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require "uri"
require "open_graph_reader/base"
require "open_graph_reader/builder"
require "open_graph_reader/configuration"
require "open_graph_reader/definitions"
require "open_graph_reader/fetcher"
require "open_graph_reader/object"
require "open_graph_reader/parser"
require "open_graph_reader/version"
# @todo 1.1 compatibility mode?
# This module provides the main entry to the library. Please see the
# {file:README.md} for usage examples.
module OpenGraphReader
# Fetch the OpenGraph object at the given URL. Raise if there are any issues.
#
# @param [URI,#to_s] url The URL of the OpenGraph object to retrieve.
# @return [Base] The base object from which you can obtain the root objects.
# @raise [NoOpenGraphDataError] {include:NoOpenGraphDataError}
# @raise [InvalidObjectError] {include:InvalidObjectError}
def self.fetch! url
case url
when URI
target = Fetcher.new(url)
raise NoOpenGraphDataError, "#{url} doesn't contain any HTML" unless target.html?
parse! target.body, target.url
else
fetch! URI.parse(url.to_s)
end
end
# Parse the OpenGraph object in the given HTML document. Raise if there are any issues.
#
# @param [#to_s, Nokogiri::XML::Node] html A HTML document that contains an OpenGraph object.
# @param [#to_s] origin The source from where the given document was fetched.
# @return [Base] The base object from which you can obtain the root objects.
# @raise [NoOpenGraphDataError] {include:NoOpenGraphDataError}
# @raise [InvalidObjectError] {include:InvalidObjectError}
def self.parse! html, origin=nil
self.current_origin = origin
parser = Parser.new html
raise NoOpenGraphDataError, "#{origin || html} does not contain any OpenGraph tags" unless parser.any_tags?
Builder.new(parser).base.tap {|base|
base.origin = origin.to_s if origin
self.current_origin = nil
}
end
# Convenience wrapper around {OpenGraphReader.fetch!} that swallows the esceptions
# and returns nil instead.
#
# @param [URI,#to_s] url The URL of the OpenGraph object to retrieve.
# @return [Base, nil] The base object from which you can obtain the root objects.
# @see OpenGraphReader.fetch!
def self.fetch url
fetch! url
rescue NoOpenGraphDataError, InvalidObjectError
end
# Convenience wrapper around {OpenGraphReader.parse!} that swallows the esceptions
# and returns nil instead.
#
# @param [#to_s] html A HTML document that contains an OpenGraph object.
# @param [#to_s] origin The source from where the given document was fetched.
# @return [Base, nil] The base object from which you can obtain the root objects.
# @see OpenGraphReader.parse!
def self.parse html, origin=nil
parse! html, origin
rescue NoOpenGraphDataError, InvalidObjectError
end
# Configure the library, see {Configuration} for the list of available
# options and their defaults. Changing configuration at runtime is not
# thread safe.
#
# @yieldparam [Configuration] the configuration object
# @see Configuration
def self.configure
yield config
end
# Get the current {Configuration} instance
#
# @api private
# @return [Configuration]
def self.config
Configuration.instance
end
# Thread local to retrieve the current origin if available.
# See {Base#origin} if you want to know the origin of a parsed object.
#
# @api private
# @return [String,nil]
def self.current_origin
Thread.current[:_open_graph_reader_current_origin]
end
def self.current_origin= value
Thread.current[:_open_graph_reader_current_origin] = value
end
# The target couldn't be fetched, didn't contain any HTML or
# any OpenGraph tags.
class NoOpenGraphDataError < StandardError
end
# The target did contain OpenGraph tags, but they're not valid.
class InvalidObjectError < StandardError
end
# The target defines a namespace we have no definition for
#
# @api private
class UnknownNamespaceError < StandardError
end
# The target does not define the requested property.
class UndefinedPropertyError < StandardError
end
end
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