fb-page-comment-event

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Description

This module can keep track your Facebook page posts' first level comment events. Hence, if someone commented on your post, you will be notified by an event.

This module support running an event-engine which would manage a background schedule job to check new comment and generating events. This module also support raw APIs which you can check new comments and digest as events by yourself via APIs.

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Running the event engine

You may use the lib.pageCommentEventApp(options) API to get a event engine app and then start it with run function. This event engine app would manage a schedule job to auto pull data.

Sample:

'use strict';
 
let fbPageCommentEventLib = require('fb-page-comment-event');
 
const pageCommentEventApp = fbPageCommentEventLib.pageCommentEventApp({
    accessToken: 'EAASHAlSbbMUBALwwZCxZB1T7eDvFZBR......GQfNPb5Bxo5b2wdzMb45gJxcdZAFOQZDZD',
    pullInterval: 15 * 1000
});
 
pageCommentEventApp.registerMonitorPost({ pageId: 'xxxxx', postId: 'yyyyy' });
 
pageCommentEventApp.run((events) => {
    console.log(JSON.stringify(events, null, 2));
    return;
});

• Remarks: pageId is the facebook page ID. postId is the facebook page post ID of post which you want to monitor its comment. accessToken is the Facebook page access token(remember to use the long live token) which Facebook page owner can generate in developer dashboard.

Sample console log output:

>node sample.js
{"message":"2017-12-21T19:18:48.701Z: Fetching feed items with comments newer than lastScannedCommentTime(2017-12-21T19:14:18.000Z).","level":"info"}
{"message":"2017-12-21T19:18:48.960Z: Fetched and filtered and returning 1 feed items which containing new comments. \"newLastScannedCommentTime\" reset to 2017-12-21T19:14:18.000Z.","level":"info"}
[
  {
    "eventType": "comment",
    "data": {
      "postId": "xxxxxx",
      "commentId": "yyyyyy",
      "from": {
        "name": "zzzzzz",
        "id": "aaaaaa"
      },
      "commentCreateTime": 1513883658000,
      "message": "test comment",
      "link": "https://www.facebook.com/permalink.php?story_fbid=xxxxxx&id=aaaaaa&comment_id=cccccc"
    }
  }
]

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(DIY) Use the APIs to check new comments and generating events

Sample:

let fbPageCommentEventLib = require('fb-page-comment-event');
 
let pageId = 'aaa';
let postId = 'bbb';
let accessToken = 'XXX...ZZZ';
 
let postDigestor = lib.api.getPostDigestor();
 
let since = Math.trunc(Date.now() / 1000) - 10 * 60; //since 10 minutes before
 
(async function () {
 
    let queryPostCommentAgent = lib.api.getQueryPostCommentAgent({ accessToken }); //initialize query agent with access token
    let postCommentFetcher = lib.api.getPostCommentFetcher(queryPostCommentAgent); //initial comment fetcher
 
    let postWithNewComments = await postCommentFetcher.fetch(`${pageId}_${postId}`, since); //fetch target post with new comments
    let postWithNewCommentEvents = await postDigestor.digest(postWithNewComments); //digest the post object into new comment events
 
    console.log(`postWithNewCommentEvents: ${JSON.stringify(postWithNewCommentEvents, null, 2)}`);
})();
 

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event engine APIs

let app = lib.pageCommentEventApp({accessToken, pullInterval})

Description:

Initializing the event engine app.

parameters:

• accessToken: The required accessToken(need permission manage_pages) for the API calls.
• pullInterval: The sleep time(ms) interval between each scheduled page post new comment checking.

return:

The event engine app.

app.registerMonitorPost({pageId, postId})

Description:

Registering a page post which the event engine would tracking for new comments

parameters:

• pageId: The page ID.
• postId: The post ID.

app.run(eventsCallback)

Description:

Start running the event engine and register the new-comment-events callback. Once users write new comments, new-comment-events would be fired and handled by the callback.

parameters:

• eventsCallback: The batch new-comment-events handling function.

app.stop()

Description:

Stop the event engine

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DIY APIs

let queryPostCommentAgent = lib.api.getQueryPostCommentAgent(options)

Description:

Initialize a agent for query post comments.

parameters:

• options: object with attribute accessToken which holding the required accessToken(need permission manage_pages) for the API calls.

return:

The agent object.

let postCommentFetcher = lib.api.getPostCommentFetcher(queryPostCommentAgent)

Description:

Initialize a fetcher for fetching new post comment.

parameters:

• queryPostCommentAgent: The agent object which come from lib.api.getQueryPostCommentAgent(options)

return:

The fetcher object.

let postCommentObj = await postCommentFetcher.fetch(postObjId, since)

Description:

Use the fetcher object to fetch post object with comments. We can use this API to get all new comments under the target post which those comments are created since the since time.

parameters:

• postObjId: The post object ID which is in format of ${pageId}_${postId} in Facebook Graph API.
• since: The timestamp in second

return:

The post object with comments (All comments child objects are new comments).

let postDigestor = lib.api.getPostDigestor();

Description:

Getting a digestor object which can turn the post-comment object from postCommentFetcher.fetch() result into new-comment-events.

return:

The digestor object.

let newCommentEvents = await postDigestor.digest(postWithNewComments)

Description:

Use the digestor object to digest post-comment object into new-comment-events

parameters:

• postWithNewComments: The post object with attaching new comments.

return:

New comment event objects

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Author

• Eric Yu: [e-mail]