cakephp3 custom validation - php

I have a duration field that sometimes can be empty and sometimes can't, depending on the other data sent by the form. So I'm trying to do custom validation in CakePHP3.
In my table I did
public function validationDefault(Validator $validator)
{
$validator
->add('duration', 'durationOk', [
'rule' => 'isDurationOk',
'message' => 'duration is not OK',
'provider' => 'table'
]);
return $validator;
}
public function isDurationOk($value, $context)
{
// do some logic
return false; // Always return false, just for test
}
Now when I set the value for duration field I get an 'duration is not OK' error (as expected). But when I let the value empty I get a 'This field cannot be left empty' error.
So I added:
->allowEmpty('duration');
But in this case when duration is empty I don't get an error at all.
Am I doing something wrong or it's just me don't understanding how validation works?

Let me read the book for you:
Conditional Validation
When defining validation rules, you can use the on key to define when
a validation rule should be applied. If left undefined, the rule will
always be applied. Other valid values are create and update. Using one
of these values will make the rule apply to only create or update
operations.
Additionally, you can provide a callable function that will determine
whether or not a particular rule should be applied:
'on' => function ($context) {
// Do your "other data" checks here
return !empty($context['data']['other_data']);
}
So just define the conditions depending on your "other data" in the callback to apply the rule only when the conditons are true.
Alternatively you can manipulate the plain form data even before it gets validated in the beforeMarshal() callback of the table and change the form data as needed or load another validator or modify the validator.

Related

Laravel Validation: only allow known properties/attributes, otherwise fail validation

We are building an api endpoint where precision is required. We want to enforce strict validation on the parameters that are POST/PUT to the server.
If the api user sends a key=value pair that is not supported (eg. we allow the parameters [first_name, last_name] and the user includes an unsupported parameter [country]), we want the validation to fail.
Have tried building a custom validator called allowed_attributes (used as allowed_attributes:attr1,attr2,...), but for it to be usable in a $validationRules array, it has to be applied to the parent of a list of nested/child attributes (...because otherwise our custom validator did not have access to the attributes being validated).
Validator::extend('allowed_attributes', 'App\Validators\AllowedAttributesValidator#validate');
This created issues with other validators, where we then had to anticipate this parent/child structure and code around it, including additional post-validation clean-up of error keys and error message strings.
tl;dr: very dirty, not a clean implementation.
$validationRules = [
'parent' => 'allowed_attributes:first_name,last_name',
'parent.first_name' => 'required|string|max:40',
'parent.last_name' => 'required|string|max:40'
];
$isValid = Validator::make(['parent' => $request], $validationRules);
var_dump("Validation results: " . ($isValid ? "passed" : "failed"));
Any ideas/suggestions on how this can be accomplished more cleanly in laravel, without requiring the use of parent/child relationship to get access to the list of all $request attributes (within the custom validator)?
I preferred to post a new answer as the approach is different from the previous one and a bit more cleaner. So I would rather keep the two approaches separated and not mixed together in the same answer.
Better problem handling
After digging deeper into the Validation's namespace's source code since my last answer I figured out that the easiest way would have been to extend the Validator class to remplement the passes() function to also check what you needed.
This implementation has the benefit to also correcly handle specific error messages for single array/object fields without any effor and should be fully compatible with the usual error messages translations.
Create a custom validator class
You should first create a Validator class within your app folder (I placed it under app/Validation/Validator.php) and implement the passes method like this:
<?php
namespace App\Validation;
use Illuminate\Support\Arr;
use Illuminate\Validation\Validator as BaseValidator;
class Validator extends BaseValidator
{
/**
* Determine if the data passes the validation rules.
*
* #return bool
*/
public function passes()
{
// Perform the usual rules validation, but at this step ignore the
// return value as we still have to validate the allowance of the fields
// The error messages count will be recalculated later and returned.
parent::passes();
// Compute the difference between the request data as a dot notation
// array and the attributes which have a rule in the current validator instance
$extraAttributes = array_diff_key(
Arr::dot($this->data),
$this->rules
);
// We'll spin through each key that hasn't been stripped in the
// previous filtering. Most likely the fields will be top level
// forbidden values or array/object values, as they get mapped with
// indexes other than asterisks (the key will differ from the rule
// and won't match at earlier stage).
// We have to do a deeper check if a rule with that array/object
// structure has been specified.
foreach ($extraAttributes as $attribute => $value) {
if (empty($this->getExplicitKeys($attribute))) {
$this->addFailure($attribute, 'forbidden_attribute', ['value' => $value]);
}
}
return $this->messages->isEmpty();
}
}
This would essentially extend the default Validator class to add additional checks on the passes method. The check compute the array difference by keys between the input attributes converted to dot notation (to support array/object validation) and the attributes which have at least one rule assigned.
Replace the default Validator in the container
Then the last step you miss is to bind the new Validator class in the boot method of a service provider. To do so you can just override the resolver of the Illuminate\Validation\Factory class binded into the IoC container as 'validator':
// Do not forget the class import at the top of the file!
use App\Validation\Validator;
// ...
/**
* Bootstrap any application services.
*
* #return void
*/
public function boot()
{
$this->app->make('validator')
->resolver(function ($translator, $data, $rules, $messages, $attributes) {
return new Validator($translator, $data, $rules, $messages, $attributes);
});
}
// ...
Pratical use in a controller
You don't have to do anything specific to use this feature. Just call the validate method as usual:
$this->validate(request(), [
'first_name' => 'required|string|max:40',
'last_name' => 'required|string|max:40'
]);
Customize Error messages
To customize the error message you just have to add a translation key in your lang file with a key equal to forbidden_attribute (you can customize the error key name in the custom Validator class on the addFailure method call).
Example: resources/lang/en/validation.php
<?php
return [
// ...
'forbidden_attribute' => 'The :attribute key is not allowed in the request body.',
// ...
];
Note: this implementation has been tested in Laravel 5.3 only.
It should work for simple key/value pairs with this custom validator:
Validator::extendImplicit('allowed_attributes', function ($attribute, $value, $parameters, $validator) {
// If the attribute to validate request top level
if (strpos($attribute, '.') === false) {
return in_array($attribute, $parameters);
}
// If the attribute under validation is an array
if (is_array($value)) {
return empty(array_diff_key($value, array_flip($parameters)));
}
// If the attribute under validation is an object
foreach ($parameters as $parameter) {
if (substr_compare($attribute, $parameter, -strlen($parameter)) === 0) {
return true;
}
}
return false;
});
The validator logic is pretty simple:
If $attribute doesn't contains a ., we're dealing with a top level parameter, and we just have to check if it is present in the allowed_attributes list that we pass to the rule.
If $attribute's value is an array, we diff the input keys with the allowed_attributes list, and check if any attribute key has left. If so, our request had an extra key we didn't expect, so we return false.
Otherwise $attribute's value is an object we have to check if each parameter we're expecting (again, the allowed_attributes list) is the last segment of the current attribute (as laravel gives us the full dot notated attribute in $attribute).
The key here is to apply it to validation rules should like this (note the first validation rule):
$validationRules = [
'parent.*' => 'allowed_attributes:first_name,last_name',
'parent.first_name' => 'required|string|max:40',
'parent.last_name' => 'required|string|max:40'
];
The parent.* rule will apply the custom validator to each key of the 'parent' object.
To answer your question
Just don't wrap your request in an object, but use the same concept as above and apply the allowed_attributes rule with a *:
$validationRules = [
'*' => 'allowed_attributes:first_name,last_name',
'first_name' => 'required|string|max:40',
'last_name' => 'required|string|max:40'
];
This will apply the rule to all the present top level input request fields.
NOTE: Keep in mind that laravel validation is influenced by order of the rules as they are putted in rules array.
For example, moving the parent.* rule on bottom will trigger that rule on parent.first_name and parent.last_name; as opposed, keeping it as the first rule will not trigger the validation for the first_name and last_name.
This means that you could eventually remove the attributes that has further validation logic from the allowed_attributes rule's parameter list.
For example, if you would like to require only the first_name and last_name and prohibit any other field in the parent object, you might use these rules:
$validationRules = [
// This will be triggered for all the request fields except first_name and last_name
'parent.*' => 'allowed_attributes',
'parent.first_name' => 'required|string|max:40',
'parent.last_name' => 'required|string|max:40'
];
But, the following WON'T work as expected:
$validationRules = [
'parent.first_name' => 'required|string|max:40',
'parent.last_name' => 'required|string|max:40',
// This, instead would be triggered on all fields, also on first_name and last_name
// If you put this rule as last, you MUST specify the allowed fields.
'parent.*' => 'allowed_attributes',
];
Array Minor Issues
As far as I know, per Laravel's validation logic, if you were up to validate an array of objects, this custom validator would work, but the error message you would get would be generic on the array item, not on the key of that array item that wasn't allowed.
For example, you allow a products field in your request, each with an id:
$validationRules = [
'products.*' => 'allowed_attributes:id',
];
If you validate a request like this:
{
"products": [{
"id": 3
}, {
"id": 17,
"price": 3.49
}]
}
You will get an error on product 2, but you won't be able to tell which field is causing the problem!

CakePHP 3 custom validation: how to compare new value with old value during edit?

I have a case where I want to allow user to only increase value during edition. To do so I'd have to compare new value passed in request with old value from entity stored in DB.
Custom validation function receives two arguments: $check, which is a value to be validated and array $context which contains other values from submitted form.
What is the best way to validate edition in the manner I need in CakePHP 3? Is it even possible with validation rules?
you can use Application Rules
You have to create a new new rule in your Table object
suppose that the field that you want to check is priority
So in your rule you check the value of priority (that has just been changed) against the original value stored in $entity->getOriginal('priority')
public function buildRules(RulesChecker $rules)
{
// This rule is applied for update operations only
$rules->addUpdate(function ($entity, $options) {
if($entity->priority >= $entity->getOriginal('priority'))
return true;
else
return false;
},
'CheckPriority', // The name of the rule
[
'errorField' => 'priority', // the field you want
// to append the error message
'message' => 'You have to set a higher Priority' // the error message
]);
return $rules;
}

Conditional form validation in CakePHP 3

I want to validate some fields from validationDefault() function not all because of conditions but did not find any solution.
Example:
public function validationDefault(Validator $validator) {
$validator
->requirePresence('title', 'create')
->notEmpty('title');
$validator
->requirePresence('inquiry')
->allowEmpty('inquiry');
$validator
->requirePresence('dosage')
->allowEmpty('dosage');
$validator
->requirePresence('dosage_occurance')
->integer('dosage_occurance')
->allowEmpty('dosage_occurance');
return $validator;
}
Note: Response coming from two diffrent form first contains(title and inquiry) other contains(title, dosage and dosage_occurance).
I want to validate it from validationDefault() but it give me error
"dosage_occurance": {
"_required": "This field is required"
}
when I am not sending dosage_occurance which is correct but according to condition it is wrong.
using fieldList while creating new entity but it is not working.
Thanks
You want conditional validation.
Taken from the documentation:
When defining validation rules, you can use the on key to define when a validation rule should be applied. If left undefined, the rule will always be applied. Other valid values are create and update. Using one of these values will make the rule apply to only create or update operations.
Read the whole documentation page.
Example taken from there, pay attention to the on part.
$validator->add('picture', 'file', [
'rule' => ['mimeType', ['image/jpeg', 'image/png']],
'on' => function ($context) {
return !empty($context['data']['show_profile_picture']);
}
]);

CakePHP 3 - Cake trying to validate notEmpty for some reason

My table is throwing a default "notEmpty" validation error, even though I have not written any validation of the sort.
Basic validation in my Table class:
public function validationDefault(Validator $validator)
{
return $validator->requirePresence('my_field', 'create', 'Custom error message');
}
Data being set:
['my_field' => null]
As far as I can tell from the docs, this should not fail validation.
Key presence is checked by using array_key_exists() so that null values will count as present.
However, what is actually happening is that validation is failing with a message:
'my_field' => 'This field cannot be left empty'
This is Cake's default message for the notEmpty() validation function, so where is it coming from? I want it to allow the null value. My database field also allows NULL.
Edit
I have managed to solve the issue by adding allowEmpty() to the validation for that field. This would, therefore, seem to show that Cake assumes that if your field is required you also want it validate notEmpty() by default, even if you didn't tell it so.
This directly contradicts the documentation line I showed above:
Key presence is checked by using array_key_exists() so that null values will count as present.
So does the documentation need to be updated, or is it a bug?
Although it is not mentioned in the Cake 3 documentation, required fields are not allowed to be empty by default, so you have to explicitly state that the field is required and allowed to be empty.
public function validationDefault(Validator $validator)
{
return $validator
->requirePresence('my_field', 'create', 'Custom error message')
->allowEmpty('my_field', 'create');
}
This had me stumped for a while. The default behaviour is not at all intuitive. Here's some code that applies conditional validation on an array of scenarios coded as [ targetField, whenConditionalField, isConditionalValue ]
public function validationRegister()
{
$validator = new Validator();
$conditionals = [ ['shipAddress1','shipEqualsBill','N'], ['shipTown','shipEqualsBill','N'], ['shipPostcode','shipEqualsBill','N'] ];
foreach($conditionals as $c) {
if (!is_array($c[2])) $c[2] = [$c[2]];
// As #BadHorsie says, this is the crucial line
$validator->allowEmpty($c[0]);
$validator->add($c[0], 'notEmpty', [
'rule' => 'notEmpty',
'on' => function ($context) use ($c) {
return (!empty($context['data'][$c[1]]) && in_array($context['data'][$c[1]], $c[2]));
}
]);
}
return $validator;
}
So, in this case, if the user selects that the Shipping Address is not the same as the Billing Address, various shipping fields must then be notEmpty.

Validator - return all error messages

Currently the Validator in Laravel only appears to return one error message per field, despite the field potentially having multiple rules and messages. (Note: I'm currently passing an empty array as $data to Validator::make)
What I'm trying to do is build an array of each field's rules and messages that could potentially be re-used for front end validation. Something like this:
{
"name": {
"required": [
"The name field is required."
],
"max:255": [
"The name field may not be greater than 255."
]
},
"email": {
"required": [
"The email field is required."
],
"email": [
"The email field must be a valid email address."
],
"max:255": [
"The email field may not be greater than 255."
]
}
}
The getMessage method in Illuminate\Validation\Validator looks like it would get me close to being able to construct something myself, however it is a protected method.
Does anyone know of a way to get a Validator instance to output all rules and messages?
Currently the Validator in Laravel only appears to return one error message per field, despite the field potentially having multiple rules and messages.
Validation of given field stops as soon as a single validation rule fails. That's the reason you're getting only single error message per field.
As of fetching the validation messages like in the example you provided, Laravel's validator does not provide such option, but you could easily achieve that by extending the Validator class.
First, create your new class:
<?php namespace Your\Namespace;
use Illuminate\Validation\Validator as BaseValidator;
class Validator extends BaseValidator {
public function getValidationMessages() {
$messages = [];
foreach ($this->rules as $attribute => $rules) {
foreach ($rules as $rule) {
$messages[$attribute][$rule] = $this->getMessage($attribute, $rule);
}
}
return $messages;
}
}
As you can see the output is a bit different than your example. There is no need to return an array of messages for given attribute and rule, as there will be always only one message in the array, so I'm just storing a string there.
Second, you need to make sure that your validator class is used. In order to achieve that, you'll need to register your own validator resolver with Validator facade:
Validator::resolver(function($translator, array $data, array $rules, array $messages, array $customAttributes) {
return new \Your\Namespace\Validator($translator, $data, $rules, $messages, $customAttributes);
});
You can do this in your AppServiceProvider::boot() method.
Now, in order to get validation messages for given validator, you just need to call:
Validator::make($data, $rules)->getValidationMessages();
Keep in mind this code hasn't been tested. Let me know if you see any issues or typos with the code and I'll be more than happy to get that working for you.

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