Formidable Upload

Chainable file upload api for express using formidable.

Installation

$ npm install formidable-upload

Usage

var upload = require('formidable-upload');

// ..

upload()
    .accept('image/jpeg')
    .to(['public', 'images'])
    .resize({
        use: 'resize',
        settings: {
            width: 800,
            quality: 80
        }
    })
    .imguri()
    .exec(req.files.displayImage, function(err, file) {
        // further process file
    });

Processing Chains

After creating an Upload object by calling upload() the upload object exposes API methods

accept

Restricts files accepted by upload to specified mime types. Mime types can be specified as strings, array of strings, regex or array of regex. In case match fails an err object is passed to the exec callback field accept set to true.

Examples

Accept mp4, ogg and jpeg files in upload

  accept(['audio/mp4', 'audio/ogg', 'image/jpeg'])

Accept only mp4

  accept('audio/mp4')

Accept all image mime types

  accept([/image*/])

to

Moves files from temp express upload location to the target location. The to processor modifies file.path and file.name fields of the original express upload file to point to the moved upload file. to will use any given file extension from the original file.name. A target directory is expected as argument, in case an array of strings is passed this array will be joined via path.join.

Examples

Moves uploaded files to public/images

  to(['public', 'images'])

Moves uploaded files to public/images

  to('public/images')

resize

Allows uploaded files to be processed via Magickwand. See magickwand page for using magickwand. Magicwand supports resize and thumbnail methods. Please refer the magickwand page if you face any issue while installing the module.

Examples

Resize an uploaded image to width of 800 and quality of 80 maintaining the aspect ratio.

  resize({
      use: 'resize',
      settings: {
          width: 800,
          quality: 80
      }
  })

imguri

Convert the uploaded image to data uri, sets req.files.userfile.data with Base64 encoded data.

  imguri()

process

Generic handler to pass custom transformation code in the processing chain. Functions passed to process must have the signature

  fn(file, cb)

Where file is the processed upload file and cb is the callback.

exec

Executes a processing chain. Processing chains are reusable and may be executed multiple times. In case the file is not part of the upload or is empty an err is passed to the callback with a field noFile set to true.

Middleware

Instead of executing and managing upload file processing in your routes, express-upload can be used as middleware in express. Any processing errors (no file, file type not accepted,...) are stored in a err property of the file to upload.

Example

  // Build an upload instance but don't execute it right now
  var uploader = upload()
      .accept('image/jpeg')
      .to(['public', 'images'])
      .resize({
          use: 'resize',
          settings: {
              width: 800,
              quality: 80
          }
      })
      .imguri();


  // Define a middleware for handling image upload
  app.post('/upload', uploader.middleware('userfile'), routes.upload);

In case an error would occur when uploading the next middleware will be called with the error.

Example Code

Formidable Upload Example.