Questions on building RSS feed - rss

I am building RSS feed for the first time and I have some simple, direct questions that I was unable to find on the web, well at list in a sense that would be clear to me. Can you help me understand following
Which items should I include in RSS generation? should I always put in all the articles or what is the criteria when I query my articles for the feed?
What value should I set for pubDate? The specification says "The publication date for the content in the channel. For example, the New York Times publishes on a daily basis, the publication date flips once every 24 hours. That's when the pubDate of the channel changes.". I do not quite understand how to apply this to my feed. I have new articles daily, should I set the pubDate to let say 06:00 AM today and update it every day?
lastBuildDate: if I understand this right is the date of the latest updated item?

Which items should I include in RSS generation?
You should have one generic feed with all the new articles you post (for example: news). Additionally if you got your webpage split into categories, or you have some specific feeds (eg. calendar of the events) then it's good to create additional separate RSS for each one of them
What value should I set for pubDate? I do not quite understand how to apply this to my feed. I have new articles daily, should I set the pubDate to let say 06:00 AM today and update it every day?
Always set pubDate to the time when your news/articles went online. So if you have new articles daily pubDate should be a date when they were released to the public. Not random hour in the morning. Not the moment when you started writing them.
lastBuildDate: if I understand this right is the date of the latest updated item?
lastBuildDate is the most recent date when any of the results was posted or modified. Usually you should skip it - especially if your lastBuildDate will be simply a most recent pubDate. It's an optional parameter.
I use lastBuildDate only for calendar RSS feeds to show when the calendar was updated (as in calendars you not only add new entries but also often edit existing).

You should put every article, but the best is to provide different feeds for different categories, even search keywords. You can build it like any dynamic page, with a querystring.
that's not super important, you can put whatever. I don't think may feed readers use it.
theoretically it's the date the content changed. So the date of the latest updated item should work.
Something super important, since people are going to do polling on this page (meaning a lot of requests on the page)
- Cache it on your server
- Serve and Etag header and/or a LastModifiedDate. That way your server can respond with just a "not modified" if the client has it in cache already.

Related

Automatically including posts from the last seven days inside a FEEDBLOCK for a MailChimp RSS Campaign

So, I'm working on trying to improve a Mailchimp RSS campaign that was created by one of my coworkers.
The email that gets sent out is a list of posts from different categories in our website.
So to do this the RSS campaign is made up of different FEEDBLOCKS – one FEEDBLOCK for each kind of category on the website. An example of one of the FEEDBLOCKs looks like this (which is pretty standard and basic, I guess):
*|FEEDBLOCK:http://website.com/specific-category/feed|*
*|FEEDITEMS:[$count=2]|*
*|FEEDITEM:TITLE|*
*|END:FEEDITEMS|*
*|END:FEEDBLOCK|*
The thing I want to fix is for the FEEDBLOCK to only show new posts from the past 7 days (the Mailchimp campaign goes out once a week). At the moment, we do this manually by changing the number in the *|FEEDITEMS:[$count=2]|* field. We have to manually count the number of new posts on the website each week and input the new count number so the correct number of new posts are displayed on the email.
I'm pretty new to using RSS feeds and Mailchimp but it seems to me from knowing some basic coding that there should be a way to do this automatically, rather than having to manually change the count number for every FEEDBLOCK before we send out the email to our subscribers.
Can any of you give me any advice on how I can change the code we're using to update the count number automatically?
Thanks in advance!
I'm not entirely sure this is how Feedblock works - but with the standard RSS merge tags available in Mailchimp, the schedule of the email determines how many items are pulled in. For example, I have an rss feed scheduled for once a week - with no item number parameters the code - Mailchimp pulls in only the articles posted to my feed since the last time the campaign sent - i.e. in one week it can be anywhere from 3 to 10.
I am trying to do the same thing. FEEDBLOCKS and FEEDITEMS do not act like RSSFEED and RSSITEMS. If you use FEEDBLOCKS the RSS dates entered in the "RSS Feed" step are not used!
This is what I received from MailChimp: "Any FEEDBLOCK tag in a sense will be its own feed so any dates set for the RSS campaign are ignored. FEEDBLOCK's are usually used for non-rss campaigns to display something from another feed. You can only control how many post are shown when using the FEEDBLOCK tag."
Unfortunately I, like you, have only the manual solution! I am not a coder, but I think the rssfeed itself has to be changed. That would be to build an RSS feed that limits entries to a certain date range i.e., previous 7 days ending with previous full day.

How to detect updates in podcast feeds?

I have a large set of podcast feed URLs which I'm periodically polling to check for updates. I'm really struggling to find a robust way to detect if a feed has changed that doesn't have any false positives. I'd like to be able to detect not just if there is a new episode, but also if an existing episode was updated.
RSS and Atom feeds provide pubDate, lastBuildDate or updated elements. However, I'm finding these frequently misused so that the feed is actually inserting the current date time into these fields each request. This makes them difficult to rely on to detect changes.
My next thought was to strip all date information from the podcasts, then MD5 hash the feed contents. I can then compare the feed hashes to detect changes to the feeds.
This seems to work for about 90% of the cases. However, there are still hundreds of podcasts that insert dynamic data into their feeds.
One podcast has the following as their podcast cover art:
http://erikglassman.hipcast.com/albumart/1000.1439649026.jpg
Where 1439649026 is what I assume is a timestamp. This second number changes with each request of their feed.
This is starting to seem like a losing battle. If I can't reliably trust the date fields of a podcast feed, and if some percentage of podcasts insert dynamic data into their feed text, how can I reliably detect changes to a feed in a robust way?
Everything you say is true, so it's not a good idea to try to detect changes at the feed level, instead look for them at the item level.
That generally works, if it doesn't the feed can't be used by anyone, so the source of the feed is likely to have fixed any problem. That's why I think it works so well.
I've been writing feed readers as long as they have existed, my current product is called River4, it's available as open source, MIT License, so you can use it as example code, for this and other issues.
This is where it checks if an item is new:
https://github.com/scripting/river4/blob/master/river4.js#L1411
That might move around as the code changes, so look for a routine called getItemGuid. It shows you how to get a value that uniquely identifies the item. I use this code for my podcatcher, http://podcatch.com/, and it seems to catch the new items, and doesn't get false positives.
Hope this helps! :-)

RSS for Future Items

This may be a simple question, but for some reason I don't know this answer. Is it possible to create an RSS feed file that contains contents for an entire year but only publishes the current date and previous date information?
I have a client that wants to do a "this day in history" post. Currently, I am using IFTTT, and created around sixty dated posts for the next two months. Of course, this works -- but it is very labor intensive.
Is it possible to create an RSS feed that you could put all 365 days of data in to, but if someone pulls up the feed it only shows today's item and prior days in the feed?
Or is RSS not the proper technology to do this? The reason I am using RSS is for ease of use, and IFTTT will take those RSS feeds and pump it in to Facebook and Twitter for automatic status updates for my client.
There are various tools that let you define Facebook and Twitter posts in advance, to be published at a specified date and time in the future. Why not use one of those instead of writing your own?
A quick search for "scheduled twitter post" uncovered Later Bro, Twuffer and twAitter but there must be dozens to choose from.
If you're looking for just posting on Facebook and Twitter, and not an RSS feed as well, I'd follow Matthew's suggestion. If you want an RSS feed, there is a feed for each Twitter feed. But if you want actual RSS, you need to add something in between. An RSS feed is just an XML file. it's not a process. I suggest having a file of some type (maybe RSS, or other XML, or a database table, or even a csv file with all the posts and relevant information, including date. Then a small script that runs as a chron job (or IFTTT if it supports date as trigger and running a script as the "then" part) that pulls the day's feed and updates the actual RSS feed. Pretty simple.
Here is what I ended up doing
Using the Drupal backend of my website, I created a content type specifically for these posts.
I created individual articles for each day, and used the schedule module to schedule the publish date to the date I wanted.
I created an RSS feed of these posts through Drupal.
I linked the newly created RSS feed to IFTTT.
Created an IFTTT recipe to post the text from the RSS feed to Facebook/Twitter/etc.
It wasn't the best solution, but it worked. I was really trying to do this without having to rely on a third-party such as IFTTT, but never really figured out a good way to do it.

Reading RSS by publication date

I want to build an RSS reader for twitter RSS feeds (c# .NET 3.5).
Getting a response from RSS web address and parsing it is very simple. (I did that with XmlDocument.Load("<RSS Feed>")).
The problem is that I need to get RSS items by publication date range.
When loading the application, I want to get all the items since the last time the feeds have been downloaded.
How can I do this?
Does every RSS feed allow that? (Google reader is showing items even from the last year).
It comes down to two sources of data: what the feed currently provides, and what you have stored.
If the feed is only showing the 10 most recent, for example, there is nothing you can do to get the older data. The feed must provide it.
Google Reader runs a cronjob that checks feeds about every 3 hours. It then stores the items in a database for Google Reader to reference any time it needs.

What is the difference between <pubDate> and <lastBuildDate> in RSS?

I have the feeling, in every RSS.xml file, both the pubDate and the lastBuildDate match.
I am sure that this one, is not always true...
So firstly, what is the difference between those two above?
Secondly, the RSS readers, sort the content by Date, based on the pubDate or the lastBuildDate?
pubDate:
The original publication date for the channel or item. (optional)
lastBuildDate:
The most recent time the content of the channel was modified. (optional)
Here are some docs for the optional items in the RSS 2.0 spec.
Answers here are all over the place. Some people are getting confused by the fact that item has a pubDate as well. I believe the OP is specifically asking about the difference between lastBuildDate and pubDate at the channel level.
From the best of my understanding of the RSS spec, which is notorious for ambiguous explanations, lastBuildDate would be the last time the feed was created. For example, if you cache a copy of it on your server for some period of time, lastBuildDate would the time that cached copy was created.
pubDate, on the other hand, seems to be basically the last time any actual content within the feed has changed. For the most part it's pretty much going to be the latest pubDate value from the items in the feed, since generally, the feed content is only changing when some new item gets published. However, it could also be a date when you made some change to the channel, itself, such as changing the channel title, description, etc.
lastBuildDate specifies the last date/time the entry was modified. pubDate specifies the actual publication date/time.
The reason you see these as generally the same is because by the time you get the RSS feed, there hasn't been any edit to the article.
I can't find the RSS spec on this unfortunately, but I am pretty positive that's what they are.
By RSS 2.0 specification, it seems they are roughly equivalent:
lastBuildDate:
The last time the content of the channel changed.
pubDate:
The publication date for the content in the channel. ...
The difference is subtle: They tell us about the method that was used. In case of <pubDate>, the channel is published manually or in fixed period. In case of <lastBuildDate>, the channel is built automatically upon new article being added on the website, adding it as new item.
While the other answers here do provide some good information, I feel the need to elaborate just a little bit for any future visitors.
pubDate
The publication date for the content in the channel. For example, the New York Times publishes on a daily basis, the publication date flips once every 24 hours. That's when the pubDate of the channel changes.
lastBuildDate
The last time the content of the channel changed.
So, taking the New York Times as an example again, the <pubDate> is the date the feed was published while the <lastBuildDate> would be the date the content inside the feed changed. In the end, I would view the <pubDate> as the date the feed is published and the <lastBuildDate> as the date any content in the feed was last modified.

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