Laravel 5.2: ModelNotFoundException for specific models - php

I'm fairly new to coding in Laravel, and I've been following the Laravel Basics videos by Jeffery Way. Right now I'm working on building my own site that will allow users to register, send and receive messages, and post to a forum.
I'm setting up sending/receiving messages and have it working well enough, but what I want to do is safe-guard against a user trying to send a message to an invalid username.
The form is very basic for now: 'send_to' takes a username, 'title', and 'body'.
My Message model has a mutator that queries the database for that username and sets the 'send_to' field to that user's id.
public function setSendToAttribute($value)
{
$user = User::where('name', $value)->firstOrFail();
$this->attributes['send_to'] = $user->id;
}
What I'd like to do is catch an exception if the username is invalid. I've done that with the Handler.php file as below:
public function render($request, Exception $e)
{
if($e instanceof ModelNotFoundException)
return $e->getmessage();
return parent::render($request, $e);
}
So this works great and will will return the message "No query results for model [App\User]. What I'd prefer to do though is set it so it returns to the form again with the title and body filled out, and an error message saying that the username is not registered.
One other part to this, can this be done separately from all ModelNotFoundExceptions so if I'm trying to look up a specific message it won't return that a User was not found?

Instead of hiding the logic inside a mutator, you can create a FormRequest or validate the user in your controller.
Using validation rules, you can check the input for user existence, and redirect back on failure, or return a 422 error in case that you're using an ajax request (with the header Accept: application/json)
I'd highly recommend you to read about validation and check this specific rule I link below:
https://laravel.com/docs/5.2/validation#rule-exists
Then, once you're sure that the user exists in the database (remember to validate that the user is unique when you create it), you can write some logic to insert the user id instead of the username, if you want of course.

Related

PHP MVC: Best Practice and Right way for print data validation error

I have Php Login system using MVC structure. For database data validation I create LoginModel. I need to print failure error to view like: User Not Exist Now Which way is right and better:
1- Add error data validation in Login Model and get in Controller and Print to View Like This:
class LoginModel extends \App\Core\Model
{
public function login($user_name, $user_password, $set_remember_me_cookie = null)
{
$returnError = array();
// checks if user exists, if login is not blocked (due to failed logins) and if password fits the hash
$result = $this->validateAndGetUser($user_name, $user_password);
// check if that user exists.
if (!$result) {
$returnError['isMessage'] = false;
$returnError['name'] = "User Not Found";
}
return $returnError;
}
private function validateAndGetUser($user_name, $user_password){
//Check User Data Validation
}
}
2- Add Only True Or False in LoginModel and Get in Controller And Set Error Name and Print to View Like This:
class LoginModel extends \App\Core\Model
{
public function login($user_name, $user_password, $set_remember_me_cookie = null)
{
// checks if user exists, if login is not blocked (due to failed logins) and if password fits the hash
$result = $this->validateAndGetUser($user_name, $user_password);
// check if that user exists.
if (!$result) {
return false;
}
return true;
}
private function validateAndGetUser($user_name, $user_password){
//Check User Data Validation
}
}
In action my really question is: Can I add error message in Model and Get in Controller?! Which way is right and true?
There are many ways to do this.
For me the best way is the first way you have suggested, but better declare bug reports in a single file eg errors.php and make the model return you array with 2 keys, the first key is always TRUE or FALSE and then if your model returns the first key FALSE reads the error number from the second key.
Then, in the controller you can replace the error number with the corresponding key in the array you declared in errors.php
If the first key is TRUE, then the second key will be your user information.
Suggestion:
Split the login functionality into two (main) steps:
Check if the posted user already exists. If not, throw an exception.
Match the posted password against the stored one. If they don't match, throw an exception. I suggest the use of password_hash for storing passwords, and of password_verify for matching a password with the stored one.
Then - based on your current architecture, in your controller, use a try-catch block to catch the exception thrown by the login steps and proceed as you wish to display the exception message to the user.
Just as a note: In case of an ajax request, you would send a specific response header (with status code 500, for example) or a custom response header (with status code 420, for example) back to the client, e.g. browser, in order to activate the error function of the ajax request.
Notes:
The domain model is a layer. And it must have no knowledge about the outside world.
A controller should only (!) update the domain model (through services).
A view should be a class - not a template file - responsible with fetching data from the model layer (through services), preparing/formatting it for presentation, and passing it to a response object, in order for this to be returned and printed.
The controller and the view (mostly 1:1 relation) should be created separately. The controller should not have any knowledge about the view. This creation step would take place in the front-controller class or file.
As for error reporting, I would recommend to read this.

Laravel 4 custom validation rule

I am little confused as to whether a custom validation rules needs to return true or false to fire.
I am validating an email address to make that it does already belong to another model via a relationship.
Validator::extend('email_exists', function($attribute, $value, $parameter){
$user = User::where('email', '=', $value)->with('clients')->first();
//Does the user exits, and are they already a member of this client?
//We know this by looking at the client id, and comparing them the current ID.
if($user != NULL) {
if(in_array(Input::get('client_id'), $user->clients->lists('id'))) {
return false;
} else {
return true;
}
} else {
return true;
}
});
What I am trying to above is, find if a user exists with the entered email, if it does exist, then check if the email is related to any clients, and if any of those clients id match the client id in the POST, if the email exists and is related to client id in the POST I want to return an error, other wise I happy for the POST to processed.
At the moment, I think I am allowing anything through. Am I using the custom rule correctly, and what should return if I want to throw an error?
I think you're approaching this the wrong way. Instead of the stress of extending the Validator class for a singular use case, you should consider simply adding a message to the message bag with your input element as the key. e.g.
$validator->messages()->add('client_id', 'This email is already associated with a client');
Tip: I usually add a rules array to my models and inject a Validator class so I can easily validate the model without having to create an instance of the Validator or writing a rules array all the time.

Model now doing data/form validation. How to return user friendly error messages to the view?

Since today I have started validating form data in my Model layer instead of in my Controllers. I am going to shorten the code snippets as much as possible.
This is a method from my User domain object (setLastName() method is basically the same)
public function setFirstName($firstName) {
if(!$firstName) throw new \InvalidArgumentException('Some message');
if( strlen($firstName) < 2 || strlen($firstName) > 20 ) throw new \LengthException('Some message');
if(preg_match('/[^a-zA-Z\'.-\s]/', $firstName)) throw new FormatException('Some message');
$this->firstName = $firstName;
}
In my Controller I have something like this
$userService = $this->serviceFactory->build('User');
try {
$userService->register('John', 'M');
}
catch(\InvalidArgumentException $ex) {
}
catch(\LengthException $ex) {
}
catch(etc etc)
In my UserService method register() I have something like
$user->setFirstName($firstName);
$user->setLastName($lastName);
When running the setFirstName() method it will successfully set the supplied first name. The setLastName() method will throw a LengthException as it is too short.
That is what I want but when that comes back to the service layer and then to the controller and I catch it I know that a LengthException was thrown but I can't give the user a proper message like "The supplied last name was too short" because I do not know for which field the exception was thrown, just the type of exception.
How do I get around this? Thanks.
View instances should be requesting information from the model layer. Controllers is not responsible for passing the information.
This would also mean that you obsessive-compulsive use of exceptions, that cause your abstraction layers to leak, would be completely pointless. "Error" is just a state of model layer. It is an expected situation, not an exception.
Controllers in MVC are responsible for changing the state of model layer and (quite rarely) the state of current view instance. They should not be receiving any feedback from services.
Instead of returning some message, why not return a useful error message such as "supplied First name is too short". This can then be returned to the user.
Alternatively you can see that when extending exceptions you can specify additional information such as numeric codes - you could of course use this.
Or of course you can create a subclass of Exception for difference circumstances, but you could end up with hundreds of Exception subclasses which would of course be messy.
I have the same question. I think that most of the people who say that all the validation should be done in the model never developed a full PHP MVC application themselves and only know books and theory. Never a piece of code is seen about that topic.
Anyway I have thought of a possible solution. What do you think about the code below:
// Controller
$user = User::make(
$_POST['lastname'], $_POST['firstname'],
$_POST['gender'], [...]
);
if(is_array($user)) {
// store the errors in a view variable and forward, or store in session and redirect
$_SESSION['errors'] = $user;
$this->_redirect('add');
exit;
}
// Model
public static make($lastname, $firstname, $gender, [...]) {
$errors = array();
if(/* test firstname */) $errors[] = 'model_error_firstname';
if(/* test lastname */) $errors[] = 'model_error_lastname';
if(!empty($errors)) return $errors;
return new User($lastname, $firstname, $gender, [...]);
}
The model would have a static function that will return either an array with errors in case something went wrong, or a new model object if validation was ok.
In your controller you test whether an array was returned or not.
Maybe I would put the constructor of the User as private, because if you build a user with the constructor directly, you would skip all the validations. But this does not mean that it becomes a Singleton.
Maybe I would also sanitize the form fields and make them safe before passing them to the model.
The keys like model_error_xyz would be found in a translation file with the appropriate text.
Update:
Actually I think that you could just throw a custom exception from the constructor and that contains an array of messages. But the reason that I didn't propose that, is that it leads to half-constructed objects, at least in Java for example, but hey, PHP is not Java...
You would also have to validate each setter function :( it seems tedious to do validation in the model instance.
Any thoughts are welcome.

How flexible do some simple things on form validation success in Symfony2?

I have a form that contains two fields to upload files. I need to execute the following points:
validate the form;
move files to another directory;
handle the moved files;
return the result of handling.
Also I must return error messages if one of above points was failed. I am confused how to do that more flexible. I don't want to do all in controller.
I created form handler, form model, form type as in FOSUserBundle and added validation rules to form model in validation.yml. Form validation works fine.
I have an idea to use event dispatcher for this issue. After form validation I can notify event listeners.
What do you think?
It depends.
If you need to subscribe to the event because you need to perfom different actions (e.g. email the support, clean up trash, write down a failure log in the database), use event dispatcher. But if it's a simple thing like just display an error, it makes sense to use exceptions instead:
if ($form->isValid()) {
try {
$entity->handle();
} catch (FileHandleException $e) {
...
} catch (RuntimeException $e) {
...
}
}
Another option depends on what 'handle the moved files' is. If it's a part of validation (handle them to find that they are valid ssh keys, for example) and not business logic, then you can create a new validator and it'll become a part of form validation.

PHP advice please. (Kohana experience a plus)

I've been working with PHP for about a year, but I do it as a hobby. I dont have anybody I can go to as a teacher or a mentor to give me advice on what I may be doing completely wrong, or what I could do better. I've done quite a few different things within that year, so I wouldnt consider myself a complete noob.
Anyways, I have just started using a framework (Kohana), and there really arent that many tutorials out there, so I'm not entirely sure if I'm doing things in a good way.
I have a few code snippets that I would like to post to get some feedback pertaining to what I just said.
For Starters
User Controller
class User_Controller extends Template_Controller{
public function register()
{
// logged in users cant register
if($this->logged_in)
{
url::redirect('user/profile');
}
// initially show an empty form
$form = $errors = array
(
'username' => '',
'email' => '',
'password' => '',
'gender' => '',
'dob_month' => '',
'dob_day' => '',
'dob_year' => '',
'date_of_birth' => '',
'captcha' => '',
'registration' => ''
);
// check for a form submission
if($this->input->post('register'))
{
// get the form
$post = $this->input->post();
// prepare the data for validation
$post['date_of_birth'] = "{$post['dob_year']}-{$post['dob_month']}-{$post['dob_day']}";
// create a new user
$user = ORM::factory('user');
// validate and register the user.
if($user->register($post, TRUE))
{
// SEND EMAIL
// login using the collected data
if(Auth::instance()->login($post->username, $post->password, TRUE))
{
// redirect the user to the profile page
//url::redirect("user/profile/{$user->id}");
}
}
// get validation errors and repopulate the form
$form = arr::overwrite($form, $post->as_array());
$errors = arr::overwrite($errors, $post->errors('registration_errors'));
}
// template variables
$this->template->title = 'Sign Up';
$this->template->body = new View('layout_1');
// layout variables
$this->template->body->left = new View('user/registration_form');
$this->template->body->right = 'Right Side Content';
// registration form variables
$this->template->body->left->form = $form;
$this->template->body->left->errors = $errors;
$this->template->body->left->captcha = new Captcha('register');
}
}
Register Function within User_Model
class User_Model extends ORM{
public function register(array& $user, $save = FALSE)
{
$user = new Validation($user);
// logged in users cant register
if(Auth::instance()->logged_in())
{
$user->add_error('registration', 'logged_in');
return FALSE;
}
// trim everything
$user->pre_filter('trim')
// everything is required
->add_rules('*', 'required')
// username must be 5 - 30 alphanumeric characters and available
->add_rules('username', 'length[5,30]', 'valid::alpha_numeric', array($this, 'username_available'))
// email must be valid format and available
->add_rules('email', 'valid::email', array($this, 'email_available'))
// password must be 5 - 15 characters and alpha dash
->add_rules('password', 'length[5,15]', 'valid::alpha_dash')
// gender must be either male or female. capitalize first letter
->add_rules('gender', array($this, 'valid_gender'))
->post_filter('ucfirst', 'gender')
// dob must be a valid date, and user must be old enough.
->add_callbacks('date_of_birth', array($this, 'check_dob'))
// captcha must be entered correctly.
->add_rules('captcha', 'Captcha::valid');
// add the registration date
$this->registration_date = date::unix2mysql(); // helper function transforms the current unix to mysql datetime format
// validate the information. an ORM function.
$result = parent::validate($user, $save);
// was the user info valid?
if($result === TRUE)
{
// was the user saved?
if($save === TRUE)
{
// add a login role
$this->add(ORM::factory('role', 'login'));
$this->save();
}
}
else
{
$user->add_error('registration', 'failed');
}
return $result;
}
}
Mostly all my models follow the same format when validating info.
I have some other things I would appreciate feedback on as well, but I dont want to overwhelm anybody.
Thanks a lot for your time
EDIT: I'm sorry, I should've posted both the user controller and model. I've been reading alot about how models should be fat, and controllers should be skinny. Thats why I created a register function in the model to validate the info instead of doing so within the controller. The register function takes an array, but turns that array into a validation object so that I can retrieve the user input, and the errors. I've seen a few tutorials on Kohana where it was done this way.
First, I would not put the register() method into the User model. A model should be a representation of the object in the database and generally only contains your "CRUD" methods (create, retrieve, update, delete), getter and setter methods, and maybe some static helper methods related to the model. By putting your register() method into the model, you're making the model do presentation logic that should really be done by a User controller, since this is a response to a user action. A controller handles user actions, validates those user actions, then updates the model if the validation is successful.
In your example, the user is attempting to create a new account. He fills out a form and clicks submit. The form's POST action should point to a controller's method, like /user/register, and that method will use the Validation library to validate the form data sent by the user. Only if that data validates successfully should you create a User model instance, set the properties of that model to what the user input, and then use the model's save() method to save to the database. If the validation fails, you report the error to the user and you don't create a User model at all since you don't have a valid data set to create a model with yet.
Next, you are checking to see if the user is logged in. Again, this should be in the controller, not the model. Besides that, the user should not be able to get to this register process in the first place if he is already logged in. The controller method that creates the user registration form view should check to see if the user's logged in, and if he is, then he should be redirected to another page. Even if the user is playing tricks and manages to submit the form (maybe he logged in via another window while having the form open in an old window), your register method should check for that first and not create a $user Validation object yet.
I can see in your code that there are some confusing items based on your model set up. For example, you're passing the $user array into the method, which I presume is the form data. But you're using the "pass by reference" operator (&) which is unnecessary in PHP5 since all objects are now passed by reference. But after that you're recasting $user as a Validation object. Are you using the $user Validation object elsewhere and require it to be passed by reference? If so, that's another flaw in the logic as all of this processing needs to be in the controller and the $_POST values can be used directly in the controller instead of having to pass around a Validation object.
Later on, you're validating the user information with parent::validate($user, $save). Why is the validate() method being called on parent as a static method? If this is a model, it should be extending Kohana's core Model class, and "parent" references the Model class. Is your model extending the Validation class? Also, why are you passing in the $user Validation object to the validation() method? Doing that is required if you need to do recursion (to validate elements again after making changes from previous filters), but it looks like you're not doing anything to require recursion. You should be calling validate() on the $user Validation object:
$user->validate();
without any arguments. The validation errors will become part of the $user object, so you can check for errors using
$user->errors();
Finally, while Kohana allows you to use method chaining, I would not use one long chain to set up the rules and other items for the validation. It's confusing and may cause debugging to be difficult. Put each of those on its own line and perform each directly on the $user object.
I dont know Kohanna so im not sure what the lay of the land is on their MVC separation but typically i would make register an action on a controller. The main thing i disagee with in your code is that the Model is coupled to the Authentication system internally. The authentication check should be made outside the class and the control flow decision should be made outside as well, OR the result of the authentication check should be passed in to the Model for use in its internal operation.
Typically i might do something like the following pseudo code:
// in my controller class for User or whatever
public function registerAction()
{
// get the form data from the request if its POST, ortherwise a blank array
$userData = $this->getRequest('user', array(), 'POST');
// create a user
$user = new User($userData);
if(Auth::instance()->logged_in())
{
// we are logged in add an error to the user object for use by the view
$user->getValidator()->add_error('registration', 'logged_in');
}
elseif($user->is_valid())
{
// user data is valid, set the view with the success message
$user->save();
$this->setView('register_success');
}
/**
* render the designated view, by default this would be the one containing the
* registration form which displays errors if they exist - however if we success-
* fully registered then the view with the success message we set above will be
* displayed.
*/
$this->render();
}

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