Laravel: How to dynamically create and name views? - php

Question

I am making a website for college administration where professors log in and assign marks to the students they are teaching.
There's a table, called "IA_Marks" in my database:
|Student_ID|Subject_Code|Name|Marks1|Marks2|Marks3|Semester|Division|
There's also a table called "Classroom_Mapper" in my database, that helps map a professor to a classroom, with a subject:
|Prof_ID|Subject_Code|Semester|Division|
This is a method in my controller:
public function showTable(){
$sem = DB::table('classroom_mappers')->where('Prof_ID', auth()->user()->PID)->pluck('semester');
$division = DB::table('classroom_mappers')->where('Prof_ID', auth()->user()->PID)->pluck('division');
$data = DB::table('iamarks')->where([['semester','=',$sem],['division','=',$division]])->get();
return view('ia',compact('data'));
}
Using this, I can fetch rows that belong to the professor who has logged in.
But, there's a problem.
Say the professor teaches two subjects, in two semesters. Then, the where clause will return multiple results from the mapper table.
For example:
select semester from classroom_mapper where Prof_ID=auth()->user()->Prof_ID
output:
8
5
Then the students from both 5th and 8th semester will be shown on his dashboard. Our target semester was, say 5th. Then it'll be a problem.
Registering for a subject, is done as shown here:
form screenshot
Let's call the subject being registered in the screenshot "SUBJECT 4".
It is a subject for the 5th semester, division A.
I want to dynamically make a button(SUBJECT 4) on the dashboard, which when clicked, sends the semester(5) and division(A) of choice to the controller.
Dashboard Screenshot
This button should open a newly made page with name of the subject(subject4.blade.php), where the database table contents for target semester and division(5 and A) will be shown.
How do I make this dynamic view creating button which sends specific info to controller? Is it even possible?

Answer 1

There are a few ways to do this with Laravel, but my goto is usually to create a single blade template for each view (dashboard, subject, etc.) that can be dynamically populated -- assuming that the layout for each subject view is the same.
In your dashboard view, you could generate a url for each button that uses a format like this: http://cas.jce.in/subject/semester/5/division/a/
Next, create a route that uses a couple of paramaters, something like this:
Route::get('/subject/semester/{semester_id}/division/{division_id}', 'ControllerName#showSubject');
More info here: https://laravel.com/docs/5.8/routing#required-parameters
Then in your controller, add a showSemester function like this:
function showSubject($semester_id, $division_id){
$data = DB::table('table_name')->where('semester', '=', $semester_id)->where('division', '=', $division_id)->first();
return view('subject', ['data'=>$data, 'semester'=>$semester_id, 'division'=>$division_id]);
}
Your route parameters are available to the controller, in order of appearance. So we can add $semester_id and $division_id as the first two parameters of our function. Next, we'll to the database work to retrieve the data we need before returning everything to a view.
Note here that we're using a single view rather than dynamically selecting one. You could create individual views for each subject, but im thinking you probably don't need to unless the layout of each one is unique in some way. In that case, you can simply do something like this, but I'd generally try to avoid it.
$view = 'subject'.$data->subject_id;
return view($view, ['data'=>$data, 'semester'=>$semester_id, 'division'=>$division_id]);
Also, just a quick note ... you may consider adjusting your database queries from above to use a select statement rather than pluck. The end result is the same, but using a select can boost performance by only loading the data you want ... rather than loading everything up front and throwing most of it away.
$sem = DB::table('classroom_mappers')->where('Prof_ID', Auth()->user()->PID)->pluck('semester');
... becomes ...
$sem = DB::table('classroom_mappers')->select('semester')->where('Prof_ID', auth()->user()->PID)->get();