66 lines
1.9 KiB
Ruby
66 lines
1.9 KiB
Ruby
|
# frozen_string_literal: true
|
||
|
|
||
|
module Banzai
|
||
|
module Filter
|
||
|
# HTML filter that inserts a node for each occurence of
|
||
|
# a given link format. To transform references to DB
|
||
|
# resources in place, prefer to inherit from AbstractReferenceFilter.
|
||
|
class InlineEmbedsFilter < HTML::Pipeline::Filter
|
||
|
# Find every relevant link, create a new node based on
|
||
|
# the link, and insert this node after any html content
|
||
|
# surrounding the link.
|
||
|
def call
|
||
|
doc.xpath(xpath_search).each do |node|
|
||
|
next unless element = element_to_embed(node)
|
||
|
|
||
|
# We want this to follow any surrounding content. For example,
|
||
|
# if a link is inline in a paragraph.
|
||
|
node.parent.children.last.add_next_sibling(element)
|
||
|
end
|
||
|
|
||
|
doc
|
||
|
end
|
||
|
|
||
|
# Implement in child class.
|
||
|
#
|
||
|
# Return a Nokogiri::XML::Element to embed in the
|
||
|
# markdown.
|
||
|
def create_element(params)
|
||
|
end
|
||
|
|
||
|
# Implement in child class unless overriding #embed_params
|
||
|
#
|
||
|
# Returns the regex pattern used to filter
|
||
|
# to only matching urls.
|
||
|
def link_pattern
|
||
|
end
|
||
|
|
||
|
# Returns the xpath query string used to select nodes
|
||
|
# from the html document on which the embed is based.
|
||
|
#
|
||
|
# Override to select nodes other than links.
|
||
|
def xpath_search
|
||
|
'descendant-or-self::a[@href]'
|
||
|
end
|
||
|
|
||
|
# Creates a new element based on the parameters
|
||
|
# obtained from the target link
|
||
|
def element_to_embed(node)
|
||
|
return unless params = embed_params(node)
|
||
|
|
||
|
create_element(params)
|
||
|
end
|
||
|
|
||
|
# Returns a hash of named parameters based on the
|
||
|
# provided regex with string keys.
|
||
|
#
|
||
|
# Override to select nodes other than links.
|
||
|
def embed_params(node)
|
||
|
url = node['href']
|
||
|
|
||
|
link_pattern.match(url) { |m| m.named_captures }
|
||
|
end
|
||
|
end
|
||
|
end
|
||
|
end
|