Argument 1 passed to Symfony\Component\HttpFoundation\Response::setContent() with Axios Vue and Laravel 7
Stefan Izdrail
Founder & Senior Architect · 2026-06-29
Argument 1 passed to Symfony\Component\HttpFoundation\Response::setContent() with Axios Vue and Laravel 7 - A Comprehensive Analysis
It can be confusing when encountering an error in PHP that seems unrelated to the code you have written. In this case, the error "Argument 1 passed to Symfony\Component\HttpFoundation\Response::setContent() must be of the type string or null, object given" is encountered while using Axios with Vue and Laravel 7. This blog post will guide you through troubleshooting this particular issue and provide a solution.
Firstly, let's examine the code in question. You are fetching data from an API route, `api/contacts`, and then rendering that data on your frontend using the Contacts.vue component. This seems like a straightforward process. However, the error indicates a problem with the way you are passing data between the backend and frontend.
The issue stems from Laravel's automatic JSON response conversion when using Axios with Vue. When Laravel receives an axios request, it assumes the response will be in JSON format. Therefore, it automatically converts any non-object data to a PHP object. Consequently, the error occurs because the Laravel framework is trying to set the content as an object instead of a string or null, which are valid types for this argument.
So how do you fix this problem? Fortunately, there's an easy solution: use the `JSON.stringify()` method to convert your data to JSON before passing it into Axios. This ensures that Laravel receives the data in the proper format, preventing the error from occurring. Here is a simple example of how you can achieve this:
1. Update your fetchContactList function in Contacts.vue to include `JSON.stringify()`:
```javascript
fetchContactList: function () {
console.log('Fetching contacts...');
axios
.get('api/contacts')
.then((response) => {
this.list = JSON.parse(response.data);
})
.catch((error) => {
console.log(error);
});
},
```
2. In your API routes, instead of returning an object or array, return a string with the data:
```php
Route::get('contacts', function () {
// Fetch contacts from database
$contacts = getContacts();
return json_encode($contacts);
});
```
Now, when you make an axios request, the Laravel framework will receive your data in a valid JSON format and will not generate the error. This should solve your issue and allow you to continue using Axios in conjunction with Vue and Laravel without any further complications.
In conclusion, remember that troubleshooting issues with API routes and their interactions often requires patience and careful attention to detail. By following best practices like using `JSON.stringify()` to ensure proper data formatting, you can overcome many potential issues. Keep in mind to always document your code thoroughly to aid in the debugging process if an error or unexpected behavior occurs. With these tips in mind, you'll be well-equipped to tackle any challenges that may arise while working with Laravel and its related technologies.