git.squeep.com Git - akkoma/blob - lib/pleroma/earmark_renderer.ex

   1 # Pleroma: A lightweight social networking server
   2 # Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
   3 # SPDX-License-Identifier: AGPL-3.0-only
   4 #
   5 # This file is derived from Earmark, under the following copyright:
   6 # Copyright © 2014 Dave Thomas, The Pragmatic Programmers
   7 # SPDX-License-Identifier: Apache-2.0
   8 # Upstream: https://github.com/pragdave/earmark/blob/master/lib/earmark/html_renderer.ex
   9 defmodule Pleroma.EarmarkRenderer do
  10   @moduledoc false
  11
  12   alias Earmark.Block
  13   alias Earmark.Context
  14   alias Earmark.HtmlRenderer
  15   alias Earmark.Options
  16
  17   import Earmark.Inline, only: [convert: 3]
  18   import Earmark.Helpers.HtmlHelpers
  19   import Earmark.Message, only: [add_messages_from: 2, get_messages: 1, set_messages: 2]
  20   import Earmark.Context, only: [append: 2, set_value: 2]
  21   import Earmark.Options, only: [get_mapper: 1]
  22
  23   @doc false
  24   def render(blocks, %Context{options: %Options{}} = context) do
  25     messages = get_messages(context)
  26
  27     {contexts, html} =
  28       get_mapper(context.options).(
  29         blocks,
  30         &render_block(&1, put_in(context.options.messages, []))
  31       )
  32       |> Enum.unzip()
  33
  34     all_messages =
  35       contexts
  36       |> Enum.reduce(messages, fn ctx, messages1 -> messages1 ++ get_messages(ctx) end)
  37
  38     {put_in(context.options.messages, all_messages), html |> IO.iodata_to_binary()}
  39   end
  40
  41   #############
  42   # Paragraph #
  43   #############
  44   defp render_block(%Block.Para{lnb: lnb, lines: lines, attrs: attrs}, context) do
  45     lines = convert(lines, lnb, context)
  46     add_attrs(lines, "<p>#{lines.value}</p>", attrs, [], lnb)
  47   end
  48
  49   ########
  50   # Html #
  51   ########
  52   defp render_block(%Block.Html{html: html}, context) do
  53     {context, html}
  54   end
  55
  56   defp render_block(%Block.HtmlComment{lines: lines}, context) do
  57     {context, lines}
  58   end
  59
  60   defp render_block(%Block.HtmlOneline{html: html}, context) do
  61     {context, html}
  62   end
  63
  64   #########
  65   # Ruler #
  66   #########
  67   defp render_block(%Block.Ruler{lnb: lnb, attrs: attrs}, context) do
  68     add_attrs(context, "<hr />", attrs, [], lnb)
  69   end
  70
  71   ###########
  72   # Heading #
  73   ###########
  74   defp render_block(
  75          %Block.Heading{lnb: lnb, level: level, content: content, attrs: attrs},
  76          context
  77        ) do
  78     converted = convert(content, lnb, context)
  79     html = "<h#{level}>#{converted.value}</h#{level}>"
  80     add_attrs(converted, html, attrs, [], lnb)
  81   end
  82
  83   ##############
  84   # Blockquote #
  85   ##############
  86
  87   defp render_block(%Block.BlockQuote{lnb: lnb, blocks: blocks, attrs: attrs}, context) do
  88     {context1, body} = render(blocks, context)
  89     html = "<blockquote>#{body}</blockquote>"
  90     add_attrs(context1, html, attrs, [], lnb)
  91   end
  92
  93   #########
  94   # Table #
  95   #########
  96
  97   defp render_block(
  98          %Block.Table{lnb: lnb, header: header, rows: rows, alignments: aligns, attrs: attrs},
  99          context
 100        ) do
 101     {context1, html} = add_attrs(context, "<table>", attrs, [], lnb)
 102     context2 = set_value(context1, html)
 103
 104     context3 =
 105       if header do
 106         append(add_trs(append(context2, "<thead>"), [header], "th", aligns, lnb), "</thead>")
 107       else
 108         # Maybe an error, needed append(context, html)
 109         context2
 110       end
 111
 112     context4 = append(add_trs(append(context3, "<tbody>"), rows, "td", aligns, lnb), "</tbody>")
 113
 114     {context4, [context4.value, "</table>"]}
 115   end
 116
 117   ########
 118   # Code #
 119   ########
 120
 121   defp render_block(
 122          %Block.Code{lnb: lnb, language: language, attrs: attrs} = block,
 123          %Context{options: options} = context
 124        ) do
 125     class =
 126       if language, do: ~s{ class="#{code_classes(language, options.code_class_prefix)}"}, else: ""
 127
 128     tag = ~s[<pre><code#{class}>]
 129     lines = options.render_code.(block)
 130     html = ~s[#{tag}#{lines}</code></pre>]
 131     add_attrs(context, html, attrs, [], lnb)
 132   end
 133
 134   #########
 135   # Lists #
 136   #########
 137
 138   defp render_block(
 139          %Block.List{lnb: lnb, type: type, blocks: items, attrs: attrs, start: start},
 140          context
 141        ) do
 142     {context1, content} = render(items, context)
 143     html = "<#{type}#{start}>#{content}</#{type}>"
 144     add_attrs(context1, html, attrs, [], lnb)
 145   end
 146
 147   # format a single paragraph list item, and remove the para tags
 148   defp render_block(
 149          %Block.ListItem{lnb: lnb, blocks: blocks, spaced: false, attrs: attrs},
 150          context
 151        )
 152        when length(blocks) == 1 do
 153     {context1, content} = render(blocks, context)
 154     content = Regex.replace(~r{</?p>}, content, "")
 155     html = "<li>#{content}</li>"
 156     add_attrs(context1, html, attrs, [], lnb)
 157   end
 158
 159   # format a spaced list item
 160   defp render_block(%Block.ListItem{lnb: lnb, blocks: blocks, attrs: attrs}, context) do
 161     {context1, content} = render(blocks, context)
 162     html = "<li>#{content}</li>"
 163     add_attrs(context1, html, attrs, [], lnb)
 164   end
 165
 166   ##################
 167   # Footnote Block #
 168   ##################
 169
 170   defp render_block(%Block.FnList{blocks: footnotes}, context) do
 171     items =
 172       Enum.map(footnotes, fn note ->
 173         blocks = append_footnote_link(note)
 174         %Block.ListItem{attrs: "#fn:#{note.number}", type: :ol, blocks: blocks}
 175       end)
 176
 177     {context1, html} = render_block(%Block.List{type: :ol, blocks: items}, context)
 178     {context1, Enum.join([~s[<div class="footnotes">], "<hr />", html, "</div>"])}
 179   end
 180
 181   #######################################
 182   # Isolated IALs are rendered as paras #
 183   #######################################
 184
 185   defp render_block(%Block.Ial{verbatim: verbatim}, context) do
 186     {context, "<p>{:#{verbatim}}</p>"}
 187   end
 188
 189   ####################
 190   # IDDef is ignored #
 191   ####################
 192
 193   defp render_block(%Block.IdDef{}, context), do: {context, ""}
 194
 195   #####################################
 196   # And here are the inline renderers #
 197   #####################################
 198
 199   defdelegate br, to: HtmlRenderer
 200   defdelegate codespan(text), to: HtmlRenderer
 201   defdelegate em(text), to: HtmlRenderer
 202   defdelegate strong(text), to: HtmlRenderer
 203   defdelegate strikethrough(text), to: HtmlRenderer
 204
 205   defdelegate link(url, text), to: HtmlRenderer
 206   defdelegate link(url, text, title), to: HtmlRenderer
 207
 208   defdelegate image(path, alt, title), to: HtmlRenderer
 209
 210   defdelegate footnote_link(ref, backref, number), to: HtmlRenderer
 211
 212   # Table rows
 213   defp add_trs(context, rows, tag, aligns, lnb) do
 214     numbered_rows =
 215       rows
 216       |> Enum.zip(Stream.iterate(lnb, &(&1 + 1)))
 217
 218     numbered_rows
 219     |> Enum.reduce(context, fn {row, lnb}, ctx ->
 220       append(add_tds(append(ctx, "<tr>"), row, tag, aligns, lnb), "</tr>")
 221     end)
 222   end
 223
 224   defp add_tds(context, row, tag, aligns, lnb) do
 225     Enum.reduce(1..length(row), context, add_td_fn(row, tag, aligns, lnb))
 226   end
 227
 228   defp add_td_fn(row, tag, aligns, lnb) do
 229     fn n, ctx ->
 230       style =
 231         case Enum.at(aligns, n - 1, :default) do
 232           :default -> ""
 233           align -> " style=\"text-align: #{align}\""
 234         end
 235
 236       col = Enum.at(row, n - 1)
 237       converted = convert(col, lnb, set_messages(ctx, []))
 238       append(add_messages_from(ctx, converted), "<#{tag}#{style}>#{converted.value}</#{tag}>")
 239     end
 240   end
 241
 242   ###############################
 243   # Append Footnote Return Link #
 244   ###############################
 245
 246   defdelegate append_footnote_link(note), to: HtmlRenderer
 247   defdelegate append_footnote_link(note, fnlink), to: HtmlRenderer
 248
 249   defdelegate render_code(lines), to: HtmlRenderer
 250
 251   defp code_classes(language, prefix) do
 252     ["" | String.split(prefix || "")]
 253     |> Enum.map(fn pfx -> "#{pfx}#{language}" end)
 254     |> Enum.join(" ")
 255   end
 256 end