laravel 5.1 BelongsTo Reverse call - php

What i know:
$this->$parent->childs(); //we get childs data
what i want to know how:
$this->child->find($id)->parent(); //how to get childs parent without including model in controller | by just using eloquent
heres my sample code of employee and employeeDependent model:
trait EmployeeRelationships{
public function dependents(){
return $this->hasMany(\App\DB\EmployeeDependent\EmployeeDependent::class);
}
}
trait EmployeeDependentRelationships{
/**
* #return mixed
*/
public function employee(){
return $this->belongsTo(\App\DB\Employee\Employee::class, 'employee_id');
}
}

If you want to get the reverse of a BelongsTo relationship you need to specify the inverse of the relationship on the corresponding model. For example:
Employee Class
class Employee extends Model
{
public dependents()
{
return $this->hasMany(Dependant::class);
}
}
Dependent Class
class Dependent extends Model
{
public employee()
{
return $this->belongsTo(Employee::class, 'employee_id');
}
}
With these relationships defined you can then access the relevant models by calling the appropriate methods like so:
$dependents = Employee::first()->dependents; // Returns an eloquent collection
$employee = Dependent::first()->employee; // Returns a model of type Employee
Note that in this example using the first() method to grab a model, you can can do this with any object of the correct type.

Related

Laravel hasOne relation with where clause

I have a model called RealEstate, this model has a relation with another model called TokenPrice, I needed to access the oldest records of token_prices table using by a simple hasOne relation, So I did it and now my relation method is like following:
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\HasOne;
class RealEstate extends Model
{
public function firstTokenPrice(): HasOne
{
return $this->hasOne(TokenPrice::class)->oldestOfMany();
}
}
By far it's fine and no complexity. But now, I need to involve another relation into firstTokenPrice.
Let me explain a bit more:
As my project grown, the more complexity was added it, like changing firstTokenPrice using by a third table called opening_prices, so I added a new relation to RealEstate called lastOpeningPrice:
public function lastOpeningPrice(): HasOne
{
return $this->hasOne(OpeningPrice::class)->latestOfMany();
}
So the deal with simplicity of firstTokenPrice relation is now off the table, I want to do something like following every time a RealEstate object calls for its firstTokenPrice:
Check for lastOpeningPrice, if it was exists, then firstTokenPrice must returns a different record of token_price table, otherwise the firstTokenPrice must returns oldestOfMany of TokenPrice model.
I did something like following but it's not working:
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\HasOne;
class RealEstate extends Model
{
public function lastOpeningPrice(): HasOne
{
return $this->hasOne(OpeningPrice::class)->latestOfMany();
}
public function firstTokenPrice(): HasOne
{
$lop = $this->lastOpeningPrice;
if ($lop) {
TokenPriceHelper::getOrCreateFirstToken($this, $lop->amount); // this is just a helper function that inserts a new token price into `token_prices` table, if there was none exists already with selected amount
return $this->hasOne(TokenPrice::class)->where('amount', $lop->amount)->oldestOfMany();
}
return $this->hasOne(TokenPrice::class)->oldestOfMany();
}
}
I have checked the $this->hasOne(TokenPrice::class)->where('amount', $lop->amount)->oldestOfMany() using by ->toSql() method and it returns something unusual.
I need to return a HasOne object inside of firstTokenPrice method.
You can use ofMany builder for that purpose:
public function firstTokenPrice(): HasOne
{
$lop = $this->lastOpeningPrice;
if ($lop) {
TokenPriceHelper::getOrCreateFirstToken($this, $lop->amount); // this is just a helper function that inserts a new token price into `token_prices` table, if there was none exists already with selected amount
return $this->hasOne(TokenPrice::class)->ofMany([
'id' => 'min',
], function ($query) use ($lop) {
$query->where('amount', $lop->amount);
});
}
return $this->hasOne(TokenPrice::class)->oldestOfMany();
}
I used ->oldest() with a custom scope called amounted in TokenPrice model:
class TokenPrice extends Model
{
public function scopeAmounted(Builder $query, OpeningPrice $openingPrice): Builder
{
return $query->where('amount', $openingPrice->amount);
}
/....
}
And then changed my firstTokenPrice
public function firstTokenPrice(): HasOne
{
$lop = $this->lastOpeningPrice;
if ($lop) {
TokenPriceHelper::getOrCreateFirstToken($this, $lop->amount);
return $this->hasOne(TokenPrice::class)->amounted($lop)->oldest();
}
return $this->hasOne(TokenPrice::class)->oldestOfMany();
}
It's working, but I don't know if it's the best answer or not

Hide foreign id column in an Eloquent relationship

Let's consider the Einstein's Puzzle and these two models:
class Pet extends Eloquent
{
public function pet()
{
return hasOne(Man::class)
}
}
class Man extends Eloquent
{
public function pet()
{
return belongsTo(Pet::class)
}
}
If I want to get all the Pets:
Pet::all()->toArray();
I'll get for instance:
{
id: 2,
man: {
nationality: "German",
pet_id: 2
}
name: "Fish"
}
Having the pet_id column is irrelevant in that case and I would like to hide it. How?
Use Eloquent API Resources to get an array version of your Models. This is more flexible in the long run than relying on the toArray method of the model which will not be configurable.
If you still want to use toArray, you can simply add the attributes that should not be included to a protected member variable called $hidden in each corresponding model (See documentation about serialization of Eloquent models).
class Pet extends Eloquent
{
public function pet()
{
return hasOne(Man::class)->select('nationality');
}
}

Retrieving all morphedByMany relations in Laravel Eloquent

In the Laravel documentation, there is the following example for retrieving morphedByMany relations, which are many-to-many polymorphic relations.
Laravel Many to Many polymorphic relations documentation
namespace App;
use Illuminate\Database\Eloquent\Model;
class Tag extends Model
{
/**
* Get all of the posts that are assigned this tag.
*/
public function posts()
{
return $this->morphedByMany('App\Post', 'taggable');
}
/**
* Get all of the videos that are assigned this tag.
*/
public function videos()
{
return $this->morphedByMany('App\Video', 'taggable');
}
}
How would I get a list of all morphed relations in one query / collection, for instance, posts and videos, and then if I later added photos (or anything), that too?
I use a trick here:
Create a Model Taggable for your connection table taggable and add a hasMany relation to the Tag model.
public function related()
{
return $this->hasMany(Taggable::class);
}
Within your Taggable model create a morphedTo relation.
public function taggables()
{
return $this->morphTo();
}
Now you can get all models which are using the tag by calling:
$tagged = Tag::with('related.taggables');
Did you think to use the "union" function of the collections to merge all the different collection in order to retrieve all what you need?
class Tag extends Model
{
[...]
/**
* Get all of.
*/
public function morphed()
{
return $this->video->union($this->posts)->all();
}
}
You should be able to add a relationship on your Tag class as such
public function taggable()
{
return $this->morphedTo();
}
That will use the taggable_id and taggable_type to get the relevant Model that it is tied to.

Accessors (Getter) & Mutators (Setter) On a Pivot Table in Laravel

I have a pivot table that connects users to workspaces. On the pivot table, I also have a column for role, which defines the users role for that workspace. Can I provide Accessor (Getter) & Mutator (Setter) methods on the role inside the pivot table? I have been trying to look all over, but details on pivot tables in eloquent are pretty sparse.
I am not sure if I have to setup a custom pivot model? If I do, an example would be awesome as the documentation on pivot models is very basic.
Thanks.
If all you need to do is access additional fields on the pivot table, you just need to use the withPivot() method on the relationship definition:
class User extends Model {
public function workspaces() {
return $this->belongsToMany('App\Models\Workspace')->withPivot('role');
}
}
class Workspace extends Model {
public function users() {
return $this->belongsToMany('App\Models\User')->withPivot('role');
}
}
Now your role field will be available on the pivot table:
$user = User::first();
// get data
foreach($user->workspaces as $workspace) {
var_dump($workspace->pivot->role);
}
// set data
$workspaceId = $user->workspaces->first()->id;
$user->workspaces()->updateExistingPivot($workspaceId, ['role' => 'new role value']);
If you really need to create accessors/mutators for your pivot table, you will need to create a custom pivot table class. I have not done this before, so I don't know if this will actually work, but it looks like you would do this:
Create a new pivot class that contains your accessors/mutators. This class should extend the default Pivot class. This new class is the class that is going to get instantiated when User or Workspace creates a Pivot model instance.
namespace App\Models;
use Illuminate\Database\Eloquent\Relations\Pivot;
class UserWorkspacePivot extends Pivot {
getRoleAttribute() {
...
}
setRoleAttribute() {
...
}
}
Now, update your User and Workspace models to create this new pivot table class, instead of the default one. This is done by overriding the newPivot() method provided by the Model class. You want to override this method so that you create an instance of your new UserWorkspacePivot class, instead of the default Pivot class.
class User extends Model {
// normal many-to-many relationship to workspaces
public function workspaces() {
// don't forget to add in additional fields using withPivot()
return $this->belongsToMany('App\Models\Workspace')->withPivot('role');
}
// method override to instantiate custom pivot class
public function newPivot(Model $parent, array $attributes, $table, $exists) {
return new UserWorkspacePivot($parent, $attributes, $table, $exists);
}
}
class Workspace extends Model {
// normal many-to-many relationship to users
public function users() {
// don't forget to add in additional fields using withPivot()
return $this->belongsToMany('App\Models\User')->withPivot('role');
}
// method override to instantiate custom pivot class
public function newPivot(Model $parent, array $attributes, $table, $exists) {
return new UserWorkspacePivot($parent, $attributes, $table, $exists);
}
}
I figured out how to use Accessors and Mutators on the Pivot table (I'm using Laravel 5.8)
You must use using() on your belongsToMany relationships, for example:
namespace App;
use Illuminate\Database\Eloquent\Model;
class User extends Model {
public function workspaces() {
return $this->belongsToMany('App\Workspace')->using('App\UserWorkspace');
}
}
namespace App;
use Illuminate\Database\Eloquent\Model;
class Workspace extends Model {
public function users() {
return $this->belongsToMany('App\User')->using('App\UserWorkspace');
}
}
So, use your Pivot model:
namespace App;
use Illuminate\Database\Eloquent\Relations\Pivot;
class UserWorkspace extends Pivot {
public function getRoleAttribute() {
// your code to getter here
}
public function setRoleAttribute($value) {
// your code to setter here
}
}
This is a difficult question. The solutions I can think of are smelly and may cause some problems later on.
I am going to extend on Patricus's answer to make it work.
I was going to comment on Patricus's answer but there is simply too much to explain. To make his solution work with attach and sync we must do some ugly things.
The Problem
First let's identify the problem with his solution. His getters and setters do work but the belongsToMany relationship doesn't use the Pivot model when running sync, attach, or detach. This means every time we call one of these with the $attributes parameter the non-mutated data will be put into the database column.
// This will skip the mutator on our extended Pivot class
$user->workspaces()->attach($workspace, ['role' => 'new role value']);
We could just try to remember that every time we call one of these we can't use the second parameter to attach the mutated data and just call updateExistingPivot with the data that must be mutated. So an attach would be what Patricus stated:
$user->workspaces()->attach($workspace);
$user->workspaces()->updateExistingPivot($workspaceId, ['role' => 'new role value']);
and we could never use the correct way of passing the pivot attributes as the attach methods second parameter shown in the first example. This will result in more database statements and code rot because you must always remember not to do the normal way. You could run into serious problems later on if you assume every developer, or even yourself, will just know not to use the attach method with the second parameter as it was intended.
The Solution (untested and imperfect)
To be able to call attach with the mutator on the pivot columns you must do some crazy extending. I haven't tested this but it may get you on the right path if you feel like giving it a try. We must first create our own relationship class that extends BelongsToMany and implements our custom attach method:
use Illuminate\Database\Eloquent\Relations\BelongsToMany;
class UserWorkspaceBelongsToMany extends BelongsToMany {
public function attach($id, array $attributes = [], $touch = true)
{
$role = $attributes['role'];
unset($attributes['role']);
parent::attach($id, $attributes, $touch);
$this->updateExistingPivot($id, ['role' => $role], $touch);
}
// You will need sync here too
}
Now we have to make each Model::belongsToMany use our new UserWorkspaceBelongsToMany class instead of the normal BelongsToMany. We do this by mocking the belongsToMany in our User and Workspace class:
// put this in the User and Workspace Class
public function userWorkspaceBelongsToMany($related, $table = null, $foreignKey = null, $otherKey = null, $relation = null)
{
if (is_null($relation)) {
$relation = $this->getBelongsToManyCaller();
}
$foreignKey = $foreignKey ?: $this->getForeignKey();
$instance = new $related;
$otherKey = $otherKey ?: $instance->getForeignKey();
if (is_null($table)) {
$table = $this->joiningTable($related);
}
$query = $instance->newQuery();
return new UserWorkspaceBelongsToMany($query, $this, $table, $foreignKey, $otherKey, $relation);
}
As you can see, we are still calling the database more but we don't have to worry about someone calling attach with the pivot attributes and them not getting mutated.
Now use that inside your models instead of the normal belongsToMany:
class User extends Model {
public function workspaces() {
return $this->userWorkspaceBelongsToMany('App\Models\Workspace')->withPivot('role');
}
}
class Workspace extends Model {
public function users() {
return $this->userWorkspaceBelongsToMany('App\Models\User')->withPivot('role');
}
}
Its impossible to use setters, will not affect pivot table... make the change in the controller instead.

Updating timestamps on attaching/detaching Eloquent relations

I'm using Laravel 4, and have 2 models:
class Asset extends \Eloquent {
public function products() {
return $this->belongsToMany('Product');
}
}
class Product extends \Eloquent {
public function assets() {
return $this->belongsToMany('Asset');
}
}
Product has the standard timestamps on it (created_at, updated_at) and I'd like to update the updated_at field of the Product when I attach/detach an Asset.
I tried this on the Asset model:
class Asset extends \Eloquent {
public function products() {
return $this->belongsToMany('Product')->withTimestamps();
}
}
...but that did nothing at all (apparently). Edit: apparently this is for updating timestamps on the pivot table, not for updating them on the relation's own table (ie. updates assets_products.updated_at, not products.updated_at).
I then tried this on the Asset model:
class Asset extends \Eloquent {
protected $touches = [ 'products' ];
public function products() {
return $this->belongsToMany('Product');
}
}
...which works, but then breaks my seed which calls Asset::create([ ... ]); because apparently Laravel tries to call ->touchOwners() on the relation without checking if it's null:
PHP Fatal error: Call to undefined method Illuminate\Database\Eloquent\Collection::touchOwners() in /projectdir/vendor/laravel/framework/src/Illuminate/Database/Eloquent/Model.php on line 1583
The code I'm using to add/remove Assets is this:
Product::find( $validId )->assets()->attach( $anotherValidId );
Product::find( $validId )->assets()->detach( $anotherValidId );
Where am I going wrong?
You can do it manually using touch method:
$product = Product::find($validId);
$product->assets()->attach($anotherValidId);
$product->touch();
But if you don't want to do it manually each time you can simplify this creating method in your Product model this way:
public function attachAsset($id)
{
$this->assets()->attach($id);
$this->touch();
}
And now you can use it this way:
Product::find($validId)->attachAsset($anotherValidId);
The same you can of course do for detach action.
And I noticed you have one relation belongsToMany and the other hasMany - it should be rather belongsToMany in both because it's many to many relationship
EDIT
If you would like to use it in many models, you could create trait or create another base class that extends Eloquent with the following method:
public function attach($id, $relationship = null)
{
$relationship = $relationship ?: $this->relationship;
$this->{$relationship}()->attach($id);
$this->touch();
}
Now, if you need this functionality you just need to extend from another base class (or use trait), and now you can add to your Product class one extra property:
private $relationship = 'assets';
Now you could use:
Product::find($validId)->attach($anotherValidId);
or
Product::find($validId)->attach($anotherValidId, 'assets');
if you need to attach data with updating updated_at field. The same of course you need to repeat for detaching.
From the code source, you need to set $touch to false when creating a new instance of the related model:
Asset::create(array(),array(),false);
or use:
$asset = new Asset;
// ...
$asset->setTouchedRelations([]);
$asset->save();
Solution:
Create a BaseModel that extends Eloquent, making a simple adjustment to the create method:
BaseModel.php:
class BaseModel extends Eloquent {
/**
* Save a new model and return the instance, passing along the
* $options array to specify the behavior of 'timestamps' and 'touch'
*
* #param array $attributes
* #param array $options
* #return static
*/
public static function create(array $attributes, array $options = array())
{
$model = new static($attributes);
$model->save($options);
return $model;
}
}
Have your Asset and Product models (and others, if desired) extend BaseModel rather than Eloquent, and set the $touches attribute:
Asset.php (and other models):
class Asset extends BaseModel {
protected $touches = [ 'products' ];
...
In your seeders, set the 2nd parameter of create to an array which specifies 'touch' as false:
Asset::create([...],['touch' => false])
Explanation:
Eloquent's save() method accepts an (optional) array of options, in which you can specify two flags: 'timestamps' and 'touch'. If touch is set to false, then Eloquent will do no touching of related models, regardless of any $touches attributes you've specified on your models. This is all built-in behavior for Eloquent's save() method.
The problem is that Eloquent's create() method doesn't accept any options to pass along to save(). By extending Eloquent (with a BaseModel) to accept the $options array as the 2nd attribute, and pass it along to save(), you can now use those two options when you call create() on all your models which extend BaseModel.
Note that the $options array is optional, so doing this won't break any other calls to create() you might have in your code.

Categories