Managing Time in Yahoo Pipes

In the previous post – OU News Tracking – I briefly described how to get a Yahoo pipe to output a “pubDate” timestamp in the “correct” RSS standard format:

Here’s the full expression (actually, a PHP strftime expression) for outputting the date in the required RFC 822 date-time format: %a, %d %b %Y %H:%M:%S %z

The Date Builder block is being applied to a particular field (cdate) in every feed item, and assigning the results to the y:published tag. But what exactly is it outputting? A special datetime object, that’s what:

The Date Builder module is actually quite flexible in what it accepts – in the above pipe, cdate contains values like “21 August 2008”, but it can do much more than that…

For example, take the case of the THES search pipe, also described in the previous post. The pipe constructs a query that searches the Times Higher from the current date back to the start of the year. Heres what the query looks like in the original search form:

And here’s what the URL it generates looks like:

http://www.timeshighereducation.co.uk/search_results.asp?
refresh=0&keyword=%22open+university%22&searchtype=kyphase&sections=0&categories=0
&dateissuefilter=datefilter&issue=0
&sday=1&smth=1&syr=2008&eday=4&emth=9&eyr=2008

sday is “start date”, emth is “end month”, and so on…

Posting the URL into the Pipe URL builder separates out the different arguments nicely:

You’ll notice I’ve hardcoded the sday and smth to the January 1st, but the other date elements are wired in from a datetime object that has been set to the current date:

Terms like “now” also work…

Taken together, the two date/time related blocks allow you to manipulate time constructs quite easily within the Yahoo pipe :-)