Add support for coercion by endpoints with type File

[devInterests]

If you have a remote method with a parameter that's type: 'file' you receive following error: "Error: Invalid value for argument 'file' of type 'file': [object Object]. Received type was converted to object.

As far as I understood the error is in function convertToBasicRemotingType in shared-method.js:

function convertToBasicRemotingType(type) {
  if (Array.isArray(type)) {
    return type.map(convertToBasicRemotingType);
  }
  if (typeof type === 'object') {
    type = type.modelName || type.name;
  }

  type = String(type).toLowerCase();

  switch (type) {
    case 'string':
    case 'number':
    case 'date':
    case 'boolean':
    case 'buffer':
    case 'object':
    case 'file':
    case 'any':
      return type;
    case 'array':
      return ['any'].map(convertToBasicRemotingType);
    default:
      // custom types like MyModel
      return 'object';
  }
}

The type file is supported as a separate type. The problem is that the arg is coming as type object. My fix at the moment is to use object as arg type or to use a older version where the file type is not supported and becomes default type object. But i would like to use the correct type: file.

My interface definition:

model.remoteMethod( 
       'fileUpload',
        {
            http:{ verb:'Post', source: 'body', path: '/upload/:id'},
            description: '',
            accepts: [
                {arg: 'id', type: 'string', http: { source: 'path' }, required: true},
                {arg: 'file', type: 'file', http: { source: 'body' }, required: true},
                {arg: 'req', type: 'object', http: {source: 'req'}}
            ],
            returns: {arg: 'res', type: 'object', root:true}
        });

Perhaps I am doing something wrong?

[richardpringle]

Hey @devInterests sorry about the delayed response.

The accepts.type must a LoopBack type.

I am going to close this issue for now but please feel free to carry on the conversation in here or re-open if you believe this is still an issue.

[devInterests]

Hello,

@richardpringle I was aware of the list. It seems I misunderstood this answer: Uploading images

1. We allow remote method parameters to be typed as ‘File’. If one of the parameters is typed as ‘File’, only ‘multipart/form-data’ content type is supported.

It sounds to me like the File-Type is supported.

[richardpringle]

@devInterests, the idea is that type "File" will eventually be supported.

Does your fileUpload method work at all? If not, I suggest either using loopback-component-storage, or go take a look at the code so you can implement your own.

The storage-service code is where you'll find the remote method and its metadata. The upload method actually call handler.upload which can be found in the storage-handler file.

I think it would be easiest to just add loopback-component-storage as a datasource service without exposing the container to the public REST API.

Keep the conversation going in here and we'll get your method working the way you want it to!

[devInterests]

@richardpringle thanks. My file upload works just fine, when I am using object as a Argument-Type. The problem here is that the Swagger-UI treats it as a object.

When I am using File as a Argument-Type, Swagger-UI treats it as a file upload. It is showing Browser-Button to select a File, and a Upload-Button. But then loopback get the error.

I would like to have the right definition with the File-Type, because then Swagger showing the Rest-Interface correctly (which is part of the rest documentation) and also I can test with Swagger directly.

[richardpringle]

Interesting,

I am going to re-open this issue as a feature request then.

@devInterests, would you be interested in submitting a PR to add support of type File?

[richardpringle]

@devInterests, what version of strong-remoting do you have? I just came across this issue that should support type File: https://github.com/strongloop/loopback/issues/2063#issuecomment-189204577

Edit: Sorry, that's actually only supported for returns

[bajtos]

Closing as a duplicate of https://github.com/strongloop/loopback/issues/2554

[bajtos]

Ooops, this is not a duplicate of strongloop/loopback#2554, reopening.

@devInterests if I understand your comments correctly, then you would like strong-remoting to support {arg: 'file', type: 'file', http: { source: 'body' }, required: true}, is that correct?

[bajtos]

Closing as a duplicate of https://github.com/strongloop/loopback/issues/3266