Problems with rss

[retroflex]

This is my first attempt at a module using a node_helper.js. My goal is to get an rss and output all rss items on the mirror. I have got the basics working, which is a function in node_helper.js which sends items over to the module js file:

loadFeed: function(url) {
    var items = [];
    items.push( { title: 'test title', description: 'test description' } );
    
    this.sendSocketNotification('ITEMS', {
      items: items
    });
},

Output:

But when I try to read and parse an rss, I get nothing… Code:

const FeedMe = require('feedme');
const http = require('http');

...

loadFeed: function(url) {
    var items = [];
    
    items.push( { title: 'before', description: 'before' } );
       
    http.get('http://www.npr.org/rss/rss.php?id=1001', (res) => {
      var parser = new FeedMe();
      parser.on('title', (title) => {
        items.push( { title: 'feedtitle', description: 'feedtitle' } );
      });
      parser.on('item', (item) => {
        items.push( { title: 'feeditem', description: 'feeditem' } );
      });
      res.pipe(parser);
    });

    items.push( { title: 'after', description: 'after' } );
    
    this.sendSocketNotification('ITEMS', {
      items: items
    });
},

Output:

“ls node_modules” show that both feedme and http is installed. No relevant errors in .pm2/logs/mm-error-0.log or mm-out-0.log.

So I tried with another rss parser:

const parser = require('rss-parser');

...

loadFeed: function(url) {
    var items = [];
    
    items.push( { title: 'before', description: 'before' } );
       
    parser.parseURL('http://www.npr.org/rss/rss.php?id=1001', function(err, parsed) {
      parsed.feed.entries.forEach(function(entry) {
        items.push( { title: 'entrytitle', description: entry.title } );
      });
    });

    items.push( { title: 'after', description: 'after' } );
    
    this.sendSocketNotification('ITEMS', {
      items: items
    });
},

Same output as above. No log errors. And rss-parser is installed in node_modules. Also this last code works fine in npm RunKit:
https://runkit.com/embed/q4ucjhbbzpw3

Any ideas what is failing? Or how to debug?

[Sean]

@retroflex I didn’t look inside deeply, but I think it might be caused by asynchronous problem.
I suspect sendNotification is performed before parsing rss(item.push)
Test it with console.log() before sendNotification and item pushing.

[retroflex]

@Sean Thanks! Logging shows your suspicions were correct:

MYMODULE Thu Nov 23 2017 09:43:15 GMT+0100 (CET): start of method
MYMODULE Thu Nov 23 2017 09:43:15 GMT+0100 (CET): end of method
MYMODULE Thu Nov 23 2017 09:43:16 GMT+0100 (CET): parsed an rss entry
MYMODULE Thu Nov 23 2017 09:43:16 GMT+0100 (CET): parsed an rss entry
MYMODULE Thu Nov 23 2017 09:43:16 GMT+0100 (CET): parsed an rss entry
...

Now I will try to find out if the rss parsers have a finished callback and put the sendSocketNotifications in there…

[retroflex]

To follow up… I got it to work by comparing parsed.feed.entries.length to the number of parsed entries, and when all entries were passed I called a callback that sent the notifications.

I’m new to javascript so there’s still a lot to learn.