Note:
Although the demo implementations contained in this repository include source files from remote servers, it is recommended to download all dependencies and upload them to your own server.
This excludes script files hosted on Google's Content Delivery Network, which is a more reliable source than GitHub demo pages.

1. First read the Security guidelines.

2. After making sure that either .htaccess support is enabled or the sample Apache config has been installed, continue with the next step.

3. Download the plugin archive, extract it and upload the extracted folder (you may rename it) to your server.

4. Visit the uploaded directory - you should see the same file upload interface as the demo, allowing you to upload files to your website.

5. If uploading files doesn't work, make sure that the server/php/files directory permissions allow your server write access.

6. Upload a file named phpinfo.php containing <?php phpinfo(); and make sure that it does not get executed by your Webserver if you access its URL directly.

1. First read the Security guidelines.
2. Download the plugin archive, extract it and deploy the server/gae-python or server/gae-go folder (depending on which runtime environment you want to use) as your App Engine instance.
3. Upload the jQuery-File-Upload folder (without the server subfolder) to any server, after adjusting the url option in main.js to the url of your App Engine instance.

Visit the uploaded directory - you should see the same file upload interface as the demo, allowing you to upload files to your App Engine instance.

1. First read the Security guidelines.
2. Implement a file upload handler on your platform (Ruby, Python, Java, etc.) that handles normal form based file uploads and upload it to your server. See also the Server-side specific tutorials on the Documentation Homepage.
3. Download and extract the plugin archive.
4. Edit main.js and adjust the url option to the URL of your custom file upload handler. Alternatively you can remove the url option and edit index.html and adjust the action attribute of the HTML form element to the URL of your custom file upload handler. If your upload handler requires another parameter name for the file uploads than files[], you also have to adjust the file input name attribute or set the paramName option (see Options documentation).
5. Upload the jQuery-File-Upload folder to your website.
6. Extend your custom server-side upload handler to return a JSON response akin to the following output:

{"files": [
  {
    "name": "picture1.jpg",
    "size": 902604,
    "url": "http:\/\/example.org\/files\/picture1.jpg",
    "thumbnailUrl": "http:\/\/example.org\/files\/thumbnail\/picture1.jpg",
    "deleteUrl": "http:\/\/example.org\/files\/picture1.jpg",
    "deleteType": "DELETE"
  },
  {
    "name": "picture2.jpg",
    "size": 841946,
    "url": "http:\/\/example.org\/files\/picture2.jpg",
    "thumbnailUrl": "http:\/\/example.org\/files\/thumbnail\/picture2.jpg",
    "deleteUrl": "http:\/\/example.org\/files\/picture2.jpg",
    "deleteType": "DELETE"
  }
]}

To return errors to the UI, just add an error property to the individual file objects:

{"files": [
  {
    "name": "picture1.jpg",
    "size": 902604,
    "error": "Filetype not allowed"
  },
  {
    "name": "picture2.jpg",
    "size": 841946,
    "error": "Filetype not allowed"
  }
]}

When removing files using the delete button, the response should be like this:

{"files": [
  {
    "picture1.jpg": true
  },
  {
    "picture2.jpg": true
  }
]}

Note that the response should always be a JSON object containing a files array even if only one file is uploaded.

Visit the uploaded directory - you should see the same file upload interface as in the demo, allowing you to upload files to your website.

The file upload plugin makes use of an Iframe Transport module for browsers like Microsoft Internet Explorer and Opera, which do not yet support XMLHTTPRequest file uploads.
Iframe based uploads require a Content-type of text/plain or text/html for the JSON response - they will show an undesired download dialog if the iframe response is set to application/json.

You can make use of the Accept header to offer different content types for the file upload response. Here is the (PHP) example code snippet for the Accept content-type variation:

<?php
header('Vary: Accept');
if (isset($_SERVER['HTTP_ACCEPT']) &&
    (strpos($_SERVER['HTTP_ACCEPT'], 'application/json') !== false)) {
    header('Content-type: application/json');
} else {
    header('Content-type: text/plain');
}
?>

Here is a Ruby on Rails example to serve the proper Content-Type:

def update_attachment
  name  = params[:attachment_name]
  style = params[:attachment_style]
  image = params[:user][name]

  raise "No attachment #{name} for User!" unless User.attachment_definitions[name.to_sym]

  current_user.update("#{name}" => image)
  render(json: current_user.to_fileupload(name, style), content_type: request.format)
end

Thanks to the content_type option of render, the correct header is set for both IE and true browsers.

For the record, here is the to_fileupload method:

def to_fileupload(attachment_name, attachment_style)
  {
    files: [
      {
        id:   read_attribute(:id),
        name: read_attribute("#{attachment_name}_file_name"),
        type: read_attribute("#{attachment_name}_content_type"),
        size: read_attribute("#{attachment_name}_file_size"),
        url:  send(attachment_name).url(attachment_style)
      }
    ]
  }
end

If you want to build your own interface, please refer to the Basic plugin guide (minimal setup guide).