Rewrite extract_item and extract_items functions
This commit completely rewrites the extract_item and extract_items
function. Before this commit these two function were an unreadable
mess. The extract_item function was a lengthy if-elsif chain
while the extract_items function contained an incomprehensible
mess of .try, else and ||.
With this commit both of these functions have been pulled into a
separate file with the internal logic being moved to a few classes.
This significantly reduces the size of these two methods, enhances
readability and makes adding new extraction/parse rules much simpler.
See diff for details.
--
This cherry-picked commit also removes the code for parsing featured
channels present on the original.
(cherry picked from commit a027fbf7af)
pull/2228/head
syeopite
4 years ago
parent
6d68fbc31d
commit
1323b94b7a
@ -0,0 +1,317 @@
|
|||||||
|
# This file contains helper methods to parse the Youtube API json data into
|
||||||
|
# neat little packages we can use
|
||||||
|
|
||||||
|
# Tuple of Parsers/Extractors so we can easily cycle through them.
|
||||||
|
private ITEM_CONTAINER_EXTRACTOR = {
|
||||||
|
YoutubeTabsExtractor.new,
|
||||||
|
SearchResultsExtractor.new,
|
||||||
|
ContinuationExtractor.new,
|
||||||
|
}
|
||||||
|
|
||||||
|
private ITEM_PARSERS = {
|
||||||
|
VideoParser.new,
|
||||||
|
ChannelParser.new,
|
||||||
|
GridPlaylistParser.new,
|
||||||
|
PlaylistParser.new,
|
||||||
|
}
|
||||||
|
|
||||||
|
private struct AuthorFallback
|
||||||
|
property name, id
|
||||||
|
|
||||||
|
def initialize(@name : String? = nil, @id : String? = nil)
|
||||||
|
end
|
||||||
|
end
|
||||||
|
|
||||||
|
# The following are the parsers for parsing raw item data into neatly packaged structs.
|
||||||
|
# They're accessed through the process() method which validates the given data as applicable
|
||||||
|
# to their specific struct and then use the internal parse() method to assemble the struct
|
||||||
|
# specific to their category.
|
||||||
|
private class ItemParser
|
||||||
|
# Base type for all item parsers.
|
||||||
|
def process(item : JSON::Any, author_fallback : AuthorFallback)
|
||||||
|
end
|
||||||
|
|
||||||
|
private def parse(item_contents : JSON::Any, author_fallback : AuthorFallback)
|
||||||
|
end
|
||||||
|
end
|
||||||
|
|
||||||
|
private class VideoParser < ItemParser
|
||||||
|
def process(item, author_fallback)
|
||||||
|
if item_contents = (item["videoRenderer"]? || item["gridVideoRenderer"]?)
|
||||||
|
return self.parse(item_contents, author_fallback)
|
||||||
|
end
|
||||||
|
end
|
||||||
|
|
||||||
|
private def parse(item_contents, author_fallback)
|
||||||
|
video_id = item_contents["videoId"].as_s
|
||||||
|
title = item_contents["title"].try { |t| t["simpleText"]?.try &.as_s || t["runs"]?.try &.as_a.map(&.["text"].as_s).join("") } || ""
|
||||||
|
|
||||||
|
author_info = item_contents["ownerText"]?.try &.["runs"]?.try &.as_a?.try &.[0]?
|
||||||
|
author = author_info.try &.["text"].as_s || author_fallback.name || ""
|
||||||
|
author_id = author_info.try &.["navigationEndpoint"]?.try &.["browseEndpoint"]["browseId"].as_s || author_fallback.id || ""
|
||||||
|
|
||||||
|
published = item_contents["publishedTimeText"]?.try &.["simpleText"]?.try { |t| decode_date(t.as_s) } || Time.local
|
||||||
|
view_count = item_contents["viewCountText"]?.try &.["simpleText"]?.try &.as_s.gsub(/\D+/, "").to_i64? || 0_i64
|
||||||
|
description_html = item_contents["descriptionSnippet"]?.try { |t| parse_content(t) } || ""
|
||||||
|
length_seconds = item_contents["lengthText"]?.try &.["simpleText"]?.try &.as_s.try { |t| decode_length_seconds(t) } ||
|
||||||
|
item_contents["thumbnailOverlays"]?.try &.as_a.find(&.["thumbnailOverlayTimeStatusRenderer"]?).try &.["thumbnailOverlayTimeStatusRenderer"]?
|
||||||
|
.try &.["text"]?.try &.["simpleText"]?.try &.as_s.try { |t| decode_length_seconds(t) } || 0
|
||||||
|
|
||||||
|
live_now = false
|
||||||
|
paid = false
|
||||||
|
premium = false
|
||||||
|
|
||||||
|
premiere_timestamp = item_contents["upcomingEventData"]?.try &.["startTime"]?.try { |t| Time.unix(t.as_s.to_i64) }
|
||||||
|
|
||||||
|
item_contents["badges"]?.try &.as_a.each do |badge|
|
||||||
|
b = badge["metadataBadgeRenderer"]
|
||||||
|
case b["label"].as_s
|
||||||
|
when "LIVE NOW"
|
||||||
|
live_now = true
|
||||||
|
when "New", "4K", "CC"
|
||||||
|
# TODO
|
||||||
|
when "Premium"
|
||||||
|
# TODO: Potentially available as item_contents["topStandaloneBadge"]["metadataBadgeRenderer"]
|
||||||
|
premium = true
|
||||||
|
else nil # Ignore
|
||||||
|
end
|
||||||
|
end
|
||||||
|
|
||||||
|
SearchVideo.new({
|
||||||
|
title: title,
|
||||||
|
id: video_id,
|
||||||
|
author: author,
|
||||||
|
ucid: author_id,
|
||||||
|
published: published,
|
||||||
|
views: view_count,
|
||||||
|
description_html: description_html,
|
||||||
|
length_seconds: length_seconds,
|
||||||
|
live_now: live_now,
|
||||||
|
premium: premium,
|
||||||
|
premiere_timestamp: premiere_timestamp,
|
||||||
|
})
|
||||||
|
end
|
||||||
|
end
|
||||||
|
|
||||||
|
private class ChannelParser < ItemParser
|
||||||
|
def process(item, author_fallback)
|
||||||
|
if item_contents = item["channelRenderer"]?
|
||||||
|
return self.parse(item_contents, author_fallback)
|
||||||
|
end
|
||||||
|
end
|
||||||
|
|
||||||
|
private def parse(item_contents, author_fallback)
|
||||||
|
author = item_contents["title"]["simpleText"]?.try &.as_s || author_fallback.name || ""
|
||||||
|
author_id = item_contents["channelId"]?.try &.as_s || author_fallback.id || ""
|
||||||
|
|
||||||
|
author_thumbnail = item_contents["thumbnail"]["thumbnails"]?.try &.as_a[0]?.try &.["url"]?.try &.as_s || ""
|
||||||
|
subscriber_count = item_contents["subscriberCountText"]?.try &.["simpleText"]?.try &.as_s.try { |s| short_text_to_number(s.split(" ")[0]) } || 0
|
||||||
|
|
||||||
|
auto_generated = false
|
||||||
|
auto_generated = true if !item_contents["videoCountText"]?
|
||||||
|
video_count = item_contents["videoCountText"]?.try &.["runs"].as_a[0]?.try &.["text"].as_s.gsub(/\D/, "").to_i || 0
|
||||||
|
description_html = item_contents["descriptionSnippet"]?.try { |t| parse_content(t) } || ""
|
||||||
|
|
||||||
|
SearchChannel.new({
|
||||||
|
author: author,
|
||||||
|
ucid: author_id,
|
||||||
|
author_thumbnail: author_thumbnail,
|
||||||
|
subscriber_count: subscriber_count,
|
||||||
|
video_count: video_count,
|
||||||
|
description_html: description_html,
|
||||||
|
auto_generated: auto_generated,
|
||||||
|
})
|
||||||
|
end
|
||||||
|
end
|
||||||
|
|
||||||
|
private class GridPlaylistParser < ItemParser
|
||||||
|
def process(item, author_fallback)
|
||||||
|
if item_contents = item["gridPlaylistRenderer"]?
|
||||||
|
return self.parse(item_contents, author_fallback)
|
||||||
|
end
|
||||||
|
end
|
||||||
|
|
||||||
|
private def parse(item_contents, author_fallback)
|
||||||
|
title = item_contents["title"]["runs"].as_a[0]?.try &.["text"].as_s || ""
|
||||||
|
plid = item_contents["playlistId"]?.try &.as_s || ""
|
||||||
|
|
||||||
|
video_count = item_contents["videoCountText"]["runs"].as_a[0]?.try &.["text"].as_s.gsub(/\D/, "").to_i || 0
|
||||||
|
playlist_thumbnail = item_contents["thumbnail"]["thumbnails"][0]?.try &.["url"]?.try &.as_s || ""
|
||||||
|
|
||||||
|
SearchPlaylist.new({
|
||||||
|
title: title,
|
||||||
|
id: plid,
|
||||||
|
author: author_fallback.name || "",
|
||||||
|
ucid: author_fallback.id || "",
|
||||||
|
video_count: video_count,
|
||||||
|
videos: [] of SearchPlaylistVideo,
|
||||||
|
thumbnail: playlist_thumbnail,
|
||||||
|
})
|
||||||
|
end
|
||||||
|
end
|
||||||
|
|
||||||
|
private class PlaylistParser < ItemParser
|
||||||
|
def process(item, author_fallback)
|
||||||
|
if item_contents = item["playlistRenderer"]?
|
||||||
|
return self.parse(item_contents, author_fallback)
|
||||||
|
end
|
||||||
|
end
|
||||||
|
|
||||||
|
def parse(item_contents, author_fallback)
|
||||||
|
title = item_contents["title"]["simpleText"]?.try &.as_s || ""
|
||||||
|
plid = item_contents["playlistId"]?.try &.as_s || ""
|
||||||
|
|
||||||
|
video_count = item_contents["videoCount"]?.try &.as_s.to_i || 0
|
||||||
|
playlist_thumbnail = item_contents["thumbnails"].as_a[0]?.try &.["thumbnails"]?.try &.as_a[0]?.try &.["url"].as_s || ""
|
||||||
|
|
||||||
|
author_info = item_contents["shortBylineText"]?.try &.["runs"]?.try &.as_a?.try &.[0]?
|
||||||
|
author = author_info.try &.["text"].as_s || author_fallback.name || ""
|
||||||
|
author_id = author_info.try &.["navigationEndpoint"]?.try &.["browseEndpoint"]["browseId"].as_s || author_fallback.id || ""
|
||||||
|
|
||||||
|
videos = item_contents["videos"]?.try &.as_a.map do |v|
|
||||||
|
v = v["childVideoRenderer"]
|
||||||
|
v_title = v["title"]["simpleText"]?.try &.as_s || ""
|
||||||
|
v_id = v["videoId"]?.try &.as_s || ""
|
||||||
|
v_length_seconds = v["lengthText"]?.try &.["simpleText"]?.try { |t| decode_length_seconds(t.as_s) } || 0
|
||||||
|
SearchPlaylistVideo.new({
|
||||||
|
title: v_title,
|
||||||
|
id: v_id,
|
||||||
|
length_seconds: v_length_seconds,
|
||||||
|
})
|
||||||
|
end || [] of SearchPlaylistVideo
|
||||||
|
|
||||||
|
# TODO: item_contents["publishedTimeText"]?
|
||||||
|
|
||||||
|
SearchPlaylist.new({
|
||||||
|
title: title,
|
||||||
|
id: plid,
|
||||||
|
author: author,
|
||||||
|
ucid: author_id,
|
||||||
|
video_count: video_count,
|
||||||
|
videos: videos,
|
||||||
|
thumbnail: playlist_thumbnail,
|
||||||
|
})
|
||||||
|
end
|
||||||
|
end
|
||||||
|
|
||||||
|
# The following are the extractors for extracting an array of items from
|
||||||
|
# the internal Youtube API's JSON response. The result is then packaged into
|
||||||
|
# a structure we can more easily use via the parsers above. Their internals are
|
||||||
|
# identical to the item parsers.
|
||||||
|
|
||||||
|
private class ItemsContainerExtractor
|
||||||
|
def process(item : Hash(String, JSON::Any))
|
||||||
|
end
|
||||||
|
|
||||||
|
private def extract(target : JSON::Any)
|
||||||
|
end
|
||||||
|
end
|
||||||
|
|
||||||
|
private class YoutubeTabsExtractor < ItemsContainerExtractor
|
||||||
|
def process(initial_data)
|
||||||
|
if target = initial_data["twoColumnBrowseResultsRenderer"]?
|
||||||
|
self.extract(target)
|
||||||
|
end
|
||||||
|
end
|
||||||
|
|
||||||
|
private def extract(target)
|
||||||
|
raw_items = [] of JSON::Any
|
||||||
|
selected_tab = extract_selected_tab(target["tabs"])
|
||||||
|
content = selected_tab["tabRenderer"]["content"]
|
||||||
|
|
||||||
|
content["sectionListRenderer"]["contents"].as_a.each do |renderer_container|
|
||||||
|
renderer_container = renderer_container["itemSectionRenderer"]
|
||||||
|
renderer_container_contents = renderer_container["contents"].as_a[0]
|
||||||
|
|
||||||
|
# Shelf renderer usually refer to a category and would need special handling once
|
||||||
|
# An extractor for categories are added. But for now it is just used to
|
||||||
|
# extract items for the trending page
|
||||||
|
if items_container = renderer_container_contents["shelfRenderer"]?
|
||||||
|
if items_container["content"]["expandedShelfContentsRenderer"]?
|
||||||
|
items_container = items_container["content"]["expandedShelfContentsRenderer"]
|
||||||
|
end
|
||||||
|
elsif items_container = renderer_container_contents["gridRenderer"]?
|
||||||
|
else
|
||||||
|
items_container = renderer_container_contents
|
||||||
|
end
|
||||||
|
|
||||||
|
items_container["items"].as_a.each do |item|
|
||||||
|
raw_items << item
|
||||||
|
end
|
||||||
|
end
|
||||||
|
|
||||||
|
return raw_items
|
||||||
|
end
|
||||||
|
end
|
||||||
|
|
||||||
|
private class SearchResultsExtractor < ItemsContainerExtractor
|
||||||
|
def process(initial_data)
|
||||||
|
if target = initial_data["twoColumnSearchResultsRenderer"]?
|
||||||
|
self.extract(target)
|
||||||
|
end
|
||||||
|
end
|
||||||
|
|
||||||
|
private def extract(target)
|
||||||
|
raw_items = [] of JSON::Any
|
||||||
|
content = target["primaryContents"]
|
||||||
|
renderer = content["sectionListRenderer"]["contents"].as_a[0]["itemSectionRenderer"]
|
||||||
|
raw_items = renderer["contents"].as_a
|
||||||
|
|
||||||
|
return raw_items
|
||||||
|
end
|
||||||
|
end
|
||||||
|
|
||||||
|
private class ContinuationExtractor < ItemsContainerExtractor
|
||||||
|
def process(initial_data)
|
||||||
|
if target = initial_data["continuationContents"]?
|
||||||
|
self.extract(target)
|
||||||
|
end
|
||||||
|
end
|
||||||
|
|
||||||
|
private def extract(target)
|
||||||
|
raw_items = [] of JSON::Any
|
||||||
|
if content = target["gridContinuation"]?
|
||||||
|
raw_items = content["items"].as_a
|
||||||
|
end
|
||||||
|
|
||||||
|
return raw_items
|
||||||
|
end
|
||||||
|
end
|
||||||
|
|
||||||
|
def extract_item(item : JSON::Any, author_fallback : String? = nil, author_id_fallback : String? = nil)
|
||||||
|
# Parses an item from Youtube's JSON response into a more usable structure.
|
||||||
|
# The end result can either be a SearchVideo, SearchPlaylist or SearchChannel.
|
||||||
|
author_fallback = AuthorFallback.new(author_fallback, author_id_fallback)
|
||||||
|
|
||||||
|
# Cycles through all of the item parsers and attempt to parse the raw YT JSON data.
|
||||||
|
# Each parser automatically validates the data given to see if the data is
|
||||||
|
# applicable to itself. If not nil is returned and the next parser is attemped.
|
||||||
|
ITEM_PARSERS.each do |parser|
|
||||||
|
result = parser.process(item, author_fallback)
|
||||||
|
if !result.nil?
|
||||||
|
return result
|
||||||
|
end
|
||||||
|
end
|
||||||
|
# TODO radioRenderer, showRenderer, shelfRenderer, horizontalCardListRenderer, searchPyvRenderer
|
||||||
|
end
|
||||||
|
|
||||||
|
def extract_items(initial_data : Hash(String, JSON::Any), author_fallback : String? = nil, author_id_fallback : String? = nil)
|
||||||
|
items = [] of SearchItem
|
||||||
|
initial_data = initial_data["contents"]?.try &.as_h || initial_data["response"]?.try &.as_h || initial_data
|
||||||
|
|
||||||
|
# This is identicial to the parser cyling of extract_item().
|
||||||
|
ITEM_CONTAINER_EXTRACTOR.each do |extractor|
|
||||||
|
results = extractor.process(initial_data)
|
||||||
|
if !results.nil?
|
||||||
|
results.each do |item|
|
||||||
|
parsed_result = extract_item(item, author_fallback, author_id_fallback)
|
||||||
|
|
||||||
|
if !parsed_result.nil?
|
||||||
|
items << parsed_result
|
||||||
|
end
|
||||||
|
end
|
||||||
|
end
|
||||||
|
end
|
||||||
|
|
||||||
|
return items
|
||||||
|
end
|
||||||
Loading…
Reference in New Issue