I have 3 tables that contain user information, one for students, one for teachers and one for administrators.
They are not related in any way. I wan't to create a dashboard for the Administrators, where a list of students and teachers shows up.
The only way I found to achieve this was using the $uses variable in the Administrators controller. However, I have read in many places that this is bad practice.
Any solutions?
Another, perhaps better practice is the use of ClassRegistry::init('MyModel')->myMethod() (more reading # Cake API)
This only loads the object when it's used, as opposed to loadModel or uses, with ClassRegistry the models are treated as singletons.
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that you are doing something wrong: you need access to a model that has nothing to do with your current controller.
There are plenty of conditions where you would need to access all of your models data, from one controller, but never a definitive answer on how to do it without breaking convention!
You can always use another Model which is not related by using
$this->loadModel('NewModelName');
Then you can access new loaded model by:
$this->NewModelName->add(); // whatever method model has defined
Why prefer loadModel() over uses?
To gain performance. How? uses calls the loadModel function itself to load all the models you specify in uses array. But the problem is if only one of your action needs a particular model, whats the good thing to include it in every action. e.g. only add() action requires an unrelated model, but if you have specified it in uses array, no matter what action gets called a completely unrelated model is going to load. To put simply it will be inefficient. Its like you have declared variables in a C programme but never used them. In case of C compiler will warn you that you are not using your variables, but unfortunately cake couldn't tell you.
Its alright to use uses if all your actions needs to load that model, use loadModel() otherwise.
You probably didn't read my answer in your other question :))
I have 3 tables that contain user information, one for students, one for teachers and one for administrators. They are not related in any way. I wan't to create a dashboard for the Administrators, where a list of students and teachers shows up.
The problem is you are separating similar data into 3 different tables, in this case, user information. So when you try to manage this data, you hit a brick wall: because you leave out the relationships when you separate them in 3 tables.
The only way I found to achieve this was using the $uses variable in the Administrators controller.
You got the wrong idea about the controller. Each controller manage the data flow of a particular model (and related models). It doesn't mean that you have to stay in Admin controller to do administrative things. What model you want to manipulate decides what controller you need to be in.
However, I have read in many places that this is bad practice.
Now for the main question: using $uses is a red flag that you are doing something wrong: you need access to a model that has nothing to do with your current controller. Now, there're always exceptions in programming, sometimes we need to have access to that model. That's where loadModel comes in. Because it should be rare. If you need the model a lot, then you'll need to call loadModel a lot, which is cumbersome, which is what $uses is for, but then that means something's wrong with your app design :))
So, you can say using $uses is a sign of bad decision (in DB design or application structure); and so is using loadModel a lot.
Edit: Any solutions?
I gave one solution in your other question. But if you want to have them all in one place, you can have 1 users table with user information. Each User can hasOne Student, Teacher, Administrator and a 'group' field to decide what group the User is. The third solution is using $uses. Its performance impact won't be a problem really. But it will be pretty convoluted when you develop your app further. That's what you need to worry about. For example, I can say that, if you use Auth, you'll need to tweak it a fair bit to get it working with 3 models. If you use the users table, it will be a lot easier.
Related
I know this is a duplicate question but i think it will help others because there are a lot of similar apps that have these kind of table relationships:
So the question is what would be the optimal solution for all relationships in this schema using the Eloquent?
How many Models and Controllers to make?
First of all, you need to understand that not all tables in a database represent an entity.
For example, tables like users, posts, comments are entities. Whereas posts_users, comments_posts are not: they are here for technical reason, to materialize the relation between 2 entities.
Only entities need a model: it makes no sense to have a model for a relation table.
Even if a table holds information like date_created, it does not make it an entity. This is just a data related to the relation. For example, the table users_roles may have a column named date_assigned, to know when a given user was assigned a given role. It's not entitity for all that.
Second, you need to understand what a controller is for. The role of a controller is to handle a request and provide a result. Result can be a view, an error (HTTP 404), or just the fact that an action has been successfully done.
You must also make the difference between the class called Controller (or any child that extends this base class) and an actual controller. The actual controller is the code that will handle the request. A Controller class can have more than one method to handle requests.
It's all a question of organization: generally, Controller classes are used to group methods within the same scope: user login, logout, subscription, password reminder are all the same scope. All these controllers could be in different classes or functions. It does not matter. Each method is a controller. They are grouped in the same class because they have the same needs (check user is logged in, to know if login is required, if subscription page can be displayed, etc.) and they are in the same scope, which just make sense when you think of it. That's just logical: you know where to search when you need to change something about user identification (even if you are new on the project).
So you need a model for these entities:
User
Offer
Invoice
Category
The controllers you'll need depends on what you want/need to do with this data. There's no ready-to-use answer to this part of your question.
Use a Controller class for:
user authentication (if you need some)
user management (backoffice)
invoice management (edit, mark paid, list of late payments, etc.)
categories management (create, edit, delete)
offers management
But depending on your application, you may need more. Only you can really say. There's no bad answer to this question: if you think some controllers should be separated for better organization, do it. If you think you should group 2 or more, do it. There's no rule. You have to keep your code clear and well organized. It must suit your needs. That's all.
I often get confused as to which model to create functions. Let me try to explain my current situation with a simple made up example:
I have a Log model that contains all activities on our app. I want to get the activity for a specific user. Should I create a getActivity($userId) function in the User model or the Log model?
Why not both?
Of course, the main thing is to avoid code duplication as this would be difficult to maintain - and an ugly solution.
The Log Model could contain a method called getActivity() which fetches all activity (or based on any arguments needed for pagination and/or log levels). Additionally, for self-documenting purposes, create a method called getUserActivity($userId) - a method that hopefully looks selfexplainatory.
The User Model could now contain a method called getActivity() (again, with any arguments needed for pagination and/or log levels) which in turn calls the getUserActivity() method in your Log model.
Is this the smartest choice?
Well, there is never a single solution for any problem - but what I like about this solution is that you now have the possibilty to seperate the logic for each of the models, but still have a visible and functional link between them. Secondly, you know have the possibilty to chain User objects to log activity in an easy way.
Since the main used database in your function will be the "Log" one, you should place it in the Log Model.
Cake's documentation says "Most commonly, controllers are used to manage the logic for a single model." I'm finding this is uncommon for most of my code, and I don't want to break convention unless it is proper to do so.
For example, my application sends a user to their account dashboard after they log in - this uses data from probably half a dozen tables, not all of which are even related. Do I create a "dashboard" controller for this (even though there is no dashboard model or table)? Or do I create a dashboard method in an existing controller?
Thanks, Brian
I have a similar situation and how I handle it is keeping the actions that connect a lot of models in the controller that is the most centric. For instance, my user can create voicenotes, comments, has settings, has twitter and facebook information. All this information I can get from my user model $this->User->Voicenotes->find('all'), for example.
I believe creating additional controllers might just confuse you, use what cake gives you, you can specify that models are to be used in a controller either by setting the $uses variable or using loadModel in the controller action, if you have your relations set up you can just do it the way i described before, no need to create additional controllers.
I guess it depends on how you want your own app to work and what comes easier in your situation.
When building applications, whats the best way to decide what goes where. How do you know what functions to put in what controllers and models. For example, I'm building an application that is based highly on location. Users can post different things, that will in turn be shown to other users within a certain distance. Also, each user will have their own profile page that will show everything posted by that user regardless of location.
So I have models like this
class UserModel extends BaseM{
get_user($uid);
get_all_users();
edit_user($new_data);
delete_user($uid);
add_user($new_user);
get_user_articles($uid);
get_user_reviews($uid);
get_user_foo($uid);
}
class ArticleModel extends BaseM{
get_article($aid);
get_all_articles();
add_article($new_article);
delete_article($aid);
}// similar to ReviewModel, and other models
class LocalModel extends BaseM{
get_local_articles($zip_code, $range);
get_local_reviews($zip_code, $range);
get_local_foo($zip_code, $range);
}// holds all location related functions
As you can see, I lumped everything dealing with a user (needs a userID) in the userModel, everything dealing with location (needs a zip-code) in the localModel, and then everything else has its own model.
I was wondering whats the best way to figure out what goes where, is there like a rule of thumb for this kind of stuff?
Well you're 80% there already. You've got your models broken out and that is a big battle. Next design the app that you want. If you end up with a lots of repetitive "elements" on multiple pages, then each element should be a view. Otherwise each page should be a view. Or some combination of the two.
Once you have you pages defined and you know the data flow of the app, all that remains is the controller.
It may be practical in a small app to have a single controller. Or for really complex apps, you may have multiple controllers - no more than one per "page" though.
Just keep in mind - the Model should be view agnostic (you can retool the UI without impacting the model). The views should be blind to where the data comes from or where it's going - everything gets filtered through the controller.
See my previous answer to a similar question here:
I normally use this approach: try to put it somewhere. if after a while you use it, it feels awkward, then it's not in the right place.
In general every model class should have methods that make sense for itself, and eventually return other models. Refrain from putting too much computational intelligence in your models. If there's something that feels strange in either classes, there's probably a third class in between to be discovered.
A lot of frameworks use URL conventions like /controller/action/{id} which is great, but if you need any configuration beyond that, it's up to you to write your own routes.
How would you handle URLs like /users/{id}/friends on the backend? (to list all of a user's friends)
I'm thinking that in the controller, something like this would be appropriate:
class User {
function index() {
echo 'user index';
}
}
class Friend extends User {
function index($user_id) {
echo 'friend index';
}
}
Then you would have the following map:
/users -> User::index()
/users/{id} -> User::view($id)
/users/{id}/friends -> Friend::index($user_id)
I wanted to put the Friend class inside the User class but apparently you can't do that in PHP so this is the best I could come up with. Thoughts?
What URL would use for editing your list of friends? /users/{id}/friends/edit could work, but it doesn't seem appropriate, since you should never be editing someone else's friend list. Would /account/friends/edit be a better choice? Where would you put the corresponding code for that? In a friend controller, or a user controller, or a specialized account controller?
Bonus question: which do you prefer? /photos/delete/{id} or /photos/{id}/delete
The answers:
So, what I've gathered from the answers is that if the "thing" is complicated (like "friends") but doesn't have its own controller, you can give it one without a model, or if it's not, you should stuff it in with whatever it's most closely related to. Your URLs should not influence where you put your code. Most people seem to think you should stick to /controller/action/{id} whever possible, because it's what people are familiar with.
No one really commented on the extended class aside from saying it's "awkward". Perhaps FriendList would have been a more appropriate class in that case if I really wanted to separate it out.
Thanks for all the answers :)
The routes you're talking about, and the way you're using subclasses to achieve this structure, seems a bit awkward to me. The standard convention of /controller/action/{id} works great for simple actions, but if you're creating a complex application you will always need to create custom routes. There are probably some good guidelines to use when creating these routes, but it really boils down to staying consistent across your application and keeping things as simple as possible.
I don't see any good reason to have /user/{id}/friends mapping to a "Friend" controller. Why not just have "friends" be an action on the User controller? Once you actually drill down to view a specific friend's page, you could use a Friend controller (/friends/view/123) or you could repurpose your User controller so that it works for a friend or the currently logged in user (/user/view/123).
Re: the bonus question, I'd stick with /photos/delete/{id} (/controller/action/{id}) as that's the most widely accepted mechanism.
I would prefer /photos/{id}/delete. My reasoning is that if you take one component off the end of an URL, it should still make sense.
It's pretty easy to assume what /photos/{id} should do: view the set of photos for that {id}.
But what should /photos/delete do? That's really unclear.
I know that there's kind of a default convention of /controller/action/id, but that organization is for the sake of mapping to the class/method architecture of controllers. I don't think it's a good idea to organize the UI to accommodate the code (the URL is in a way part of the UI).
Re comments: Yes, /photos/{id} maybe makes more sense to view a given photo by its id. /users/{id}/photos perhaps to view a collection. It's up to you.
The point is that you should think of the UI in terms of users, not in terms of code organization.
You can do either or. The problem is when you mix the two. /users/{id}/friends and /users/friends/{id} When someone has the id of "friends" this will fail. This may seem like a trivial case but it's very popular to use usernames for ids. You will have to limit user names for every action.
Sometimes you can't do /{controller}/{action}/{id}
I did a indie music site a while back and we did
/artist/{username}
/artist/{username}/albums
/artist/{username}/albums/{album}
We didn't want to test for conditionals so we didn't do
/artist/{username}/{album}
Since we didn't want to check for anyone with an album named "albums"
We could have done it
/artist/{username}
/artist/{username}/albums
/albums/{album}
but then we would lose the SEO advantage of having both the artist name and the album name in the URL. Also in this case we would be forcing album names to be unique which would be bad since it's common for artist to have album names the same as other artist.
You could do pure /{controller}/{action}/{id} but then you would lose some SEO and you can't do URL shortening.
/artist/view/{username}
/artist/albums/{username}
/album/view/{album}
Getting back to your example.
/users/{id}/friends/edit could work,
but it doesn't seem appropriate, since
you should never be editing someone
else's friend list.
In this case it should be /friends/edit since your user id is duplicate information assuming your in a session somehow. In general you want to support URL shortening not URL expansion.
(Bonus question)
Neither, i'd use REST. DELETE /photo?id={id}
It also depends on how you are storing your data. I could imagine in some cases you need a 'friend-list' to be a entity in your model. A logical approach would then be to specify a unique identifier for each friend-list, a primary key.
This would logically result in the following route, as you only need a primary key of the friend-list to edit or delete it...
/friends/edit/{friendListId}
It's up to you to decide. As pix0r stated: convention for small applications is /{controller}/{action}/{id} where {id} should be optional to match with most of your websites actions. In some cases applications get big and you want to define specific routes with more than 3 elements. In some cases certain entities just get a bigger meaning (above example) and you could decide to define a custom controller for it (which makes the default route perfect again...).
I'd stick with the default route /controller/action/id but just don't start making controllers for everything (like friends) in the beginning. The Model-View-Controller pattern makes it very easy for you to change routes later on, as long as all your route-links and actions (forms etc.) are generated based on routes and actions. So you don't really have to bother that much :)
The URLs themselves don't really matter too much. What is more important is what goes in each of your controllers. In your example you had your friend list extend the User class. If your list of friends is really just a list of users, maybe it should extend the Users controller so that you deal with lists of users in one place.
class Users {
public function index() {
$users = $this->findUsers();
}
protected function findUsers($userId=null) { ... }
}
class Friends extends Users {
public function index($userId) {
$users = $this->findUsers($userId);
}
}
If you have a hard time figuring out which class to extend write out what you need from each of the classes and pick the one with the longest list.