in this point.
good luck
You can write functions anywhere, you are perfectly right.
But is not an efficient way to do things.
The answers for those questions can be easily find out. Search about MVC pattern. In few words, remember brief:
MODEL => working with relational databases / storing the data
CONTROLLER => working with the logic(taking inputs, calculus etc) / general functionalities
Combining them is more efficient than working with those together, that is the reason why using a pattern is more great than writing code in a old style mode reinventing the wheel again.
I'm trying to understand the MVC pattern in Phalcon.
In my current application I only need ONE template file for each table. The template contains the datagrid, the SQL statement for the SELECT, the form, add/edit/delete-buttons, a search box and all things necessary to interact with the database, like connection information (of course using includes as much as possible to prevent duplicate code). (I wrote my own complex framework, which converts xml-templates into a complete HTML-page, including all generated Javascript-code and CSS, without any PHP needed for the business logic. Instead of having specific PHP classes for each table in the database, I only use standard operation-scripts and database-classes that can do everything). I'm trying to comply more with web standards though, so I'm investigating alternatives.
I tried the INVO example of Phalcon and noticed that the Companies-page needs a Companies model, a CompaniesController, a CompaniesForm and 4 different views. To me, compared to my single file template now, having so many different files is too confusing.
I agree that separating the presentation from the business logic makes sense, but I can't really understand why the model and controller need to be in separate classes. This only seems to make things more complicated. And it seems many people already are having trouble deciding what should be in the model and what should be in the controller anyway. For example validation sometimes is put in the model if it requires business logic, but otherwise in the controller, which seems quite complex.
I work in a small team only, so 'separation of concerns' (apart from the presentation and business logic) is not really the most important thing for us.
If I decide not to use separate model and controller classes,
what problems could I expect?
Phalcon's Phalcon\Mvc\Model class, which your models are supposed to extend, is designed to provide an object-oriented way of interacting with the database. For example, if your table is Shopping_Cart then you'd name your class ShoppingCart. If your table has a column "id" then you'd define a property in your class public $id;.
Phalcon also gives you methods like initialize() and beforeValidationOnCreate(). I will admit these methods can be very confusing regarding how they work and when they're ran and why you'd ever want to call it in the first place.
The initialize() is quite self-explanatory and is called whenever your class is initiated. Here you can do things like setSource if your table is named differently than your class or call methods like belongsTo and hasMany to define its relationship with other tables.
Relationship are useful since it makes it easy to do something like search for a product in a user's cart, then using the id, you'd get a reference to the Accounts table and finally grab the username of the seller of the item in the buyer's cart.
I mean, sure, you could do separate queries for this kind of stuff, but if you define the table relationships in the very beginning, why not?
In terms of what's the point of defining a dedicated model for each table in the database, you can define your own custom methods for managing the model. For example you might want to define a public function updateItemsInCart($productId,$quantity) method in your ShoppingCart class. Then the idea is whenever you need to interact with the ShoppingCart, you simply call this method and let the Model worry about the business logic. This is instead of writing some complex update query which would also work.
Yes, you can put this kind of stuff in your controller. But there's also a DRY (Don't Repeat Yourself) principle. The purpose of MVC is separation of concerns. So why follow MVC in the first place if you don't want a dedicated Models section? Well, perhaps you don't need one. Not every application requires a model. For example this code doesn't use any: https://github.com/phalcon/blog
Personally, after using Phalcon's Model structure for a while, I've started disliking their 1-tier approach to Models. I prefer multi-tier models more in the direction of entities, services, and repositories. You can find such code over here:
https://github.com/phalcon/mvc/tree/master/multiple-service-layer-model/apps/models
But such can become overkill very quickly and hard to manage due to using too much abstraction. A solution somewhere between the two is usually feasible.
But honestly, there's nothing wrong with using Phalcon's built-in database adapter for your queries. If you come across a query very difficult to write, nobody said that every one of your models needs to extend Phalcon\Mvc\Model. It's still perfectly sound logic to write something like:
$pdo = \Phalcon\DI::getDefault()->getDb()->prepare($sql);
foreach($params as $key => &$val)
{
$pdo->bindParam($key,$val);
}
$pdo->setFetchMode(PDO::FETCH_OBJ);
$pdo->execute();
$results=$pdo->fetchAll();
The models are very flexible, there's no "best" way to arrange them. The "whatever works" approach is fine. As well as the "I want my models to have a method for each operation I could possibly ever want".
I will admit that the invo and vokuro half-functional examples (built for demo purposes only) aren't so great for picking up good model designing habits. I'd advise finding a piece of software which is actually used in a serious manner, like the code for the forums: https://github.com/phalcon/forum/tree/master/app/models
Phalcon is still rather new of a framework to find good role models out there.
As you mention, regarding having all the models in one file, this is perfectly fine. Do note, as mentioned before, using setSource within initialize, you can name your classes differently than the table they're working on. You can also take advantage of namespaces and have the classes match the table names. You can take this a step further and create a single class for creating all your tables dynamically using setSource. That's assuming you want to use Phalcon's database adapter. There's nothing wrong with writing your own code on top of PDO or using another framework's database adapter out there.
As you say, separation of concerns isn't so important to you on a small team, so you can get away without a models directory. If it's any help, you could use something like what I wrote for your database adapter: http://pastie.org/10631358
then you'd toss that in your app/library directory. Load the component in your config like so:
$di->set('easySQL', function(){
return new EasySQL();
});
Then in your Basemodel you'd put:
public function easyQuery($sql,$params=array())
{
return $this->di->getEasySQL()->prepare($sql,$params)->execute()->fetchAll();
}
Finally, from a model, you can do something as simple as:
$this->easyQuery($sqlString,array(':id'=>$id));
Or define the function globally so your controllers can also use it, etc.
There's other ways to do it. Hopefully my "EasySQL" component brings you closer to your goal. Depending on your needs, maybe my "EasySQL" component is just the long way of writing:
$query = new \Phalcon\Mvc\Model\Query($sql, $di);
$matches=$query->execute($params);
If not, perhaps you're looking for something more in the direction of
$matches=MyModel::query()->where(...)->orderBy(...)->limit(...)->execute();
Which is perfectly fine.
Model, View and Controller were designed to separate each process.
Not just Phalcon uses this kind of approach, almost PHP Frameworks today uses that approach.
The Model should be the place where you're saving or updating things, it should not rely on other components but the database table itself (ONLY!), and you're just passing some boolean(if CRUD is done) or a database record query.
You could do that using your Controller, however if you'll be creating multiple controllers and you're doing the same process, it is much better to use 1 function from your model to call and to pass-in your data.
Also, Controllers supposed to be the script in the middle, it should be the one to dispatch every request, when saving records, when you need to use Model, if you need things to queue, you need to call some events, and lastly to respond using json response or showing your template adapter (volt).
We've shorten the word M-V-C, but in reality, we're processing these:
HTTP Request -> Services Loaded (including error handlers) -> The Router -> (Route Parser) -> (Dispatch to specified Controller) -> The Controller -> (Respond using JSON or Template Adapter | Call a Model | Call ACL | Call Event | Queue | API Request | etc....) -> end.
A quick question this time about the M in Mvc.(using codeigniter, but the question is general)
Suppose I have several models that are responsible for accessing several tables in my database, Is it frowned upon making one flexible model that can deal with everything?
specifically in php-codeigniter, for example:
$this->MY_model->getByID($table,$ID)
So this example code can be used to get by ID of any table I want thus saving me time and I'm able to reuse most of my model code.
This of course can be expanded further
$this->MY_model->update($table,$info) as an example.
So my question is, If all of the above is okay, Where is the 'limit' to such operations? Naturally we wouldn't want something really specific in this type of model, like this method:
$this->MY_model->getAllActiveUsers()
My basic approach is this:
Any method that can be used in more than one table should be used in the extended model.
Any method that should be used in only one table, should be in it's own model.
Just to be clear i'm not looking for an opinion, But rather wondering what's the standard approach to these issues.(for example, imagine an application with 50 models, should CRUD be written for all 50 of them?)
Thanks in advance!
What you are mulling about is pretty standard operation for most Codeigniter developers. If you are going to be doing a lot of CRUD in the DB, then it makes sense to add a set of generic CRUD methods to your base MY_model and then extend it. If you do a search on Google...you'll likely get results for 100s of people who have setup their own base models including CRUD and other common methods used by most Codeigniter projects...here are just a couple:
https://github.com/jamierumbelow/codeigniter-base-model
https://github.com/jenssegers/CodeIgniter-My-Model
should CRUD be written for all 50 of them?
No. You would extend your base model and use it's generic CRUD methods where they make sense and just override certain properties (table name). Then, if you needed something more specific you could create additional, more granular methods in your new model as you suggested.
My problem is in somewhere between model and controller.Everything works perfect for me when I use MVC just for crud (create, read, update, delete).I have separate models for each database table .I access these models from controller , to crud them . For example , in contacts application,I have actions (create, read, update, delete) in controller(contact) to use model's (contact) methods (create, read, update, delete).
The problem starts when I try to do something more complicated. There are some complex processes which I do not know where should I put them.
For example , in registering user process. I can not just finish this process in user model because , I have to use other models too (sending mails , creating other records for user via other models) and do lots of complex validations via other models.
For example , in some complex searching processes , I have to access lots of models (articles, videos, images etc.)
Or, sometimes , I have to use apis to decide what I will do next or which database model I will use to record data
So where is the place to do this complicated processes. I do not want to do them in controllers , Because sometimes I should use these processes in other controllers too. And I do not want to put these process in models because , I use models as database access layers .May be I am wrong,I want to know . Thank you for your answer .
Just a short comment (no solution) AFAIK that is an eternal question - MVC is just a pattern, and as such, is in theory implementable cleanly. In practise, due to limitations set by available tools (such as programming language library contents and UI component interface design..) you have to make local decisions. The important thing is that you aim to separate these...and not have everything in one mess. I take my comment off the air and am left to see if someone has a "final solution".
For simple tasks I would write action helpers (e.g. sendNewsletter).
For sophistocated tasks I woud create services (eg. email, auth etc.).
In MVC, you should place those things in the model (for reuse reasons for one).
However, in HVMC, you could place them wherever (such as in a controller) and call the controllers from within your application.
I would make your controllers simple.
In many ways the model allows you to offload a lot of the complexity that would otherwise occlude your controller code. Its this division of complexity which will make your code more easily understood, and easier to maintain.
personally I try to keep my models resembling real world objects, not databases tables or rows. It makes it much easier if you have made things speak in more readable terms. A single real world object might involve 5 or 6 database tables... And it would be a rather large hassle to speak with 5 or 6 models, when all you want to do is turn on a switch, or pick a flower, or paint an icon, or send a message.
What's wrong with a controller using multiple models? Isn't the point of MVC to make the model reusable? In your first scenario, it's perfectly fine to send emails and manipulate other model objects from wherever the "register user" controller code is.
In regard to your second scenario, why can't SearchController use ArticleModel, ImageModel and VideoModel? It's fine to have a controller without a model. SearchController doesn't need a SearchModel class, it just uses the other model classes.
I'm trying not to get into a rant about MVC in web apps, but basically, IMHO the controller is just a high-level list of steps to complete an operation. As a rough example, the "register user" controller code should do each of the following steps in roughly one or two lines of code:
Validate the input
If not valid, redisplay the form with an error
Create the new UserModel object from the form input
Insert the new UserModel object into the database
Create/edit whatever other model objects are necessary
Send off an email to the new user
Display a "registration successful" page
How those steps are coded largely depends on whatever framework/architecture you're using.
Keep your controllers clean. For backend processing use Manager classes like MailManager etc..
Question is simple . Where should I put form verification process in the mvc design pattern (Zend , Symphony, Cakephp, Codeigniter) . I ask this question because i have my own framework. But i can not decide where should i handle form verification . For example , i can write if statements in controller but this makes controller "fat" , or i can add verification statements in model function ( in User::register( , , ) ) . Of course this is not very complex thing ,but my aim is to understand how do they do in enterprise level applications .
If you consider the Models in MVC as what we in the .NET world call ViewModels (and I believe are called Presentation Models elsewhere) instead of Domain Models, the Model would be an excellent place to add validation/verification.
This would allow you to reuse the verification logic anywhere you are reusing the Model, and it makes sense since the Model would be encapsulating the verification logic together with the data. That sounds like high cohesion to me.
As a sanity check, the ASP.NET MVC framework seems to be heading in that direction as well. Since the question is tagged 'php' I'm not sure this last piece of information strengthens or weakens the argument.
Validation is Control of input. MVC stands for Model View Controller, so validation should be in a controller.
General validations like isInt(), isStr(), isEmailAddress, isFloat() etc etc could/should be placed in a base controller. Then you can have subcontrollers for specified Models (mapping to your database). Those subcontrollers then extend from the base controller.
There are multiple places where validation can happen.
First, client-side versus server-side: it's frequently a good practice to do pre-validation on the client side (ex. "only numbers allowed!") before sending the bits up the wire. Server side validation is always mandatory as a security / data integrity requirement.
Front end versus model requirements: a particular form might not know of model's requirement for related data objects (for example, if there's a business logic rule that value of 3 in a particular field should not be present if the number of related records is less than 5) - the only place that would know that is the model.