Class: Post

Inherits:
Object
  • Object
show all
Defined in:
lib/Post.rb

Defined Under Namespace

Classes: PostInfo

Constant Summary collapse

POST_VIEWER_EDGE_QUERY_PATH = 
File.expand_path('Queries/PostViewerEdgeContentQuery.graphql', __dir__).freeze
POST_PAGE_QUERY_PATH = 
File.expand_path('Queries/PostPageQuery.graphql', __dir__).freeze

Class Method Summary collapse

Class Method Details

.fetchPostParagraphs(postID) ⇒ Object 



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# File 'lib/Post.rb', line 28

def self.fetchPostParagraphs(postID)
  json = postGraphQL("PostViewerEdgeContentQuery", postViewerEdgeContentQueryString,
                     { "postId" => postID })
  json&.dig(0, "data", "post", "viewerEdge", "fullContent")
end

.getPostIDFromPostURLString(postURLString) ⇒ Object 



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# File 'lib/Post.rb', line 18

def self.getPostIDFromPostURLString(postURLString)
  uri = URI.parse(postURLString)
  uri.path.split('/').last.split('-').last
end

.getPostPathFromPostURLString(postURLString) ⇒ Object 



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# File 'lib/Post.rb', line 23

def self.getPostPathFromPostURLString(postURLString)
  uri = URI.parse(postURLString)
  uri.path.split('/').last
end

.parsePostInfo(postID, pathPolicy) ⇒ Object

Fetches post-level metadata (title, tags, creator, dates, preview image, collection) directly from Medium’s PostPageQuery GraphQL operation. Replaces the previous approach of scraping window.APOLLO_STATE out of the post HTML page, which Medium has been progressively dismantling.



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# File 'lib/Post.rb', line 38

def self.parsePostInfo(postID, pathPolicy)
  json = postGraphQL("PostPageQuery", postPageQueryString,
                     { "postId" => postID,
                       "postMeteringOptions" => { "referrer" => "https://medium.com/me/stories" },
                       "includeShouldFollowPost" => false })
  return nil if json.nil?

  result = json.dig(0, "data", "postResult")
  return nil if result.nil?

  postInfo = PostInfo.new
  postInfo.description = result.dig("previewContent", "subtitle")&.gsub(/[^[:print:]]/, '')
  postInfo.title = result["title"]&.gsub(/[^[:print:]]/, '')
  postInfo.tags = result["tags"]&.map { |tag| tag["normalizedTagSlug"] }
  postInfo.creator = result.dig("creator", "name")
  postInfo.collectionName = result.dig("collection", "name")

  firstPublishedAt = result["firstPublishedAt"]
  postInfo.firstPublishedAt = Time.at(0, firstPublishedAt, :millisecond) if firstPublishedAt

  latestPublishedAt = result["latestPublishedAt"]
  postInfo.latestPublishedAt = Time.at(0, latestPublishedAt, :millisecond) if latestPublishedAt

  previewImageFileName = result.dig("previewImage", "id")
  if previewImageFileName
    imagePathPolicy = PathPolicy.new(pathPolicy.getAbsolutePath(postID), pathPolicy.getRelativePath(postID))
    absolutePath = imagePathPolicy.getAbsolutePath(previewImageFileName)

    miro_host = ENV.fetch('MIRO_MEDIUM_HOST', 'https://miro.medium.com')
    imageURL = "#{miro_host}/#{previewImageFileName}"

    if ImageDownloader.download(absolutePath, imageURL)
      postInfo.previewImage = imagePathPolicy.getRelativePath(previewImageFileName)
    end
  end

  postInfo
end

.postGraphQL(operationName, queryString, variables) ⇒ Object 



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# File 'lib/Post.rb', line 85

def self.postGraphQL(operationName, queryString, variables)
  body = [{
    "operationName" => operationName,
    "variables" => variables,
    "query" => queryString
  }]

  host = ENV.fetch('MEDIUM_HOST', 'https://medium.com/_/graphql')
  response = Request.body(Request.URL(host, 'POST', body))
  return nil if response.nil?

  JSON.parse(response)
end

.postPageQueryString ⇒ Object 



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# File 'lib/Post.rb', line 81

def self.postPageQueryString
  @postPageQueryString ||= File.read(POST_PAGE_QUERY_PATH)
end

.postViewerEdgeContentQueryString ⇒ Object 



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# File 'lib/Post.rb', line 77

def self.postViewerEdgeContentQueryString
  @postViewerEdgeContentQueryString ||= File.read(POST_VIEWER_EDGE_QUERY_PATH)
end