As soon as I move my Laravel App from MySQL to pSQL. I kept getting this error.

The Response content must be a string or object implementing __toString(), "boolean" given.

I have an API that suppose to return my promotion

http://localhost:8888/api/promotion/1

public function id($id){
    $promotion = Promotion::find($id);
    dd($promotion); //I got something here
    return $promotion;
}

It used to return my promotion, now it return an error.

dd($promotion);

I got 

Promotion {#410 ?
  #table: "promotions"
  #connection: null
  #primaryKey: "id"
  #perPage: 15
  +incrementing: true
  +timestamps: true
  #attributes: array:16 [?
    "id" => 1
    "cpe_mac" => "000D6721A5EE"
    "name" => "qwrqwer"
    "type" => "img_path"
    "status" => "Active"
    "heading_text" => "qwerq"
    "body_text" => "werqwerqw"
    "img" => stream resource @244 ?}
    "img_path" => "/images/promotion/1/promotion.png"
    "video_url" => ""
    "video_path" => ""
    "account_id" => 1001
    "img_url" => ""
    "footer_text" => "qwerqwerre"
    "created_at" => "2016-08-04 10:53:57"
    "updated_at" => "2016-08-04 10:53:59"
  ]
  #original: array:16 [?]
  #relations: []
  #hidden: []
  #visible: []
  #appends: []
  #fillable: []
  #guarded: array:1 [?]
  #dates: []
  #dateFormat: null
  #casts: []
  #touches: []
  #observables: []
  #with: []
  #morphClass: null
  +exists: true
  +wasRecentlyCreated: false
}

Content

__ Any hints / suggestions on this will be a huge help!

Your response must return some sort of Response object. You can't just return an object.

So change it to something like:

return Response::json($promotion);

or my favorite using the helper function:

return response()->json($promotion);

If returning a response doesn't work it may be some sort of encoding issue. See this article: The Response content must be a string or object implementing __toString(), \"boolean\" given."

I got this issue when I used an ajax call to retrieve data from the database. When the controller returned the array it converted it to a boolean. The problem was that I had "invalid characters" like ú (u with accent).

So, rather return the whole object first, just wrap it to json_encode and then return it. This will return a proper and valid object.

public function id($id){
    $promotion = Promotion::find($id);
    return json_encode($promotion);
}

Or, For DB this will be just like,

public function id($id){
    $promotion = DB::table('promotions')->first();
    return json_encode($promotion);
}

I think it may help someone else.

You can use json_decode(Your variable Name):

json_decode($result)

I was getting value from Model.where a column has value like this way

{"dayList":[
            {"day":[1,2,3,4],"time":[{"in_time":"10:00"},{"late_time":"15:00"},{"out_time":"16:15"}]
             },
             {"day":[5,6,7],"time":[{"in_time":"10:00"},{"late_time":"15:00"},{"out_time":"16:15"}]}
           ]
}

so access this value form model. you have to use this code.

$dayTimeListObject = json_decode($settingAttendance->bio_attendance_day_time,1);

 foreach ( $dayTimeListObject['dayList'] as $dayListArr)
 {
     foreach ( $dayListArr['day'] as $dayIndex)
     {
         if( $dayIndex == Date('w',strtotime('2020-02-11')))
         {
             $dayTimeList= $dayListArr['time'];
         }
     }
 }

 return $dayTimeList[2]['out_time'] ;

You can also define caste in your Model file.

 protected $casts = [
    'your-column-name' => 'json'
  ];

so after this no need of this line .

$dayTimeListObject = json_decode($settingAttendance->bio_attendance_day_time,1);

you can directly access this code.

$settingAttendance->bio_attendance_day_time

It is being pointed out not directly in the file which is caused the error. But it is actually triggered in a controller file. It happens when a return value from a method defined inside in a controller file is set on a boolean value. It must not be set on a boolean type but on the other hand, it must be set or given a value of a string type. It can be shown as follows :

public function saveFormSummary(Request $request) {
      ... 
      $status = true;
      return $status;
}

Given the return value of a boolean type above in a method, to be able to solve the problem to handle the error specified. Just change the type of the return value into a string type

as follows :

public function saveFormSummary(Request $request) {
      ... 
      $status = "true";
      return $status;
}