Using API to add an image to an item

[joeltoumi]

Hello!

I'm trying to use the API to upload images to my items inside a collection. I'm using /api/items/{id}/image endpoint, I have tried to build the request in different ways but I have not been able to get it to work.

This is the request I'm doing in python:

headers = {
    "Authorization": f"Bearer {token}",
    "Content-Type": "multipart/form-data"
}

url = "{api_base}/items/{item_id}/image"

with open(image_path, "rb") as img_file:
    base64_image = base64.b64encode(img_file.read())
    payload = {
        "file": base64_image
    }

    response = requests.post(url, headers=headers, data=payload)

I have tried many things and I always get this answer, I don't know if I am doing something wrong or there is some kind of bug:

{
  "@id": "/api/errors",
  "@type": "hydra:Error",
  "title": "An error occurred",
  "detail": "Unsupported operand types: array + null",
  "status": 500,
  "type": "/errors/500",
  "trace": [
    {
      "file": "/var/www/koillection/vendor/symfony/serializer/Encoder/ChainDecoder.php",
      "line": 42,
      "function": "decode",
      "class": "Api\\Encoder\\MultipartDecoder",
      "type": "->"
    },
    {
      "file": "/var/www/koillection/vendor/symfony/serializer/Serializer.php",
      "line": 386,
      "function": "decode",
      "class": "Symfony\\Component\\Serializer\\Encoder\\ChainDecoder",
      "type": "->"
    },
    {
      "file": "/var/www/koillection/vendor/symfony/serializer/Serializer.php",
      "line": 141,
      "function": "decode",
      "class": "Symfony\\Component\\Serializer\\Serializer",
      "type": "->"
    },
    {
      "file": "/var/www/koillection/vendor/api-platform/core/src/State/Provider/DeserializeProvider.php",
      "line": 88,
      "function": "deserialize",
      "class": "Symfony\\Component\\Serializer\\Serializer",
      "type": "->"
    },
    {
      "file": "/var/www/koillection/vendor/api-platform/core/src/Symfony/Security/State/AccessCheckerProvider.php",
      "line": 53,
      "function": "provide",
      "class": "ApiPlatform\\State\\Provider\\DeserializeProvider",
      "type": "->"
    },
    {
      "file": "/var/www/koillection/vendor/api-platform/core/src/Symfony/Validator/State/QueryParameterValidateProvider.php",
      "line": 38,
      "function": "provide",
      "class": "ApiPlatform\\Symfony\\Security\\State\\AccessCheckerProvider",
      "type": "->"
    },
    {
      "file": "/var/www/koillection/vendor/api-platform/core/src/Symfony/Validator/State/ValidateProvider.php",
      "line": 32,
      "function": "provide",
      "class": "ApiPlatform\\Symfony\\Validator\\State\\QueryParameterValidateProvider",
      "type": "->"
    },
    {
      "file": "/var/www/koillection/vendor/api-platform/core/src/Symfony/Security/State/AccessCheckerProvider.php",
      "line": 53,
      "function": "provide",
      "class": "ApiPlatform\\Symfony\\Validator\\State\\ValidateProvider",
      "type": "->"
    },
    {
      "file": "/var/www/koillection/vendor/api-platform/core/src/State/Provider/ContentNegotiationProvider.php",
      "line": 56,
      "function": "provide",
      "class": "ApiPlatform\\Symfony\\Security\\State\\AccessCheckerProvider",
      "type": "->"
    },
    {
      "file": "/var/www/koillection/vendor/api-platform/core/src/Symfony/Controller/MainController.php",
      "line": 82,
      "function": "provide",
      "class": "ApiPlatform\\State\\Provider\\ContentNegotiationProvider",
      "type": "->"
    },
    {
      "file": "/var/www/koillection/vendor/symfony/http-kernel/HttpKernel.php",
      "line": 178,
      "function": "__invoke",
      "class": "ApiPlatform\\Symfony\\Controller\\MainController",
      "type": "->"
    },
    {
      "file": "/var/www/koillection/vendor/symfony/http-kernel/HttpKernel.php",
      "line": 76,
      "function": "handleRaw",
      "class": "Symfony\\Component\\HttpKernel\\HttpKernel",
      "type": "->"
    },
    {
      "file": "/var/www/koillection/vendor/symfony/http-kernel/Kernel.php",
      "line": 185,
      "function": "handle",
      "class": "Symfony\\Component\\HttpKernel\\HttpKernel",
      "type": "->"
    },
    {
      "file": "/var/www/koillection/vendor/symfony/runtime/Runner/Symfony/HttpKernelRunner.php",
      "line": 35,
      "function": "handle",
      "class": "Symfony\\Component\\HttpKernel\\Kernel",
      "type": "->"
    },
    {
      "file": "/var/www/koillection/vendor/autoload_runtime.php",
      "line": 29,
      "function": "run",
      "class": "Symfony\\Component\\Runtime\\Runner\\Symfony\\HttpKernelRunner",
      "type": "->"
    },
    {
      "file": "/var/www/koillection/public/index.php",
      "line": 5,
      "function": "require_once"
    }
  ],
  "hydra:title": "An error occurred",
  "hydra:description": "Unsupported operand types: array + null"
}

I would be grateful if someone could explain briefly how to use this endpoint because I'm pretty sure I'm missing something.

[benjaminjonard]

Hello, the problem is that the endpoint isn't expecting base64 encoded files. I don't know much about Python but I think this would be the right way to do it : https://requests.readthedocs.io/en/latest/user/quickstart/#post-a-multipart-encoded-file

Hope this helps you, if not I'll try to investigate on my end

[joeltoumi]

Thanks for the quick reply!
I had also tried that way but without removing the Content-Type from the header. That's the problem! You do NOT have to specify the Content-Type header, the requests library implements it automatically.

Just in case anyone else has problems with this call, here is the correct way to do it:

headers = {
    "Authorization": f"Bearer {token}"
}

url = "{api_base}/items/{item_id}/image"

with open(image_path, "rb") as img_file:
    files = {'file': open(img_file, 'rb')}
    response = requests.post(url, headers=headers, files=files)