lib/dynamic_image/helper.rb
# frozen_string_literal: true
module DynamicImage
# = DynamicImage Helper
#
# Provides helper methods for rendering and linking to images.
module Helper
# Returns the path for a DynamicImage::Model record.
# Takes the same options as +dynamic_image_url+
def dynamic_image_path(record_or_array, options = {})
dynamic_image_url(record_or_array, { routing_type: :path }.merge(options))
end
# Returns an HTML image tag for the record. If no size is given, it will
# render at the original size.
#
# ==== Options
# * <tt>:alt</tt>: If no alt text is given, it will default to the
# filename of the uploaded image.
#
# See +dynamic_image_url+ for info on how to size and cropping. Options
# supported by +polymorphic_url+ will be passed to the router. Any other
# options will be added as HTML attributes.
#
# ==== Examples
#
# image = Image.find(params[:id])
# dynamic_image_tag(image)
# # => <img alt="My file" height="200" src="..." width="320" />
# dynamic_image_tag(image, size: "100x100", alt="Avatar")
# # => <img alt="Avatar" height="62" src="..." width="100" />
def dynamic_image_tag(record_or_array, options = {})
record = extract_dynamic_image_record(record_or_array)
options = { alt: filename_to_alt(record.filename) }.merge(options)
size = fit_size!(record_or_array, options)
url_options = options.extract!(*allowed_dynamic_image_url_options)
html_options = { size: }.merge(options)
image_tag(dynamic_image_path_with_size(record_or_array,
size,
url_options),
html_options)
end
# Returns the URL for a DynamicImage::Model record.
#
# ==== Options
#
# * <tt>:size</tt> - Desired image size, supplied as "{width}x{height}".
# The image will be scaled to fit. A partial size like "100x" or "x100"
# can be given, if you want a fixed width or height.
# * <tt>:crop</tt> - If true, the image will be cropped to the given size.
# * <tt>:upscale</tt> - By default, DynamicImage only scale images down,
# never up. Pass <tt>upscale: true</tt> to force upscaling.
#
# Any options supported by +polymorphic_url+ are also accepted.
#
# ==== Examples
#
# image = Image.find(params[:id])
# dynamic_image_url(image)
# # => "http://example.com/images/96...d1/300x187/1-2014062020...00.jpg"
# dynamic_image_url(image, size: '100x100')
# # => "http://example.com/images/72...c2/100x62/1-2014062020...00.jpg"
# dynamic_image_url(image, size: '100x100', crop: true)
# # => "http://example.com/images/a4...6b/100x100/1-2014062020...00.jpg"
def dynamic_image_url(record_or_array, options = {})
size = fit_size!(record_or_array, options)
dynamic_image_url_with_size(record_or_array, size, options)
end
# Returns a path to the original uploaded file for download,
# without any processing applied. Sizing options are not
# supported.
def download_dynamic_image_path(record_or_array, options = {})
dynamic_image_path(record_or_array, { action: :download }.merge(options))
end
# Returns a URL to the original uploaded file for download,
# without any processing applied. Sizing options are not
# supported.
def download_dynamic_image_url(record_or_array, options = {})
dynamic_image_url(record_or_array, { action: :download }.merge(options))
end
# Returns a path to the original uploaded file, without any processing
# applied. Sizing options are not supported.
def original_dynamic_image_path(record_or_array, options = {})
dynamic_image_path(record_or_array, { action: :original }.merge(options))
end
# Returns a URL to the original uploaded file, without any processing
# applied. Sizing options are not supported.
def original_dynamic_image_url(record_or_array, options = {})
dynamic_image_url(record_or_array, { action: :original }.merge(options))
end
# Same as +dynamic_image_path+, but points to an image with any
# pre-cropping disabled.
def uncropped_dynamic_image_path(record_or_array, options = {})
dynamic_image_path(record_or_array, { action: :uncropped }.merge(options))
end
# Same as +dynamic_image_tag+, but renders an image with any
# pre-cropping disabled.
def uncropped_dynamic_image_tag(record_or_array, options = {})
dynamic_image_tag(record_or_array, { action: :uncropped }.merge(options))
end
# Same as +dynamic_image_url+, but points to an image with any
# pre-cropping disabled.
def uncropped_dynamic_image_url(record_or_array, options = {})
dynamic_image_url(record_or_array, { action: :uncropped }.merge(options))
end
private
def allowed_dynamic_image_url_options
%i[format only_path protocol host subdomain domain
tld_length port anchor trailing_slash script_name
action routing_type ]
end
def default_format_for_image(record)
Mime::Type.lookup(record.safe_content_type).to_sym
end
def dynamic_image_digest(record, action, size = nil)
key = [action || "show", record.id, size].compact.join("-")
DynamicImage.digest_verifier.generate(key)
end
def dynamic_image_path_with_size(record_or_array, size = nil, options = {})
dynamic_image_url_with_size(record_or_array,
size,
{ routing_type: :path }.merge(options))
end
def dynamic_image_url_with_size(record_or_array, size = nil, options = {})
record = extract_dynamic_image_record(record_or_array)
options = {
routing_type: :url,
action: nil,
format: default_format_for_image(record),
size:
}.merge(options)
options[:digest] =
dynamic_image_digest(record, options[:action], options[:size])
polymorphic_url(record_or_array, options)
end
def extract_dynamic_image_record(record_or_array)
case record_or_array
when Array
record_or_array.last
else
record_or_array
end
end
def filename_to_alt(str)
File.basename(str, ".*")
.sub(/-[[:xdigit:]]{32,64}\z/, "")
.tr("-_", " ")
.capitalize
end
def fit_size!(record_or_array, options)
record = extract_dynamic_image_record(record_or_array)
action = options[:action].try(:to_s)
size_opts = options.extract!(:size, :crop, :upscale)
if size_opts[:size]
image_sizing(record, size_opts, (action == "uncropped"))
else
(action == "original" ? record.real_size : record.size).floor.to_s
end
end
def image_sizing(record, size_opts, uncropped)
ImageSizing
.new(record, uncropped:)
.fit(size_opts[:size], size_opts).floor.to_s
end
end
end