I am so confused about how to implement and how to follow SRP (single responsibility principle ) in a Laravel controller.
Suppose we have a controller which we have to do these things:
e.g
public function StorePost() {
// check user login()
//check number of current user Post count =>which must be less than 10
//store post
//send an email to user which your post has saved
//return =>api:json /web : redirect
}
I know that I can implement some DB queries in the repository but I don't know how to implement others of my logic code to achieve SRP
Also, I know there is a Heyman package to achieve these but I want to implement it by myself.
SRP in this context basically means each class and method should only be responsible for a single behaviour/feature. A rule of thumb is a class or method should change for one reason only, if it changes for multiple reasons, it needs to be broken down into smaller parts.
Your storePost method should not bother with checking the user login, that should be handled elsewhere before invoking storePost. storePost shouldnt change if the auth mechanism changes like switching from api token to json web token or something else. Laravel does this in the middleware level with the auth middleware.
Checking the users post count, this can be checked in the validation stage. storePost shouldn't change if we add more validation logic. In Laravel you can use FormValidation for this
For storing the post, the controller doesn't need to know how to call the DB, you can use the active record style using the model class or maybe create a service or repository class if your use case requires that. storePost shouldn't change if we decide to change DB vendor like going NoSQL.
For sending email, again the controller doesnt need to know how to send the email like what the subject/body recipients are. storePost shouldnt change if we need to change the email layout. Laravel has Notification for that
For serialising the response to json, the controller doesnt need to know how to format the response. if we decide to update how our json looks, storePost shouldnt change. Laravel has API Resources for that
So, ultimately in this example, the responsibility of the controller method is basically to glue all these together. It basically does what you wrote down, it only responsible for maintaining the step by step behavior, everything else is delegated to someone else. if the behavior change, like adding new behavior e.g notify all follower, storePost will change.
Related
I need to use use response caching for certain controller actions based on the country the request is coming from.
I have figured out how to get the country code from the request (it involves reading from a database, expensive, so I want to do this just for the actions that require a country), but I am not sure how to do the caching part.
I am thinking of writing a middleware (e.g., named CountryResolver)that will run before the response caching middleware and set the country SOMEHOW in the request and have the Response Cache middleware vary by country.
app.UseCountryResolver();
app.UseResponseCaching();
There are two main problems I am facing:
Problem 1-
I need that middleware not to run for every request, but only for some requests that are routed to country-specific actions. I am thinking of annotating such country-specific actions via a custom attribute (e.g., [CountryRequired]).
[CountryRequired]
[ResponseCache(VaryByQueryKeys = new string[] { "country"}]
public IActionResult MyAction()
{
However I don't know how the middleware can pickup the actions that have such annotation so it can decide whether to lookup the country or not.
Problem 2- "...set the country SOMEHOW in the request"
I was thinking of using VaryByQueryKeys and have the middleware set the country to a query string key named "country" BUT HttpContext.Request.Query collection is readonly. So I am not sure what other mechanism can I use for this.
Any help is very appreciated.
I would like to know the usage scenario of POST vs PUT in a WebAPI . I know the basic concepts that POST is for creating resource and PUT is for updating resource but not able to fully understand why we need a PUT over a POST.
I have 2 WebAPI methods which creates/updates data to my SQL store
1. CreateUser(UserDto)
2. UpdateUser(UserDto)
UserDto contains userId, username and email.
I can use POST for both CreateUser and UpdateUser methods which creates and updates user to my store.
Then what is the real advantage of using POST for CreateUser and PUT for updateuser? Is it just a standard/convention?
Thank you
POST always creates something new. PUT updates a existing thing. It is a convention.
You should have:
POST /users : to create a new user. The payload should not include the ID
PUT /user/(id) : to replace a user DTO with the data in the payload. Again, the payload should not contain an user id
PATCH /user/(id): to update specific members of the user, but the id.
It is a design convention, like software design patterns, to make it easy to communicate and understand by whoever has to consume the API.
POST is usually used to add a new resource into collection of resources.
Like this: POST /users.
This operation is NOT idempotent and it will have a side effect at each call.
While PUT is usually used with a replace semantic and you know the exact resource which you want to replace.
Like this: PUT /users/1.
This operation is idempotent and it will not have any side effects on subsequent calls.
When a user Register, I want to add location data for the user.
I get those with GeoIP.
So, each time a user is created, I would like somewhere to add Country, City, etc.
I was thinking about setting Hidden fields in view, but I think it a hugly way to do it, and I'm sure there is a better way to do...
Any Idea???
Any time I create a record that needs extra data, involves inserting additional records into additional tables, etc, I create a service class. Something like "UserCreator" then I pass it the input, do any additional operations, wrap multiple database calls in a transaction and so on.
That said there are so many ways to do what you want. You could Input::merge(...) then save, you could separate the process of creating a user from your controller / route function, etc.
If you are just getting started with Laravel and/or your project is rather simple, then you probably want to look at Input::merge
I solved it using Request Contructor as said here in laracast
In the Form Request's constructor I inject \Illuminate\Http\Request. I can then add my value to the request instance as such:
public function __construct(\Illuminate\Http\Request $request)
{
$request->request->add(['date_of_birth' => implode('-', $request->only('year', 'month', 'day'))]);
}
I'm just getting started with Apiary and I can't tell if this is a limitation of the product or just me not understanding what to do.
I'm documenting an API which authenticates the user as part of every request. Sometimes the authentication is part of the path (a request for the user's profile would have the user id in the path), other times just as parameters (?user_id=1&auth=secret), and for POST requests, part of the incoming body as JSON.
Also, there are 3 methods of authentication in the app. You can log in with a Facebook UID, email address, or using the unique id of the device you're using. The result is something that looks like this:
##User [/user/{facebook_uid}{?access_token}, /user/{email}{?device_id}, /users/{device_auth_id}{?device_id}]
This works fine, and displays in the API as I'd expect:
But this introduces 2 issues:
1) If I wanted to add a set of parameters shared by all authentication methods, I would need to add it to all 3 like this:
## User [/user/{facebook_uid}{?access_token, extra_thing, this_too},
/user/{email}{?device_id, extra_thing, this_too},
/users/{device_auth_id}{?device_id, extra_thing, this_too}]
This seems a bit messy, it'd be much nicer to apply shared parameters at the end of the path array so they apply to all, something like this:
## User [/user/{facebook_uid}{?access_token}, /user/{email}{?device_id}, /users/{device_auth_id}{?device_id}]{&extra_thing, this_too}
But this doesn't work. Is there a way to do this? The documentation wasn't very helpful with more complicated stuff like this.
Also, would there be a way to create some kind of template which I could apply to all my methods? In the case where the authentication is part of the path its a bit unavoidable, but for other requests it would be nice to just do something like include: authentication and have it pull the unique_id/auth combo from a defined template somewhere.
Thanks!
First, there isn't really support for having a single model with multiple resource representations. It is an unusual thing to do and is actually good food for thought.
Second, using multiple URIs in [path segment] is probably going to confuse Apiary's mock server and make it unusable.
In my opinion, I'd split this into three models: Facebook User, E-mail User and Device User, with slightly different documentation (how are they created? Can you really create all of them through api? etc. etc.)
It also depends on how you want to document this. As path segments are not validated (it would be strange to have different resources based on the type of the arguments), you can just have (and I'd personally do just that)
## User [/user/{id}{?access_token, extra_thing, this_too}]
+ Parameters
+ id (required, string, `test#example.com`)...id of the user. Can be either user's e-mail, facebook id or device id from where user was created.
As for reusable parts, this is currently being implemented with authentication being part of that.
Say you have a User model. The controller is attempting to create a new User. Should the controller check that the username is valid, and the password is long enough, and the first and last name are filled out, etc? Or should you pass all that data straight to the User model via a Create method? The Create method would then return a true on success, or false on failure?
If it's the latter (and I think it is), how do the error messages get sent back to the controller (so they can be displayed in a view)? Should you pass an errors array to the Create method which the model augments? Or should the model keep an internal store of errors, with appropriate accessors? I don't like either method...is there a better way?
These errors don't seem exceptional, so I don't think exception handling is appropriate.
Edit: I'm using PHP for this project, but I use Python too.
For the first question, the model should do the verifications (and use some form of error handling to notify the controller and view that errors did or did not occur). For the second, it depends on what programming language / framework you are using... What are you using?