fix: implement TD-05, replacement of XML parser

This commit is contained in:
2026-06-12 11:48:44 +02:00
parent eac6d543d2
commit e3a1010ae9
8 changed files with 670 additions and 300 deletions

View File

@@ -1,143 +1,362 @@
defmodule BDS.WxrParser do
@moduledoc false
require Record
defmodule ParserState do
@moduledoc false
Record.defrecord(:xmlElement, Record.extract(:xmlElement, from_lib: "xmerl/include/xmerl.hrl"))
Record.defrecord(
:xmlAttribute,
Record.extract(:xmlAttribute, from_lib: "xmerl/include/xmerl.hrl")
)
Record.defrecord(:xmlText, Record.extract(:xmlText, from_lib: "xmerl/include/xmerl.hrl"))
def parse_file(file_path) when is_binary(file_path) do
file_path
|> File.read!()
|> parse_xml()
defstruct stack: [],
channel_seen?: false,
site: %{title: "", link: "", description: "", language: ""},
categories: [],
tags: [],
items: [],
current_category: nil,
current_tag: nil,
current_item: nil,
current_taxonomy: nil,
text: ""
end
def parse_xml(xml_content) when is_binary(xml_content) do
{document, _rest} = :xmerl_scan.string(String.to_charlist(xml_content))
defmodule Handler do
@moduledoc false
case :xmerl_xpath.string(~c"/rss/channel", document) do
[channel] ->
%{
site: parse_site(channel),
posts: parse_post_like_items(channel),
pages: parse_items(channel, "page"),
media: parse_media(channel),
categories: parse_categories(channel),
tags: parse_tags(channel)
}
@behaviour Saxy.Handler
_other ->
raise RuntimeError, "Invalid WXR file: no <channel> element found"
alias BDS.WxrParser.ParserState
def handle_event(:start_document, _prolog, state), do: {:ok, state}
def handle_event(:end_document, _data, state), do: {:ok, state}
def handle_event(:characters, chars, state) do
{:ok, %{state | text: state.text <> chars}}
end
def handle_event(:start_element, {name, attributes}, state) do
parent = current_name(state)
state =
state
|> push_name(name)
|> reset_text()
|> maybe_start_channel(parent, name)
|> maybe_start_category(parent, name)
|> maybe_start_tag(parent, name)
|> maybe_start_item(parent, name)
|> maybe_start_item_taxonomy(parent, name, attributes)
{:ok, state}
end
def handle_event(:end_element, name, state) do
parent = parent_name(state)
text = String.trim(state.text)
state =
state
|> maybe_capture_site_field(parent, name, text)
|> maybe_capture_category_field(parent, name, text)
|> maybe_finish_category(parent, name)
|> maybe_capture_tag_field(parent, name, text)
|> maybe_finish_tag(parent, name)
|> maybe_capture_item_field(parent, name, text)
|> maybe_finish_item_taxonomy(parent, name, text)
|> maybe_finish_item(parent, name)
|> pop_name()
|> reset_text()
{:ok, state}
end
defp current_name(%ParserState{stack: [name | _rest]}), do: name
defp current_name(%ParserState{}), do: nil
defp parent_name(%ParserState{stack: [_current, parent | _rest]}), do: parent
defp parent_name(%ParserState{}), do: nil
defp push_name(state, name), do: %{state | stack: [name | state.stack]}
defp pop_name(%ParserState{stack: [_name | rest]} = state), do: %{state | stack: rest}
defp pop_name(state), do: state
defp reset_text(state), do: %{state | text: ""}
defp maybe_start_channel(state, "rss", "channel"), do: %{state | channel_seen?: true}
defp maybe_start_channel(state, _parent, _name), do: state
defp maybe_start_category(state, "channel", "wp:category") do
%{state | current_category: %{name: "", slug: "", parent: ""}}
end
defp maybe_start_category(state, _parent, _name), do: state
defp maybe_start_tag(state, "channel", "wp:tag") do
%{state | current_tag: %{name: "", slug: ""}}
end
defp maybe_start_tag(state, _parent, _name), do: state
defp maybe_start_item(state, "channel", "item") do
%{state | current_item: empty_item()}
end
defp maybe_start_item(state, _parent, _name), do: state
defp maybe_start_item_taxonomy(state, "item", "category", attributes) do
%{state | current_taxonomy: %{domain: attribute_value(attributes, "domain")}}
end
defp maybe_start_item_taxonomy(state, _parent, _name, _attributes), do: state
defp maybe_capture_site_field(
%ParserState{current_category: nil, current_tag: nil, current_item: nil} = state,
"channel",
name,
text
) do
case name do
"title" -> put_in(state.site.title, text)
"link" -> put_in(state.site.link, text)
"description" -> put_in(state.site.description, text)
"language" -> put_in(state.site.language, text)
_other -> state
end
end
defp maybe_capture_site_field(state, _parent, _name, _text), do: state
defp maybe_capture_category_field(%ParserState{current_category: nil} = state, _parent, _name, _text),
do: state
defp maybe_capture_category_field(%ParserState{} = state, "wp:category", name, text) do
key =
case name do
"wp:cat_name" -> :name
"wp:category_nicename" -> :slug
"wp:category_parent" -> :parent
_other -> nil
end
if key do
update_in(state.current_category, &Map.put(&1, key, text))
else
state
end
end
defp maybe_capture_category_field(state, _parent, _name, _text), do: state
defp maybe_finish_category(%ParserState{current_category: nil} = state, _parent, _name), do: state
defp maybe_finish_category(%ParserState{} = state, "channel", "wp:category") do
%{state | categories: [state.current_category | state.categories], current_category: nil}
end
defp maybe_finish_category(state, _parent, _name), do: state
defp maybe_capture_tag_field(%ParserState{current_tag: nil} = state, _parent, _name, _text),
do: state
defp maybe_capture_tag_field(%ParserState{} = state, "wp:tag", name, text) do
key =
case name do
"wp:tag_name" -> :name
"wp:tag_slug" -> :slug
_other -> nil
end
if key do
update_in(state.current_tag, &Map.put(&1, key, text))
else
state
end
end
defp maybe_capture_tag_field(state, _parent, _name, _text), do: state
defp maybe_finish_tag(%ParserState{current_tag: nil} = state, _parent, _name), do: state
defp maybe_finish_tag(%ParserState{} = state, "channel", "wp:tag") do
%{state | tags: [state.current_tag | state.tags], current_tag: nil}
end
defp maybe_finish_tag(state, _parent, _name), do: state
defp maybe_capture_item_field(%ParserState{current_item: nil} = state, _parent, _name, _text),
do: state
defp maybe_capture_item_field(%ParserState{} = state, "item", name, text) do
key =
case name do
"title" -> :title
"pubDate" -> :pub_date
"dc:creator" -> :creator
"content:encoded" -> :content
"excerpt:encoded" -> :excerpt
"wp:post_id" -> :post_id
"wp:post_date" -> :post_date
"wp:post_modified" -> :post_modified
"wp:post_name" -> :post_name
"wp:status" -> :status
"wp:post_type" -> :post_type
"wp:post_parent" -> :post_parent
"wp:attachment_url" -> :attachment_url
_other -> nil
end
if key do
update_in(state.current_item, &Map.put(&1, key, text))
else
state
end
end
defp maybe_capture_item_field(state, _parent, _name, _text), do: state
defp maybe_finish_item_taxonomy(
%ParserState{current_item: nil, current_taxonomy: nil} = state,
_parent,
_name,
_text
),
do: state
defp maybe_finish_item_taxonomy(%ParserState{current_taxonomy: nil} = state, _parent, _name, _text),
do: state
defp maybe_finish_item_taxonomy(%ParserState{} = state, "item", "category", text) do
domain = Map.get(state.current_taxonomy, :domain)
state =
cond do
text == "" -> state
domain == "category" -> update_in(state.current_item.categories, &(&1 ++ [text]))
domain == "post_tag" -> update_in(state.current_item.tags, &(&1 ++ [text]))
true -> state
end
%{state | current_taxonomy: nil}
end
defp maybe_finish_item_taxonomy(state, _parent, _name, _text), do: state
defp maybe_finish_item(%ParserState{current_item: nil} = state, _parent, _name), do: state
defp maybe_finish_item(%ParserState{} = state, "channel", "item") do
%{state | items: [state.current_item | state.items], current_item: nil}
end
defp maybe_finish_item(state, _parent, _name), do: state
defp empty_item do
%{
post_id: "",
title: "",
post_name: "",
content: "",
excerpt: "",
pub_date: "",
post_date: "",
post_modified: "",
creator: "",
status: "",
post_type: "",
post_parent: "",
attachment_url: "",
categories: [],
tags: []
}
end
defp attribute_value(attributes, name) do
Enum.find_value(attributes, fn
{^name, value} -> value
_other -> nil
end)
end
end
defp parse_site(channel) do
def parse_file(file_path) when is_binary(file_path) do
file_path
|> File.stream!(32_768, [])
|> parse_document(&Saxy.parse_stream(&1, Handler, %ParserState{}))
end
def parse_xml(xml_content) when is_binary(xml_content) do
xml_content
|> parse_document(&Saxy.parse_string(&1, Handler, %ParserState{}))
end
defp parse_document(input, parser) do
case parser.(input) do
{:ok, %ParserState{channel_seen?: true} = state} ->
build_result(state)
{:ok, %ParserState{channel_seen?: false}} ->
raise RuntimeError, "Invalid WXR file: no <channel> element found"
{:error, error} ->
raise RuntimeError, Exception.message(error)
end
end
defp build_result(%ParserState{} = state) do
items = Enum.reverse(state.items)
%{
title: child_text(channel, "title"),
link: child_text(channel, "link"),
description: child_text(channel, "description"),
language: child_text(channel, "language")
site: state.site,
posts:
items
|> Enum.filter(fn item -> item.post_type not in ["", "attachment", "page"] end)
|> Enum.map(&parse_post_item/1),
pages:
items
|> Enum.filter(&(&1.post_type == "page"))
|> Enum.map(&parse_post_item/1),
media:
items
|> Enum.filter(&(&1.post_type == "attachment"))
|> Enum.map(&parse_media_item/1),
categories: Enum.reverse(state.categories),
tags: Enum.reverse(state.tags)
}
end
defp parse_categories(channel) do
channel
|> direct_children()
|> Enum.filter(&(full_name(&1) == "wp:category"))
|> Enum.map(fn element ->
%{
name: child_text(element, "cat_name"),
slug: child_text(element, "category_nicename"),
parent: child_text(element, "category_parent")
}
end)
end
defp parse_tags(channel) do
channel
|> direct_children()
|> Enum.filter(&(full_name(&1) == "wp:tag"))
|> Enum.map(fn element ->
%{
name: child_text(element, "tag_name"),
slug: child_text(element, "tag_slug")
}
end)
end
defp parse_items(channel, expected_type) do
channel
|> direct_children_named("item")
|> Enum.filter(&(child_text(&1, "post_type") == expected_type))
|> Enum.map(&parse_post_item/1)
end
defp parse_post_like_items(channel) do
channel
|> direct_children_named("item")
|> Enum.filter(fn item ->
type = child_text(item, "post_type")
type not in ["", "attachment", "page"]
end)
|> Enum.map(&parse_post_item/1)
end
defp parse_media(channel) do
channel
|> direct_children_named("item")
|> Enum.filter(&(child_text(&1, "post_type") == "attachment"))
|> Enum.map(&parse_media_item/1)
end
defp parse_post_item(item) do
%{
wp_id: parse_integer(child_text(item, "post_id")),
title: child_text(item, "title"),
slug: child_text(item, "post_name"),
content: child_text_by_full_name(item, "content:encoded"),
excerpt: child_text_by_full_name(item, "excerpt:encoded"),
pub_date: blank_to_nil(child_text(item, "pubDate")),
post_date: blank_to_nil(child_text(item, "post_date")),
post_modified: blank_to_nil(child_text(item, "post_modified")),
creator: child_text_by_full_name(item, "dc:creator"),
status: child_text(item, "status"),
post_type: child_text(item, "post_type"),
categories: item_taxonomy(item, "category"),
tags: item_taxonomy(item, "post_tag")
wp_id: parse_integer(item.post_id),
title: item.title,
slug: item.post_name,
content: item.content,
excerpt: item.excerpt,
pub_date: blank_to_nil(item.pub_date),
post_date: blank_to_nil(item.post_date),
post_modified: blank_to_nil(item.post_modified),
creator: item.creator,
status: item.status,
post_type: item.post_type,
categories: Enum.reject(item.categories, &(&1 == "")),
tags: Enum.reject(item.tags, &(&1 == ""))
}
end
defp parse_media_item(item) do
attachment_url = child_text(item, "attachment_url")
attachment_url = item.attachment_url
filename = attachment_url |> Path.basename() |> blank_to_nil() || ""
%{
wp_id: parse_integer(child_text(item, "post_id")),
title: child_text(item, "title"),
wp_id: parse_integer(item.post_id),
title: item.title,
url: attachment_url,
filename: filename,
relative_path: relative_upload_path(attachment_url),
pub_date: blank_to_nil(child_text(item, "pubDate")),
parent_id: parse_integer(child_text(item, "post_parent")),
pub_date: blank_to_nil(item.pub_date),
parent_id: parse_integer(item.post_parent),
mime_type: MIME.from_path(filename),
description: child_text_by_full_name(item, "content:encoded")
description: item.content
}
end
defp item_taxonomy(item, domain) do
item
|> direct_children_named("category")
|> Enum.filter(&(xml_attr(&1, :domain) == domain))
|> Enum.map(&text_content/1)
|> Enum.reject(&(&1 == ""))
end
defp relative_upload_path(url) when is_binary(url) do
marker = "/wp-content/uploads/"
@@ -147,69 +366,6 @@ defmodule BDS.WxrParser do
end
end
defp direct_children(element) do
Enum.filter(xmlElement(element, :content), fn child ->
is_tuple(child) and tuple_size(child) > 0 and elem(child, 0) == :xmlElement
end)
end
defp direct_children_named(element, name) do
Enum.filter(direct_children(element), &(local_name(&1) == name))
end
defp child_text(element, name) do
element
|> direct_children_named(name)
|> List.first()
|> text_content()
end
defp child_text_by_full_name(element, name) do
element
|> direct_children()
|> Enum.find(&(full_name(&1) == name))
|> text_content()
end
defp text_content(nil), do: ""
defp text_content(element) do
element
|> xmlElement(:content)
|> Enum.map_join("", fn
child when is_tuple(child) and tuple_size(child) > 0 and elem(child, 0) == :xmlText ->
child
|> xmlText(:value)
|> to_string()
child when is_tuple(child) and tuple_size(child) > 0 and elem(child, 0) == :xmlElement ->
text_content(child)
_other ->
""
end)
|> String.trim()
end
defp xml_attr(element, name) do
element
|> xmlElement(:attributes)
|> Enum.find_value(fn attribute ->
if xmlAttribute(attribute, :name) == name do
attribute |> xmlAttribute(:value) |> to_string()
end
end)
end
defp full_name(element), do: element |> xmlElement(:name) |> to_string()
defp local_name(element) do
element
|> full_name()
|> String.split(":")
|> List.last()
end
defp parse_integer(value) do
case Integer.parse(to_string(value)) do
{parsed, _rest} -> parsed