Class: Url

Inherits:
Object
  • Object
show all
Defined in:
lib/imagekit/url.rb

Instance Method Summary collapse

Constructor Details

#initialize(request_obj) ⇒ Url

Returns a new instance of Url.



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# File 'lib/imagekit/url.rb', line 14

def initialize(request_obj)
  @req_obj = request_obj
end

Instance Method Details

#build_url(options) ⇒ Object 



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# File 'lib/imagekit/url.rb', line 26

def build_url(options)
  # build url from all options

  path = options.fetch(:path, "")
  src = options.fetch(:src, "")
  url_endpoint = options.fetch(:url_endpoint, "")
  transformation_position = options[:transformation_position]

  unless Default::VALID_TRANSFORMATION_POSITION.include? transformation_position
    raise ArgumentError, INVALID_TRANSFORMATION_POS
  end

  src_param_used_for_url = false
  if (src != "") || (transformation_position == Default::QUERY_TRANSFORMATION_POSITION)
    src_param_used_for_url = true
  end

  if path == "" && src == ""
    return ""
  end

  result_url_hash = {'host': "", 'path': "", 'query': ""}
  existing_query=nil
  if path != ""
    parsed_url = Addressable::URI.parse(path)
    existing_query=parsed_url.query
    parsed_host = Addressable::URI.parse(url_endpoint)
    result_url_hash[:scheme] = parsed_host.scheme

    # making sure single '/' at end
    result_url_hash[:host] = parsed_host.host.to_s.chomp("/") + parsed_host.path.chomp("/") + "/"
    result_url_hash[:path] = trim_slash(parsed_url.path)
  else
    parsed_url = Addressable::URI.parse(src)
    existing_query=parsed_url.query
    host = parsed_url.host
    result_url_hash[:userinfo] = parsed_url.userinfo if parsed_url.userinfo
    result_url_hash[:host] = host
    result_url_hash[:scheme] = parsed_url.scheme
    result_url_hash[:path] = parsed_url.path
    src_param_used_for_url = true
  end
  query_params = {}
  if existing_query!=nil
    existing_query.split("&").each do |part|
      parts=part.split("=")
      if parts.length==2
        query_params[parts[0]]=parts[1]
      end
    end
  end
  options.fetch(:query_parameters, {}).each do |key, value|
    query_params[key]=value
  end
  transformation_str = transformation_to_str(options[:transformation]).chomp("/")

  unless transformation_str.nil? || transformation_str.strip.empty?
    if (transformation_position == Default::QUERY_TRANSFORMATION_POSITION) || src_param_used_for_url == true
      result_url_hash[:query] = "#{Default::TRANSFORMATION_PARAMETER}=#{transformation_str}"
      query_params[:tr]=transformation_str
    else
      result_url_hash[:path] = "#{Default::TRANSFORMATION_PARAMETER}:#{transformation_str}/#{result_url_hash[:path]}"
    end

  end

  result_url_hash[:host] = result_url_hash[:host].to_s.reverse.chomp("/").reverse
  result_url_hash[:path] = result_url_hash[:path].chomp("/")
  result_url_hash[:scheme] ||= "https"

  query_param_arr = []
  query_param_arr.push("ik-sdk-version=ruby-"+Imagekit::Sdk::VERSION)
  query_params.each do |key, value|
    if value.to_s == ""
      query_param_arr.push(key.to_s)
    else
      query_param_arr.push(key.to_s + "=" + value.to_s)
    end
  end

  query_param_str = query_param_arr.join("&")
  result_url_hash[:query] = query_param_str

  # Signature String and Timestamp
  # We can do this only for URLs that are created using urlEndpoint and path parameter
  # because we need to know the endpoint to be able to remove it from the URL to create a signature
  # for the remaining. With the src parameter, we would not know the "pattern" in the URL
  if options[:signed] && !(options[:src])
    intermediate_url = result_url_hash.fetch(:scheme, "") + "://" + result_url_hash.fetch(:host, "") + result_url_hash.fetch(:path, "")
    if result_url_hash[:query]!=nil && result_url_hash[:query]!=""
      intermediate_url += result_url_hash.fetch(:query, "")
    end
  end

  url=hash_to_url(result_url_hash)
  if options[:signed]
    private_key = options[:private_key]
    expire_seconds = options[:expire_seconds]
    expire_timestamp = get_signature_timestamp(expire_seconds)
    url_signature = get_signature(private_key, url, url_endpoint, expire_timestamp)
    query_param_arr.push(Default::SIGNATURE_PARAMETER + "=" + url_signature)

    if expire_timestamp && (expire_timestamp != Default::TIMESTAMP)
      query_param_arr.push(Default::TIMESTAMP_PARAMETER + "=" + expire_timestamp.to_s)
    end
  
    query_param_str = query_param_arr.join("&")
    result_url_hash[:query] = query_param_str
    
    url=hash_to_url(result_url_hash)
  end
  url
end

#extend_url_options(options) ⇒ Object 



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# File 'lib/imagekit/url.rb', line 198

def extend_url_options(options)
  attr_dict = {"public_key": @req_obj.public_key,
               "private_key": @req_obj.private_key,
               "url_endpoint": @req_obj.url_endpoint,
               "transformation_position": @req_obj.transformation_position, }
  # extending  url options
  attr_dict.merge(options)
end

#generate_url(options) ⇒ Object 



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# File 'lib/imagekit/url.rb', line 18

def generate_url(options)
  if options.key? :src
    options[:transformation_position] = Default::TRANSFORMATION_POSITION
  end
  extended_options = extend_url_options(options)
  build_url(extended_options)
end

#get_signature(private_key, url, url_endpoint, expiry_timestamp) ⇒ Object 



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# File 'lib/imagekit/url.rb', line 184

def get_signature(private_key, url, url_endpoint, expiry_timestamp)
  # creates signature(hashed hex key) and returns from
  # private_key, url, url_endpoint and expiry_timestamp
  if expiry_timestamp==0
    expiry_timestamp=Default::DEFAULT_TIMESTAMP
  end
  if url_endpoint[url_endpoint.length-1]!="/"
    url_endpoint+="/"
  end
  replaced_url=url.gsub(url_endpoint, "")
  replaced_url =  replaced_url + expiry_timestamp.to_s
  OpenSSL::HMAC.hexdigest("SHA1", private_key, replaced_url)
end

#get_signature_timestamp(seconds) ⇒ Object 



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# File 'lib/imagekit/url.rb', line 172

def get_signature_timestamp(seconds)
  # this function returns either default time stamp
  # or current unix time and expiry seconds to get
  # signature time stamp

  if seconds.to_i == 0
    Default::DEFAULT_TIMESTAMP
  else
    DateTime.now.strftime("%s").to_i + seconds.to_i
  end
end

#hash_to_url(url_hash) ⇒ Object 



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# File 'lib/imagekit/url.rb', line 207

def hash_to_url(url_hash)
  generated_url = url_hash.fetch(:scheme, "") + "://" + url_hash.fetch(:host, "") + url_hash.fetch(:path, "")
  if url_hash[:query] != ""
    generated_url = generated_url + "?" + url_hash.fetch(:query, "")
    return generated_url
  end
  generated_url
end

#transformation_to_str(transformation) ⇒ Object 



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# File 'lib/imagekit/url.rb', line 140

def transformation_to_str(transformation)
  # creates transformation_position string for url
  # from transformation dictionary

  unless transformation.is_a?(Array)
    return ""
  end

  parsed_transforms = []
  (0..(transformation.length - 1)).each do |i|
    parsed_transform_step = []

    transformation[i].keys.each do |key|
      transform_key = SUPPORTED_TRANS.fetch(key, nil)
      transform_key ||= key

      if transform_key == "oi" || transform_key == "di"
        transformation[i][key][0] = "" if transformation[i][key][0] == "/"
        transformation[i][key] = transformation[i][key].gsub("/", "@@")
      end

      if transformation[i][key] == "-"
        parsed_transform_step.push(transform_key)
      else
        parsed_transform_step.push("#{transform_key}#{Default::TRANSFORM_KEY_VALUE_DELIMITER}#{transformation[i][key]}")
      end
    end
    parsed_transforms.push(parsed_transform_step.join(Default::TRANSFORM_DELIMITER))
  end
  parsed_transforms.join(Default::CHAIN_TRANSFORM_DELIMITER)
end

#trim_slash(str, both = true) ⇒ Object 



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# File 'lib/imagekit/url.rb', line 216

def trim_slash(str, both = true)
  if str == ""
    return ""
  end
  # remove slash from a string
  # if both is not provide trims both slash
  # example - '/abc/' returns 'abc'
  # if both=false it will only trim end slash
  # example - '/abc/' returns '/abc'
  # NOTE: IT'S RECOMMENDED TO USE inbuilt .chomp('string you want to remove')
  # FOR REMOVING ONLY TRAILING SLASh
  if both
    str[0].chomp("/") + str[1..-2] + str[-1].chomp("/")
  else
    str.chomp("/")
  end
end