Call to a member function follow() on integer
Stefan Bogdanescu
Founder & Senior Architect · 2026-06-29
# Call to a member function follow() on integer: Debugging Eloquent Relationship Errors
As a senior developer working with Laravel, you frequently encounter frustrating errors when dealing with Eloquent relationships and data manipulation. One common pitfall involves attempting to call methods on variables that hold primitive types, such as integers, instead of full Model instances. This is precisely what leads to the error: `Call to a member function follow() on integer`.
This post will diagnose why this error occurs in the context of implementing a user following system and provide the correct, robust solution using Laravel's Eloquent features.
---
## Understanding the Error: Why Integers Cause Trouble
The error `Call to a member function follow() on integer` is fundamentally a type mismatch error. In Object-Oriented Programming (OOP), you can only call methods (functions) on objects, not on primitive types like integers or strings.
In your scenario, this error happens because somewhere in your controller logic, you are retrieving an ID (an integer) and attempting to treat it as if it were a full `$user` object when calling the relationship method, such as `$user->follow($otherUser->id)`. The code expects `$user` to be an instance of the `User` model, but it is receiving only its primary key.
## Analyzing the Follow Logic Implementation
Let's look at the code snippets you provided to pinpoint where the logic breaks down:
**The Controller Snippet:**
```php
public function store()
{
$user1 = Auth::user()->id; // $user1 is an integer (e.g., 5)
$user2 = Input::get('id'); // $user2 is the ID of the user being followed
$user1->follow($user2); // ERROR: Trying to call follow() on an integer!
return redirect()->to(action('HomeController@index'));
}
```
The issue lies in how you initialize `$user1`. If you retrieve only `Auth::user()->id`, `$user1` is just the ID. You need to fetch the full Eloquent model instance before attempting to call methods defined on that model (like `follow()` or `unfollow()`).
## The Solution: Eager Loading and Model Retrieval
The fix involves ensuring that you are working with actual Eloquent models when manipulating relationships. This is a core principle in building scalable applications, especially when dealing with many-to-many relationships, which Laravel excels at managing (as detailed in resources like the official [Laravel documentation](https://laravelcompany.com)).
### 1. Correctly Fetching User Models
Instead of storing just the ID, you must retrieve the full model instance:
```php
public function store()
{
// Retrieve the authenticated user as an Eloquent Model
$follower = Auth::user();
// Retrieve the target user ID from input
$targetUserId = Input::get('id');
// Now, find the target user model instance
$followedUser = \App\Models\User::findOrFail($targetUserId);
// Proceed with the relationship logic using actual models
$follower->follow($followedUser);
return redirect()->to(action('HomeController@index'));
}
```
### 2. Reviewing Eloquent Methods (Model Side)
Your methods defined on the `User` model look structurally correct for a many-to-many relationship:
```php
function followers()
{
// Defines the relationship to the 'followers' pivot table
return $this->belongsToMany('App\User', 'followers', 'user_id', 'follower_id');
}
function follow(User $user) {
// This method correctly uses the relationship defined above to attach a pivot record.
$this->followers()->attach($user->id);
}
function unfollow(User $user) {
// Correctly detaches the pivot record.
$this->followers()->detach($user->id);
}
```
These methods are correct because they operate on the `$this` object, which is an Eloquent model, allowing access to the defined relationships.
## Conclusion
The error `Call to a member function follow() on integer` is a classic symptom of mistaking a database ID for an Eloquent Model object. By ensuring that you retrieve full User models from the database (using methods like `findOrFail()` or casting retrieved results) before attempting to call relationship methods, you resolve this type mismatch. Always treat your data as Eloquent objects when working with relationships in Laravel; this approach makes your application more readable, maintainable, and error-resistant. For deeper dives into Eloquent patterns, always refer back to the official documentation at [laravelcompany.com](https://laravelcompany.com).