Laravel Eloquent query with joins and parameters - php

Question

I have a list of items (papers) and want to display all papers with a specific area.
Now i want that the user has the ability to filter the list of papers depending on different attributes.
these are the tables/models
Papers
id
name
author_id
year
paperQuality
userRating
Authors
id
name
birthDate
Paper_areas
id
paper_id
area_id
significance
Area
id
name
creationYear
I'm trying to keep Eloquent related. The user should be able to filter after papers.year, papers.paperQuality, papers.Rating, paper_areas_significance, area.creationYear
this is what i have by now
$paper_areas_query = Paper_areas::join('areas', function($join){
$join->on('areas.id', '=', 'paper_areas.area_id')
->where('areas.creationYear', '=', 2011);
});
$paper_areas_query->join('papers', function($join){
$join->on('papers.id', '=', 'paper_areas.paper_id')
->where('papers.year', '=', 2011)
->where('papers.paperQuality', '=', 4)
->where('papers.userRating', '=', 5);
});
$paper_areas_query->join('authors', function($join){
$join->on('authors.id', '=', 'papers.author_id');
});
$paper_areas_query->select('paper_areas.id', 'paper_areas.paper_id', 'paper_areas.area_id');
$paper_areas_query->orderBy('authors.name','asc');
$paper_areas_query->orderBy('papers.title','asc');
$paper_areas_query->groupBy('papers.id');
Now only papers from the year 2011 are displayed, but i'm running into 2 problems
how can i repace the year with a parameter taken from the url?
how is it possible to filter the resultset in a way that i have a collection of Paper_areas? Looking into the code above it doesn't seem to be "nice" like other code.

Answer 1

I would personally modify how you're getting your data, and instead create helper functions inside the models themselves.
In your Papers model, consider something like this:
public function fromYear($year)
{
return $this->where('year', '=', $year);
}
public function author()
{
return $this->belongsTo('Author');
}
And in your Areas model:
public function papers()
{
return $this->belongsToMany('Paper', 'Paper_areas', 'id', 'topic_id');
}
Then, with a given Area instance, you can get all of the authors for all of the papers in that area for a given year:
$id = 1;
$area = Area::find($id);
$papers = $area->papers->fromYear(2011)->get();
foreach($papers as $paper) {
$author = $paper->author;
// ...
}
As far as getting the year from a URL parameter, you can do something like this in your routes:
Route::get('/my-route/{year}', 'MyController#action');
And something like this in your controller:
class MyController
{
public function action($year)
{
$area = /** get area instance **/;
$papers = $area->papers->fromYear($year)->get();
}
}
Afterwards, hitting the route /my-route/2014 would pass the string 2014 into the action method above. You should be able to do basically the same thing for all of your other filtering requirements.