How can I chain ->makeHidden() when eager-loading a belongsToMany relationship? - laravel

Does anyone have any suggestions for how to use makeHidden() when eager-loading? here is my code:
$work=Work::with([
'work_category'=>function($query){
$query->with(['companies'=>function($query){
$query->select('companies.id','companies.name');
}]);
},
'prices',
])
->findOrFail($id);
Work has a belongsTo('App\WorkCategory') relationship, and WorkCategory has a belongsToMany('App\Company') relationship through a pivot.
If I try to chain ->makeHidden('pivot') on to $query->select('companies.id','companies.name'); - I get a BadMethodCall exception: Call to undefined method Illuminate\Database\Eloquent\Relations\BelongsToMany::makeHidden()
Is there something I'm missing here?
This is the code with the offending makeHidden() call
$work=Work::with([
'work_category'=>function($query){
$query->with(['companies'=>function($query){
$query->select('companies.id','companies.name')->makeHidden('pivot');
}]);
},
'prices',
])
->findOrFail($id);
My temporary fix has been to add protected $hidden=['pivot']; to my Company model, however it would be nice to be able to access the pivot when I do need it, and use $model->relation->makeHidden('attribute') in my controllers to trim away extra data before sending.

Unfortunately, makeHidden() doesn't work on relationships in Laravel. Not directly nor using dot notation on the related field.
You've touched upon one solution that I've used in the past, which is to use select() to limit to only the relationship's fields that you want within the subquery as a somewhat rough way to exclude your pivot:
$query->with(['companies'=>function($query){
$query->select('id','name', 'something', 'something');
}]);
This works when the fields are limited. But its a pain when you have a lot or are making many queries.
Another alternative is to do what you've done, and mark it protected on the model: protected $hidden=['pivot'];. You then have some flexibility in various methods to use ->makeVisible('pivot'); on the fly to regain access to this pivot.

Related

Two models, two fields, return preferred if present

Been struggling with how to do this the most optimized way possible...
I have two models: Catalog and Application.
Catalog has a field called name.
Application has a field called name.
Both have a relationship with each other.
I am struggling to find a way to create a function i could use across my Laravel application which i would pass application.id to it and it would return a $app->name value based on the following logic:
if $application->name exists, use this value as the $app->name for the $application object
otherwise, get the $catalog->name value and use it as the $app->name
Note that I would like to create a component #application() where i can simply pass the $application->id and build the display logic (theming/styling) into it.
Since i display this $app->name in many places, i would like to make it as lightweight as possible to avoid unnecessary queries.
I hope this makes sense! There are probably so many ways to go with it, i am lost at figuring out the way way to do this :(
I'm not completely sure to understand your model/DB design, but you could use a custom Helper to use that function through the whole app.
For that, you can create a simple PHP class Helper.php file in app/Http/Helpers folder or whatever location you want. Something like:
<?php
use App\Catalog;
use App\Application;
if (! function_exists('getAppName')) {
function getAppName($id){
// Do your logic here to return the name
$catalog = Catalog::find($id);
return $catalog->name;
}
}
?>
Then in any controller or view, you just do
getAppName($application->id)
Do no forget to add your helpers file to the composer autoload. So in composer.json in Laravel's root folder, add the helper path to the autoload array:
"files": [
"app/Http/Helpers/helpers.php"
],
Last but not least, run the following command:
composer dump-autoload
Please note that function logic is just for sample purposes since I don't know your model structure.
In my opinion, I care about the database cost.
Use ternary expression will be elegant. But it took two times IO costs from database if application name is empty.
$app_name = Application::find($id)->name;
$app_name = empty($app_name) ? Catalog::where('application_id', $id)->first()->name;
And this will more complicated, but the catalog_query only execute when application.name is empty, it execute in database and the result is taken out only once;
And Database will only find the name from one table or two table.
Something like this:
$catalog_query = Catalog::where('catalogs.application_id', $id)->select('catalogs.name')->groupBy('catalogs.name');
// if catalogs and applications relationship is 1:1, use ->limit(1) or remove groupBy('name') is better.
Application::where("applications.id", $id)
->selectRaw("IF(application.name IS NULL OR application.name = '', (" . $catalog_query->toSql() ."), applications.name ) AS app_name")
->mergeBindings($catalog_query->getQuery())
->first()
->app_name;
Hope this will help you.

Laravel - trouble with Eloquent Collection methods such as last()

I have a variable $courses that in my debugger is shown as type App/Courses
In the model, there is a one to many relation and I retrieve these related items in the model and then access as $courses->relateditems
In the debugger, $courses->relateditems is shown as type Illuminate/Database/Eloquent/Collection
Ok, all makes sense.
I want to get last item in the $courses->relateditems collection. So I try
$courses->relateditems->last()->startdate
But this is not returning the value that I know exists. And when I evaluate the expression $courses->relateditems->last() in the debugger I get this in my laravel.log:
Symfony\Component\Debug\Exception\FatalErrorException: Cannot access self:: when no class scope is active in /app/Courses.php:68
I am just not sure what is going on. I know I can use DB queries to just get the data I need, but I have a model event triggering a function and that function receives the $courses object/model (or however we name it) and I am just trying to get this working as above.
Ideas on what I am doing wrong?
thanks,
Brian
The issue here based on the error you have at the bottom of your post is a mistake in your code.
However, I think you've misunderstood how Laravel relationships work. They essentially come in two forms on a model, that of a property and that of a method.
relateditems Is a magic property that will return the result of a simple select on the relationship if one has already been performed. If one hasn't been performed it will perform one and then return it, known as eager loading.
relateditems() Is a method that returns a query builder instance for that relationship.
By calling relateditems->last() you're loading ALL related items from the database and then getting the last, which is less than optimal.
The best thing for you to do is this:
$course->relateditems()->orderBy('id', 'desc')->first();
This will get the first item return, however, since we've ordered it by id in descending order, it'll be reversed from what could be considered its default ordering. Feel free to change the id to whatever you want.

How can I apply a status (condition) check direct to a model in laravel?

I have added a status column to my product table. Now I want that when I use Product::all() I get only the product with status is active. something like soft delete. I want that the model ignores the products that are passive until they are activated again. Is there a way to do this?
PS: I already used the model (Product::class) in tons of places. so i am looking a direct way that affects all the methods i made already. otherwise i will have to apply the solution to all the methods one by one.
If you're looking for exactly the same functionality as Soft Deletes, you can use global scopes. SoftDeletes trait uses global scope. So, if you'll apply global scope to Product model Product::all() will return all results where status = 1.
This is the best way IMO, create a scope in the model
function scopeActive($query) {
return $query->where('status', 1);
}
This way, you could do something like this
Product::active();
You can try it as:
Product::where('status', 1)->get()

Why does Laravel Controller needs (integer) cast in Homestead, but not in production server

(integer) cast must be done in Homestead for Controller parameter
I am having a hard time searching for the cause of a discrepancy between my local dev environment (Homestead) and the hosted one.
I define a route like this:
Route::get('group/{id}/data', 'GroupDataController#index');
And the code in the Controller looks like this:
public function index($id)
{
return Grouping::all()->where('group_id', $id);
}
Which works fine in production (hosted env), BUT when I execute it locally it throws and empty array [] unless I modify my Controller function to look like this:
public function index($id)
{
return Grouping::all()->where('group_id', (integer)$id);
}
I have no idea of what is going on in here, and I am tired of making changes all over my Controller to make it work on both environments.
I have searched in several place, but maybe I am using incorrect tokens for my search as I have found nothing.
Any help will be really appreciated.
The problem here is that you're not using the correct set of functions.
When you call Grouping::all(), this is actually returning an Eloquent Collection object with every record in your groupings table. You are then calling the where() method on this Collection. This causes two problems: one, it is horribly inefficient; two, the where() method on the Collection works differently than the where() method on the query builder.
The where() method on the Collection takes three parameters: the name of the field, the value in that field on which to filter, and finally a boolean value to tell it whether or not to do a strict comparison (===) or a loose comparison (==). The third parameter defaults to strict. This strict comparison is why you're having the issue you are having, but I cannot explain why one environment sees $id as an integer and the other doesn't.
The where() method on a query builder object will actually add a where clause to the SQL statement being executed, which is a much more efficient way of filtering the data. It also has more flexibility as it is not limited to just equals comparisons (the second parameter is the comparison operator for the where clause, but will default to "=" if it is left out).
You have two options to fix your issue. You can either pass in false as the third parameter to your where() method in the current code (bad), or you can update the code to actually filter using the query instead of filtering on the entire Collection (good).
I would suggest updating your code to this:
public function index($id) {
return Grouping::where('group_id', '=', $id)->get();
}
In the above code, Grouping::where('group_id', '=', $id) will generate a query builder object that has the given where clause, and then get() will execute the query and return the Collection of results.
I marked #patricus (thanks you, so much!) as the correct answer, for he really pointed me in the right direction to understand that there are some keywords that work differently under different contexts (like get()), but I will also point out, how my 2 confusing points were solved in my case:
The difference in my code between production and Homestead development environments was solved by pointing my Homestead to the production database. I am not sure what was the difference (maybe collation or table format), but it gave me a quick out.
I was trying to filter a list of elements in the database but I was constructing it with the wrong logic for Laravel.
To clear what I refer to in the second point, I was using this code:
Grouping::all(['id', 'name_id', 'product_id', 'ship_id'])->where('name_id', '=', $id);
I thought this could work, because it would be selecting all items, with the selected columns, and then filter those with a where clause. But I was wrong, since, as I found out later, the correct way of writing this is:
Grouping::where('name_id', $id)->select('id', 'name_id', 'product_id', 'ship_id')->get();
This is because I forgot completely that I was assembling the query, not writing the actions I expected the program to do.
This second syntax has more logic, since I specify the filter, then put the columns over what was filtered, and finally execute the query with the get() clause.
Of course, it can also be written the other side around for clearer fluent reading:
Grouping::select('id', 'name_id', 'product_id', 'ship_id')->where('name_id', $id)->get();

How to retrieve a customised list of records according to Repository pattern?

I wanna move the business logic out of controller actions. I read a lot about repository pattern in laravel with tons of examples.
However they're usually pretty straightforward - we have a class that uses some repository to fetch a list of all possible records, the data is returned to the controller and passed to the view.
Now what if our list isn't all the possible records? What if it depends on many things. For example:
we display the list as "pages" so we might need X records for Y-th page
we might need to filter the list or even apply multiple filters (status, author, date from - to etc)
the user can change the sorting of the data (for example by clicking the table column titles)
we might need some data from other data sources (joined tables) or it might even be used for sorting (so lazy loading won't work)
Should I write a special method with all these cases in mind? Something like that:
public function getForDisplay(
$with = array(),
$filters = array(),
$count = 20,
$page = 0,
$orderBy = 'date',
$orderDir = 'DESC'
)
{
//all the code goes here
return $result;
}
And then call it like this from my controller:
$orders = $this->orders->getForDisplay(
array('customer', 'address', 'seller'),
Input::get('filters', array()),
20,
Input::get('page', 0),
Input::get('sort', 'date'),
Input::get('direction', 'DESC')
);
This looks wrong already and we didn't even get to the repositories yet.
What are the best/correct practices for solving situations like this? I'm pretty sure there has to be a way to achieve the desired results without adding all the possible combinations as a method arguments.
Use the repository pattern just for business model updates and you'll end up with very specific query methods (the Domain usually doesn't need many queries and they are pretty straightforward). For UI/reporting querying purposes, you can use a simple DAO/Service/ORM/QUery Handler , that will take some input and returns the desired data (at least part of the view model).
Since you're already using an ORM, you can use it directly. Note that you can use the ORM for domain updates also, but inside a repository's implementation i.e the app only sees the repository interface. We care about separation at the business layer, for UI querying you can skip the unneeded abstraction.
Btw, because we're talking about design, everything is subjective and thus, there's no single best/optimum way of doing things.

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