XHR Upload

The @sme-uploader/xhr-upload plugin handles classic HTML multipart form uploads, as well as uploads using the HTTP PUT method.

const XHRUpload = require('@sme-uploader/xhr-upload')

uploader.use(XHRUpload, {
  endpoint: 'http://my-website.org/upload'
})

Try it live

Installation

This plugin is published as the @sme-uploader/xhr-upload package.

Install from NPM:

npm install @sme-uploader/xhr-upload

In the CDN package, it is available on the SmeUploader global object:

const XHRUpload = SmeUploader.XHRUpload

Options

The @sme-uploader/xhr-upload plugin has the following configurable options:

id: 'XHRUpload'

A unique identifier for this plugin. It defaults to 'XHRUpload'.

endpoint: ''

The destination URL for your uploads.

method: 'post'

Configures which HTTP method to use for the upload.

formData: true

Configures whether or not to use a multipart form upload, using FormData.
This works similarly to using a <form> element with an <input type="file"> for uploads.
When set to true, file metadata is also sent to the endpoint as separate form fields.
When set to false, only the file contents are sent.

fieldName: 'files[]'

When formData is set to true, this is used as the form field name for the file to be uploaded.

metaFields: null

Pass an array of field names to limit the metadata fields that will be sent to the endpoint as form fields.

• Set this to ['name'] to only send the name field.
• Set this to null (the default) to send all metadata fields.
• Set this to an empty array [] to not send any fields.

If the formData option is set to false, metaFields has no effect.

headers: {}

An object containing HTTP headers to use for the upload request.
Keys are header names, values are header values.

headers: {
  'authorization': `Bearer ${window.getCurrentUserToken()}`
}

bundle: false

Send all files in a single multipart request. When bundle is set to true, formData must also be set to true.

⚠️ Only use bundle: true with local uploads (drag-drop, browse, webcam), SME Uploader won’t be able to bundle remote files (from Google Drive or Instagram), and will throw an error in this case.

Note: When bundle is set to true, only global uploader metadata, the one set via meta options property, is sent to the endpoint. Individual per-file metadata is ignored.

All files will be appended to the provided fieldName field in the request. To upload files on different fields, use uploader.setFileState() to set the xhrUpload.fieldName property on the file:

uploader.setFileState(fileID, {
  xhrUpload: { fieldName: 'pic0' }
})
uploader.setFileState(otherFileID, {
  xhrUpload: { fieldName: 'pic1' }
})

validateStatus(statusCode, responseText, response)

This option is only used for local uploads at this time. Uploads from remote providers like Google Drive or Instagram do not support this and will always use the default.

Check if the response from the upload endpoint indicates that the upload was successful. By default, responses with a 2xx HTTP status code are considered successful.

Return value

Return true if the response indicates success. Then, getResponseData() will be called and the upload will be marked as successful.

Return false if the response indicates failure. Then, both getResponseData() and getResponseError() will be called and the upload will be marked as unsuccessful.

Parameters

The statusCode is the numeric HTTP status code returned by the endpoint.

The responseText is the XHR endpoint response as a string.

response is the XMLHttpRequest object.

getResponseData(responseText, response)

When an upload has completed, SME Uploader will extract response data from the upload endpoint. This response data will be available on the file’s .response property, and be emitted in the upload-success event:

uploader.getFile(fileID).response
// { status: HTTP status code,
//   body: extracted response data }

uploader.on('upload-success', (file, response) => {
  response.status // HTTP status code
  response.body   // extracted response data

  // do something with file and response
})

By default, SME Uploader assumes the endpoint will return JSON. So, if POST /upload responds with:

{
  "url": "https://public.url/to/file",
  "whatever": "beep boop"
}

That object will be the value of response.body. Not all endpoints respond with JSON. Providing a getResponseData function overrides this behavior. The response parameter is the XMLHttpRequest instance used to upload the file.

For example, an endpoint that responds with an XML document:

getResponseData (responseText, response) {
  return {
    url: responseText.match(/<Location>(.*?)<\/Location>/)[1]
  }
}

Parameters

The responseText is the XHR endpoint response as a string.

For uploads from the user’s device, response is the XMLHttpRequest object.

When uploading files from remote providers such as Dropbox or Instagram, Companion sends upload response data to the client. This is made available in the getResponseData() function as well. The response object from Companion contains some properties named after their XMLHttpRequest counterparts:

• response.responseText - the XHR endpoint response as a string;
• response.status - the HTTP status code;
• response.statusText - the HTTP status text;
• response.headers - an object mapping lowercase header names to their values.

getResponseError(responseText, response)

If the upload endpoint responds with a non-2xx status code, the upload is assumed to have failed. The endpoint might have responded with some information about the error, though.

Pass in a getResponseError function to extract error data from the XMLHttpRequest instance used for the upload.

For example, if the endpoint responds with a JSON object containing a { message } property, this would show that message to the user:

getResponseError (responseText, response) {
  return new Error(JSON.parse(responseText).message)
}

responseUrlFieldName: 'url'

The field name containing a publically accessible location of the uploaded file in the response data returned by getResponseData().

timeout: 30 * 1000

When no upload progress events have been received for this amount of milliseconds, assume the connection has an issue and abort the upload.
Note that unlike the XMLHttpRequest.timeout property, this is a timer between progress events: the total upload can take longer than this value.
Set to 0 to disable this check.

The default for the timeout is 30 seconds.

limit: 0

Limit the amount of uploads going on at the same time. Setting this to 0 means there is no limit on concurrent uploads.

responseType: ''

The response type expected from the server, determining how the xhr.response property should be filled. The xhr.response property can be accessed in a custom getResponseData() callback. This option sets the [XMLHttpRequest.responseType][XHR.responseType] property. Only '', 'text', 'arraybuffer', 'blob' and 'document' are widely supported by browsers, so it's recommended to use one of those. The default is the empty string, which is equivalent to 'text' for the xhr.response` property.

withCredentials: false

Indicates whether or not cross-site Access-Control requests should be made using credentials.

locale: {}

Localize text that is shown to the user.

The default English strings are:

strings: {
  // Shown in the Informer if an upload is being canceled because it stalled for too long.
  timedOut: 'Upload stalled for %{seconds} seconds, aborting.'
}

POST Parameters / Form Fields

When using XHRUpload with formData: true, file metadata is sent along with each upload request. You can set metadata for a file using uploader.setFileMeta(fileID, data), or for all files simultaneously using uploader.setMeta(data).

It may be useful to set metadata depending on some file properties, such as the size. You can use the file-added event and the uploader.setFileMeta(fileID, data) method to do this:

uploader.on('file-added', (file) => {
  uploader.setFileMeta(file.id, {
    size: file.size
  })
})

Now, a form field named size will be sent along to the endpoint once the upload starts.

By default, all metadata is sent, including SME Uploader’s default name and type metadata. If you do not want the name and type metadata properties to be sent to your upload endpoint, you can use the metaFields option to restrict the field names that should be sent.

uploader.use(XHRUpload, {
  // Only send our own `size` metadata field.
  metaFields: ['size']
})

Uploading to a PHP Server

The XHRUpload plugin works similarly to a <form> upload. You can use the $_FILES variable on the server to work with uploaded files. See the PHP documentation on Handling file uploads.

The default form field for file uploads is files[], which means you have to access the $_FILES array as described in Uploading multiple files:

<?php
// upload.php
$files = $_FILES['files'];
$file_path = $files['tmp_name'][0]; // temporary upload path of the first file
$file_name = $_POST['name']; // desired name of the file
move_uploaded_file($file_path, './img/' . basename($file_name)); // save the file in `img/`

Note how we are using $_POST['name'] instead of $my_file['name']. $my_file['name'] contains the original name of the file on the user’s device. $_POST['name'] contains the name metadata value for the uploaded file, which can be edited by the user using the Dashboard.

Set a custom fieldName to make working with the $_FILES array a bit less convoluted:

// app.js
uploader.use(XHRUpload, {
  endpoint: '/upload.php',
  fieldName: 'my_file'
})

<?php
// upload.php
$my_file = $_FILES['my_file'];
$file_path = $my_file['tmp_name']; // temporary upload path of the file
$file_name = $_POST['name']; // desired name of the file
move_uploaded_file($file_path, './img/' . basename($file_name)); // save the file at `img/FILE_NAME`