# Multipart::Post

Adds a streamy multipart form post capability to `Net::HTTP`. Also supports other
methods besides `POST`.

[![Development Status](https://github.com/socketry/multipart-post/workflows/Test/badge.svg)](https://github.com/socketry/multipart-post/actions?workflow=Test)

## Features/Problems

  - Appears to actually work. A good feature to have.
  - Encapsulates posting of file/binary parts and name/value parameter parts, similar to
    most browsers' file upload forms.
  - Provides an `UploadIO` helper class to prepare IO objects for inclusion in the params
    hash of the multipart post object.

## Installation

``` shell
bundle add multipart-post
```

## Usage

``` ruby
require 'net/http/post/multipart'

url = URI.parse('http://www.example.com/upload')
File.open("./image.jpg") do |jpg|
  req = Net::HTTP::Post::Multipart.new url.path,
    "file" => UploadIO.new(jpg, "image/jpeg", "image.jpg")
  res = Net::HTTP.start(url.host, url.port) do |http|
    http.request(req)
  end
end
```

To post multiple files or attachments, simply include multiple parameters with
`UploadIO` values:

``` ruby
require 'net/http/post/multipart'

url = URI.parse('http://www.example.com/upload')
req = Net::HTTP::Post::Multipart.new url.path,
  "file1" => UploadIO.new(File.new("./image.jpg"), "image/jpeg", "image.jpg"),
  "file2" => UploadIO.new(File.new("./image2.jpg"), "image/jpeg", "image2.jpg")
res = Net::HTTP.start(url.host, url.port) do |http|
  http.request(req)
end
```

To post files with other normal, non-file params such as input values, you need to pass hashes to the `Multipart.new` method.

In Rails 4 for example:

``` ruby
def model_params
  require_params = params.require(:model).permit(:param_one, :param_two, :param_three, :avatar)
  require_params[:avatar] = model_params[:avatar].present? ? UploadIO.new(model_params[:avatar].tempfile, model_params[:avatar].content_type, model_params[:avatar].original_filename) : nil
  require_params
end

require 'net/http/post/multipart'

url = URI.parse('http://www.example.com/upload')
Net::HTTP.start(url.host, url.port) do |http|
  req = Net::HTTP::Post::Multipart.new(url, model_params)
  key = "authorization_key"
  req.add_field("Authorization", key) #add to Headers
  http.use_ssl = (url.scheme == "https")
  http.request(req)
end
```

Or in plain ruby:

``` ruby
def params(file)
  params = { "description" => "A nice picture!" }
  params[:datei] = UploadIO.new(file, "image/jpeg", "image.jpg")
  params
end

url = URI.parse('http://www.example.com/upload')
File.open("./image.jpg") do |file|
  req = Net::HTTP::Post::Multipart.new(url.path, params(file))
  res = Net::HTTP.start(url.host, url.port) do |http|
    return http.request(req).body
  end
end
```

### Parts Headers

By default, all individual parts will include the header `Content-Disposition` as well as `Content-Length`, `Content-Transfer-Encoding` and `Content-Type` for the File Parts.

You may optionally configure the headers `Content-Type` and `Content-ID` for both ParamPart and FilePart by passing in a `parts` header.

For example:

``` ruby
url = URI.parse('http://www.example.com/upload')

params = {
  "file_metadata_01" => { "description" => "A nice picture!" },
  "file_content_01"  => UploadIO.new(file, "image/jpeg", "image.jpg")
}

headers = {
  'parts': {
    'file_metadata_01': {
      'Content-Type' => "application/json"
      }
    }
  }

req = Net::HTTP::Post::Multipart.new(uri, params, headers)
```

This would configure the `file_metadata_01` part to include `Content-Type`

    Content-Disposition: form-data; name="file_metadata_01"
    Content-Type: application/json
      {
        "description" => "A nice picture!" 
      }

#### Custom Parts Headers

*For FileParts only.*

You can include any number of custom parts headers in addition to `Content-Type` and `Content-ID`.

``` ruby
headers = {
  'parts': {
    'file_metadata_01': {
      'Content-Type' => "application/json",
      'My-Custom-Header' => "Yo Yo!"
    }
  }
}
```

### Debugging

You can debug requests and responses (e.g. status codes) for all requests by adding the following code:

``` ruby
http = Net::HTTP.new(uri.host, uri.port)
http.set_debug_output($stdout)
```

## Versioning

This library aims to adhere to [Semantic Versioning 2.0.0](http://semver.org/).
Violations of this scheme should be reported as bugs. Specifically,
if a minor or patch version is released that breaks backward
compatibility, a new version should be immediately released that
restores compatibility. Breaking changes to the public API will
only be introduced with new major versions.

As a result of this policy, you can (and should) specify a
dependency on this gem using the [Pessimistic Version Constraint](http://guides.rubygems.org/patterns/#pessimistic-version-constraint) with two digits of precision.

For example:

``` ruby
spec.add_dependency 'multipart-post', '~> 2.1'
```