Attaching files

Contains API calls which manipulate files attached to form's fields.

When submitting form values of type file, photo or signature, you need to provide file ID. To obtain it, first you create a file entry, then upload a file using provided credentials. File must adhere to limitations specified in the form field. Note that each file consumes space and contributes to file storage limit associated with user's account.

API actions

API path: /task/form/file.

create

Creates a new file entry associated with form's field. By making this call you basically "request permission" to upload a file. In return, you are provided with upload credentials (URL, form fields, etc.). Note that in order to actually "include" file as form field's value, creating and uploading file is not enough. You must then submit a form with file ID as a value of corresponding form field.

If file created but not uploaded, it will be deleted after date/time specified in "expires" response field. If file uploaded but not included as form field's value, it will be deleted on next form submission.

required sub-user rights: task_update.

Parameters

name	description	type
task_id	ID of the task to which form attached.	int
field_id	ID of the form's field to which a new file should be attached.	string
size	Maximum size in bytes for the file which will be uploaded. This is needed to "reserve" the space for a file in user's disk space quota.	int
filename	Optional. If specified, uploaded file will have the specified name. If not, name will be taken from actual file upload form.	string
metadata	Optional. Metadata object (for images only).	JSON object

Examples

cURL

curl -X POST 'https://api.eu.navixy.com/v2/task/form/file' \
    -H 'Content-Type: application/json' \
    -d '{"hash": "22eac1c27af4be7b9d04da2ce1af111b", "task_id": 11231, "field_id": "file1", "size": 10}'

HTTP GET

Response

when using internal storage:

{
  "success": true,
  "value": {
    "file_id": 111,
    "url": "http://bla.org/bla",
    "expires": "2020-02-03 03:04:00",
    "file_field_name": "file",
    "fields": {
      "token": "a43f43ed4340b86c808ac"
    }
  }
}

when using the Amazon S3:

{
  "success": true,
  "value": {
    "file_id": 111,
    "url": "https://bla.s3.amazonaws.com/",
    "expires": "2020-02-03 03:04:00",
    "file_field_name": "file",
    "fields": {
      "policy": "<Base64-encoded policy string>",
      "key": "user/user1/${filename}",
      "success_action_status": "200",
      "x-amz-algorithm": "AWS4-HMAC-SHA256",
      "x-amz-credential": "AKIAIOSFODNN7EXAMPLE/20151229/us-east-1/s3/aws4_request",
      "x-amz-date": "20151229T000000Z",
      "x-amz-signature": "<signature-value>",
      "x-amz-server-side-encryption": "AES256",
      "content-type": "image/png"
    }
  }
}

• file_id - int. This value will be submitted as form's field value.

• url - string. A URL to which POST form-data with file contents should be executed.

• expires - date/time. After this date file record wil expire and upload requests will be rejected.

• file_field_name - string. Name for file field in POST upload request.

• fields - these fields should be passed as additional fields in POST multipart upload request, field with a file must be the last one.

How to upload file data

Here's an example of upload you must make after receiving such response (assuming you uploading image named actual_file_name.png):

Internal storage example:

POST /bla HTTP/1.1
Host: bla.org
Content-Length: 1325
Origin: http://bla.org
... other headers ...
Content-Type: multipart/form-data; boundary=WebAppBoundary

--WebAppBoundary
Content-Disposition: form-data; name="token"

a43f43ed4340b86c808ac
--WebAppBoundary
Content-Disposition: form-data; name="file"; filename="actual_file_name.png"
Content-Type: image/png

... contents of file goes here ...
--WebAppBoundary--

Amazon S3 example:

POST / HTTP/1.1
Host:  https://bla.s3.amazonaws.com
Content-Length: 1972
Origin: https://bla.s3.amazonaws.com/
... other headers ...
Content-Type: multipart/form-data; boundary=WebAppBoundary

--WebAppBoundary
Content-Disposition: form-data; name="policy"
Content-Type: text/plain

eyJleHBpcmF0aW9uIjogIjIwMjMtMDMtMjdUMjE6MTU6MzYuMDczWiIsImNvbmRpdGlvbnMiOiNbeyJidWNrZXQiOiAibmF2aXh5LWZpbGVzLXRlc3QtZXUifSxbInN0YXJ0cy13aXRoIiwgIiRrZXkiLCAiIl0seyJzdWNjZXNzX2FjdGlvbl9zdGF0dXMiOiAiMjAwIn0seyJ4LWFtei1hbGdvcml0aG0iOiAiQVdTNC1ITUFDLVNIQTI1NiJ9LHsieC1hbXotY3JlZGVudGlhbCI6ICJBS0lBSUJRNlNSQjY1RVZTU1JNQS8yMDIzMDMyNy9ldS1jZW50cmFsLTEvczMvYXdzNF9yZXF1ZXN0In0seyJ4LWFtei1kYXRlIjogIjIwMjMwMzI3VDIxMDAzNloifSx7IngtYW16LXNlcnZlci1zaWRlLWVuY3J5cHRpb24iOiAiQUVTMjU2In1dfQ==
--WebAppBoundary
Content-Disposition: form-data; name="key"
Content-Type: text/plain

nj9relv6m52qp01t0wv47wyk1ozd309g/${filename}
--WebAppBoundary
Content-Disposition: form-data; name="success_action_status"
Content-Type: text/plain

200
--WebAppBoundary
Content-Disposition: form-data; name="x-amz-algorithm"
Content-Type: text/plain

AWS4-HMAC-SHA256
--WebAppBoundary
Content-Disposition: form-data; name="x-amz-credential"
Content-Type: text/plain

AKIAIBQ6SRB65EVSSRMA/20230327/eu-central-1/s3/aws4_request
--WebAppBoundary
Content-Disposition: form-data; name="x-amz-date"
Content-Type: text/plain

20230327T210036Z
--WebAppBoundary
Content-Disposition: form-data; name="x-amz-signature"
Content-Type: text/plain

2df7efa0c0e0c5b97d0d9483acd77c9ec37360df921b019a4c4a93180a6136ad
--WebAppBoundary
Content-Disposition: form-data; name="x-amz-server-side-encryption"
Content-Type: text/plain

AES256
--WebAppBoundary
Content-Disposition: form-data; name="file"; filename="actual_file_name.png"
Content-Type: image/png

... contents of file goes here ...
--WebAppBoundary--

Errors

• 201 – Not found in the database - if there is no task with such an ID, or task doesn't have form, or form has no field with such a field_id.

• 231 – Entity type mismatch - if form field is not file-based, i.e. doesn't use file ID as its value.

• 255 – Invalid task state - if current task state is not "unassigned", "assigned" or "arrived", or if task's form not submitted at least once.

• 267 – Too many entities - if there are 6 or more unsubmitted files already associated with this form's field.

• 268 – File cannot be created due to quota violation.

• 271 - File size is larger than the maximum allowed (by default 16 MB).