youtube-comments-task

youtube-comments-task

Scrape comments, including their replies, from a YouTube video.

Contents

• Installation
• Usage
• Comment Data
• Errors
• Task
• Compatibility
• Examples

Installation

npm install --save youtube-comments-task

Usage

The module exports a single function:

fetchComments(videoId[,pageToken])

The function accepts the YouTube videoId and an optional pageToken, and returns a Task that resolves to the corresponding page of comments. If the pageToken is not provided it fetches the first page of comments.

The result is an object with the following properties.

{
  comments: [ { comment }, { comment }, ... ],
  nextPageToken: 'nextpagetokenhere'
}

Note: If the fetched page is the last page, the result does not contain the nextPageToken property.

Comment Data

{
  id: {{ comment id}},
  author: {{ comment author name }},
  authorLink: {{ comment author link (channel) }},
  authorThumb: {{ comment author avatar thumb url }},
  text: {{ comment text }},
  likes: {{ comment up-votes }},
  time: {{ how long ago the comment was posted (relative, e.g. '1 year ago') }},
  timestamp: {{ timestamp when comment was posted in milliseconds (absolute, e.g. 1457661439642 }},
  edited: {{ whether the comment was edited by the authro (true/false) }},
  hasReplies: {{ whether the comment has replies (true/fasle) }},
  repliesToken: {{ token used to fetch replies for the comment }},
  numReplies: {{ number of replies }},
  replies: [ {{ reply objects (same fields as comments) }} ]
}

Errors

Errors are as descriptive and (hopefully) useful as possible. Private, deleted, and unavailable videos are detected, and an appropriate error type is assigned. Error types are defined in /src/lib/error-types.js.

A typical error object has the following fields.

{
  type: {{ error type }},
  message: {{ error message }},
  videoId: {{ YouTube video id }},
  component: {{ module component }},
  operation: {{ operation that failed }}
}

Task

The module uses Folktale's Task monad (data.task) to handle asynchronicity and to allow for easy composition.

If you'd rather use Promises instead of Tasks, check out youtube-comment-api.

Compatibility

The module is transpiled with Babel and is compatible with node.js versions >= 6.

Examples

const fetchComments = require('youtube-comments-task')

fetchComments('h_tkIpwbsxY')
  .fork(e => console.error('ERROR', e),
        p => {
          console.log('comments', p.comments)
          console.log('nextPageToken', p.nextPageToken)
        })

const Task = require('data.task')
const fetchComments = require('youtube-comments-task')

const fetchAllComments = (videoId, pageToken, fetched = []) =>
  fetchComments(videoId, pageToken)
    .chain(({ comments, nextPageToken }) =>
      nextPageToken
        ? fetchAllComments(videoId, nextPageToken, fetched.concat(comments))
        : Task.of(fetched.concat(comments)))

fetchAllComments('h_tkIpwbsxY')
  .fork(e => console.error('ERROR', e),
        allComments => console.log(allComments))