Laravel replace variable on Model - php

I would like to be able to override a variable on the model, so that a normal field is instead replaced by a relationship's field, i.e.
Where product.image might normally be a field, I want to run a function which will go through all of the resulting products from a query and replace the image field with something like the following --
(Product.php) Model
...
public function variantImages(){
return $this->image = $this->variants()->first()->pluck('image_url');
}
...
So the default product image field is replaced by the "first product variant's image". I don't want to do this in a collection once I have already got the data, the problem here is being able to do this at a Model level.
Is there a way to do this within a scope?

You can create an accessor instead of a normal function:
// Singular because it only gets one
public function getVariantImageAttribute(){
return $this->image = $this->variants()->first()->pluck('image_url');
}
This will make it available under $product->variant_image
Then you can ensure it is always appended to your model (if you want) by adding it to the appends e.g.:
$appends = [ 'variant_image' ];
Since this is not the best idea since it will force load the relationship every time you get a product (even if you didn't request it) you can conditionally control when to append it via e.g.:
return response()->json($product->append('variant_image'));
Note that the append method also works for collecitions of eloquent models.

Related

Does a one-to-one relationship in Laravel always need first()?

I have a one-to-one relationship between User and UserSettings models,
But (after $user = auth()->user()) when I try $user->settings()->something it throws an Undefined property error.
It's gone when I use $user->settings()->first()->something...
My question is, is this how it's supposed to work? or am I doing something wrong?
You cannot directly run $user->settings()->something.
Because when you call $user->settings(), it just return Illuminate\Database\Eloquent\Relations\HasOne object.
So it is not the model's object, you need to take the model's object and call its attribute like this.
$user->settings()->first()->something;
Dynamic Properties
Since you have one-to-one relationship between User and UserSettings.
If you have a one-to-one relationship in your User model:
public function settings()
{
return $this->hasOne('App\Models\UserSettings', 'user_id', 'id');
}
According to Laravel doc
Once the relationship is defined, we may retrieve the related record using Eloquent's dynamic properties. Dynamic properties allow you to access relationship methods as if they were properties defined on the model:
Eloquent will automatically load the relationship for you, and is even smart enough to know whether to call the get (for one-to-many relationships) or first (for one-to-one relationships) method. It will then be accessible via a dynamic property by the same name as the relation.
So you can use eloquent's dynamic properties like this:
$user->settings->something; // settings is the dynamic property of $user.
This code will give you a result of collection.
$user->settings;
So calling 'something' is not available or it will return you of null, unless you get the specific index of it.
$user->settings()->something
while this one works because you used first() to get the first data of collection and accessed the properties of it .
$user->settings()->first()->something
The first method returns the first element in the collection that passes a given truth test
see docs here laravel docs
If you want to get the user settings itself simply do this:
$user->settings
Then you can get the fields of the settings doing this:
$user->settings->something
When you do this $user->settings() you can chain query after that. E.g.
$user->settings()->where('something', 'hello')->first()
That's why the output of $user->settings and $user->settings()->first() are the same.
Auth only gives you user info;
Try the following code:
$user = User::find(auth()->user()->id);//and then
$user->settings->something;

How to incorporate ->isDirty() with laravel ->update()

I want to check if certain columns in database are changed.
the update code in my controller goes like this:
$tCustomer = TCustomer::withTrashed()->findOrFail($id);
$tCustomer->update(request()->all());
How do I incorporate it with the ->isDirty() function?
I tried adding it after $tCustomer->update(request()->all()); but it always returns false:
$dirty = $tCustomer->getDirty('payment_method_id');
do I have to add isDirty() before or right after the update?
You can uuse fill() instead of update(), check for isDirty(), then save(). This way you can take advantage of the mass injectable fields.
$myModel->fill($arrayLikeinUpdate);
if ($myModel->isDirty()) {
// do something
}
$myModel->save();
You have to use observers, you can use updating() eloquent model event for before saving the model or updated() after saving model, you just have to add below code in your TCustomer model:
public static function boot(){
static::updated(function($tCustomer){
if($tCustomer->isDirty('field_name')){
//This code will run only after model save and field_name is updated, You can do whatever you want like triggering event etc.
}
}
static::updating(function($tCustomer){
if($tCustomer->isDirty('field_name')){
//This code will run only before saving model and field_name is updating, You can do whatever you want like triggering event etc.
}
}
isDirty returns a bool, so you'd use it with a conditional to check if a given models attributes have changed. Example:
// modify an attribute
$myModel->foo = 'some new value';
....
// do other stuff
...
// before the model has been saved
if ($myModel->isDirty()) {
// update model
$myModel->save();
}
So the check needs to be done before you update (save) the model.
Calling update saves the model with the given attributes in one call so you wouldn't use isDirty in that context.

Eager load model using with but giving it another name - Laravel 5.2

Is it possible to use eager loading using the with method but giving it another name? Something like:
->with('documents as product', 'documents.documents as categories')
I have a documents table that can be product or categories, eager loading is working but not that friendly to retrieve the documents by just the document name instead of what it really is.
This feature is currently not supported in any Laravel version. Your best bet is to duplicate your relations and name them according to your needs. E.g.:
class Post extends Model
public function documents() {
return $this->hasMany(Document::class);
}
public function products() {
return $this->hasMany(Document::class)
->where('type', 'product'); // Scope the query, if necessary
}
public function categories() {
return $this->hasMany(Document::class)
->where('type', 'category'); // Would a Document really be of type 'category', though? Looks like a code smell.
}
}
$postsWithAllDocs = Post::with('documents')->get();
$postsWithProductsOnly = Post::with('products')->get(); // Only eager load Documents of type 'product'
On a side note, you mention that a Document can be a product or category, which logically doesn't seem to make much sense. Part of the issue could probably be resolved by rethinking the structure of your database and relations.
Eager loading tells "load also this relationship data", so next you can access subject->relation without further queries
if you want to rename the relationship maybe you should do it renaming the relationshp in the model, not in the eager loading
you can also bypass this by adding virtual attributes:
function getProductAttribute(){
return $this->document;
}
leaving eager loading on original document
resulting in product attribute that is the same as document:
$subject->product === $subject->document
I asked myself the same question, and since I didn't find a satisfying answer online, here is what I did.
I had:
$o->load('X');
but I wanted the $o object to have attribute Y with the value of X relation. Since I already had the Y relation defined for $o, I couldn't rename X to Y and finish the job. So I did
$o['Y'] = $o->X();
I know this is not the best solution, but it works for my case :)
Note: load and with produce exactly the same number of sql queries - you need to choose the one which is more appropriate for your situation.

How to make models use defaults in Phalcon PHP Framework?

If a table has defaults on certain fields and NULL is not allowed, one would expect the insert script to use those defaults, as MariaDB/MySQL usually does. For example, if the table products has an AI field "id", a required field "name" and two required fields "active" and "featured" which both default to 1, then the query
INSERT INTO products (name) VALUES ('someName');
automatically inserts 1 as the value of active and featured. However, when using Phalcon's models like so:
$product = new Products();
$product->setName('someName');
$product->save();
returns validation errors saying "active" and "featured" are required.
Is there a flag I should provide during model generation in order for Phalcon tools to harvest and input the defaults into Model classes, or another way to make Phalcon automatically use defaults if found? Best approach would be just ignoring the fields that weren't set, I reckon. Can I make the models do that?
You can use a raw database value to avoid that, in specific inserts:
<?php
use Phalcon\Db\RawValue;
$product = new Products();
$product->setName('someName');
$product->setType(new RawValue('default')); //use default here
$product->save();
Or, general before create/update for specific fields:
use Phalcon\Db\RawValue;
class Products extends Phalcon\Mvc\Model
{
public function beforeValidationOnCreate()
{
$this->type = new RawValue('default');
}
}
Or ignore these fields in every SQL INSERT generated:
use Phalcon\Db\RawValue;
class Products extends Phalcon\Mvc\Model
{
public function initialize()
{
$this->skipAttributesOnCreate(array('type'));
}
}
Although I find twistedxtra's answer fascinating from the aspect that Phalcon contains this wicked method to read the column default, I believe from a architectural point of view this might be the wrong approach as you rely on your database to define the defaults of the properties of your model.
I would set the default value when declaring the property and keep the logic in the application layer. But that's just me.
Use Like below
The skipAttributesOnCreate will make sure Phalcon does not attempt to put a a value in that column. The database will apply the default value.
public function initialize()
{
$this->setSource('table_name');
$this->skipAttributesOnCreate(['name_of_column']);
}

Implementing a custom getter in Yii?

I am working with Yii and I have the following situation:
I have a MySQL table:
charges {
id INT AUTOINCREMENT,
name VARCHAR(256),
value DOUBLE
}
Then I have the model from this table. And finally I have the views for create, list, admin, update and view.
In the admin and view views I want to display the value field formated with two decimal numbers. One option to do this could be in the view and admin files format the number. Is there a way to create a method in the model and then not having to do anything in the views but the method itself will solve formating the number?
thanks
You can override the afterFind() method of CActiveRecord in your model and format the value field in it.
Alternatively you could also declare a virtual attribute of the model, and set it in the afterFind() method, and use this virtual attribute in the views.
Example(with virtual attribute):
Class ChargesModel extends CActiveRecord{
public $valueModified;
/*
* other code
*/
protected function afterFind(){
parent::afterFind();
// in the following line i'm just making $valueModified and $value equal, but obviously you would have to insert the 2 decimals
$this->valueModified=$this->value;
}
}
Then you can access the virtual attribute like this : $modelObject->valueModified
I would recommend you to use the virtual attribute, because you then have both the unmodified $value and modified $modifiedValue, once the formatting is done, we can use either as required, and not have to reformat back to original when we need the original.

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