Module: Axlsx::MimeTypeUtils

Defined in:
lib/axlsx/util/mime_type_utils.rb

Overview

This module defines some utils related with mime type detection

Constant Summary collapse

EXTENSION_FALLBACKS =

Extension to MIME type mapping for Windows fallback

{
  '.jpg' => 'image/jpeg',
  '.jpeg' => 'image/jpeg',
  '.png' => 'image/png',
  '.gif' => 'image/gif'
}.freeze

Class Method Summary collapse

Class Method Details

.get_mime_type(v) ⇒ String

Detect a file mime type

Parameters:

  • v (String) —

    File path

Returns:

  • (String) —

    File mime type



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# File 'lib/axlsx/util/mime_type_utils.rb', line 18

def get_mime_type(v)
  mime_type = Marcel::MimeType.for(Pathname.new(v))

  # Windows fallback: Marcel sometimes returns application/octet-stream for valid image files
  if mime_type == 'application/octet-stream' && windows_platform?
    extension = File.extname(v).downcase
    # Verify it's actually an image by checking the file header
    if EXTENSION_FALLBACKS.key?(extension) && File.exist?(v) && valid_image_file?(v, extension)
      mime_type = EXTENSION_FALLBACKS[extension]
    end
  end

  mime_type
end

.get_mime_type_from_uri(v) ⇒ String

Detect a file mime type from URI

Parameters:

  • v (String) —

    URI

Returns:

  • (String) —

    File mime type



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# File 'lib/axlsx/util/mime_type_utils.rb', line 36

def get_mime_type_from_uri(v)
  uri = URI.parse(v)

  unless uri.is_a?(URI::HTTP) || uri.is_a?(URI::HTTPS)
    raise URI::InvalidURIError, "Only HTTP/HTTPS URIs are supported"
  end

  response = UriUtils.fetch_headers(uri)
  mime_type = response&.[]('content-type')&.split(';')&.first&.strip

  if mime_type.nil? || mime_type.empty?
    raise ArgumentError, "Unable to determine MIME type from response"
  end

  mime_type
end