module Banzai # Class for rendering multiple objects (e.g. Note instances) in a single pass, # using +render_field+ to benefit from caching in the database. Rendering and # redaction are both performed. # # The unredacted HTML is generated according to the usual +render_field+ # policy, so specify the pipeline and any other context options on the model. # # The *redacted* (i.e., suitable for use) HTML is placed in an attribute # named "redacted_<foo>", where <foo> is the name of the cache field for the # chosen attribute. # # As an example, rendering the attribute `note` would place the unredacted # HTML into `note_html` and the redacted HTML into `redacted_note_html`. class ObjectRenderer attr_reader :project, :user # project - A Project to use for redacting Markdown. # user - The user viewing the Markdown/HTML documents, if any. # context - A Hash containing extra attributes to use during redaction def initialize(project, user = nil, redaction_context = {}) @project = project @user = user @redaction_context = redaction_context end # Renders and redacts an Array of objects. # # objects - The objects to render. # attribute - The attribute containing the raw Markdown to render. # # Returns the same input objects. def render(objects, attribute) documents = render_documents(objects, attribute) documents = post_process_documents(documents, objects, attribute) redacted = redact_documents(documents) objects.each_with_index do |object, index| redacted_data = redacted[index] object.__send__("redacted_#{attribute}_html=", redacted_data[:document].to_html.html_safe) object.user_visible_reference_count = redacted_data[:visible_reference_count] end end private def render_documents(objects, attribute) pipeline = HTML::Pipeline.new([]) objects.map do |object| pipeline.to_document(Banzai.render_field(object, attribute)) end end def post_process_documents(documents, objects, attribute) # Called here to populate cache, refer to IssuableExtractor docs IssuableExtractor.new(project, user).extract(documents) documents.zip(objects).map do |document, object| context = context_for(object, attribute) Banzai::Pipeline[:post_process].to_document(document, context) end end # Redacts the list of documents. # # Returns an Array containing the redacted documents. def redact_documents(documents) redactor = Redactor.new(project, user) redactor.redact(documents) end # Returns a Banzai context for the given object and attribute. def context_for(object, attribute) base_context.merge(object.banzai_render_context(attribute)) end def base_context @base_context ||= @redaction_context.merge( current_user: user, project: project, skip_redaction: true ) end end end