CODEWITHSUNDEEP
laraveleloquenteager-loading
Muhammad Saeed Paracha
Muhammad Saeed Paracha

Reputation: 86

Laravel Dynamic Eager Loading for Dynamic Relationships

Scenario:

I have a SaaS application that has flexible database structure, so its fields are bound to change, especially given it has a Json field (for any extra database structure to be created from client side of the application), including relationship based fields. so Account Table can have dynamically created employee_id field, and thus the need to access relationships dynamically

Problem:

I need to EagerLoad models based on this dynamic relationship. If I had something like this:

// Account Model
public function employee(){
    return $this->belongsTo(App\Employee);
}

it would be easy. But what I have is this:

public function modelBelongsTo(){
    return $this->belongsTo($dynamicClassName, $dynamicForeignKey);
}

Now if I eager load this, I'll get Account Model instance with related Employee on key modelBelongsTo. This is how Eloquent Names based on the function of eagerload. But after this I cannot use this function again to eagerload a second model because it'll just overwrite results on modelBelongsTo key.

Possible Solution Directions:

1) Can I Somehow change laravel's process to use a name I provide?

or

2) Can I write functions on the fly to overcome this so I'll write employee function on the fly?

or

3) Worst Case Scenario: I iterate over all records to rename their keys individually because I am using a pagination, it wouldn't that big of a deal to loop over 10 records.

Upvotes: 6

Views: 1024

Answers (1)

whizboy
whizboy

Reputation: 49

Us a morph relationship define the various dynamic classnames say

Employee
Boss

Morph works by having the related key and the table name stored in the parent table, it means to relate them you have to use a join or an orm and you cant have foreign key constraint on it as it links to different tables.

then have your account have morphs where we have

Account

as top class then we have

EmployeeAccount, BossAccount

which have their relation to boss and employee

then in Account have morphto relation call it specificAccount() to which in its child morphs have the morph relation to Account

then add it to $with so to eager load them so when fetching account you could simply do

$account ->specificAccount

to get its morph child. which is nullable

This is totally dynamic such that if you have other classes in future you can just add and add the morph relationship. This may be applied to any reflection or runtime evaluated and loaded classes/code though it is not advisable to do this, as you can always edit code to create new functionality without affecting previous.

Upvotes: 0

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