Sometimes you’ll want to use Textpattern articles as events. A common approach is to use Textpattern’s “Posted Date/Time” field to store date/time information about the event. For example, user “totoff” at the TXP forums was using the <txp:posted /> tag to output the time of a vernissage (a private viewing that occurs before a gallery opening). He wanted to show only articles where the time wasn’t set to “00:00”, because this is the default setting and would indicate that there was no vernissage.

Our goal is to compare the posted date with the value “00:00” and see if there’s a match. If there is a match, there is no vernissage, so we’ll do nothing. If there is a mismatch, it means there is a vernissage, and we’ll output the vernissage data.

Store the information in a variable

First, let’s store the posted information in a variable, so that we can compare it later. One trick I learned about variables from Stef Dawson is that you can use them as a container tag, like so:

<txp:variable name="vernissage_time"><txp:posted format="%H:%M" /></txp:variable>

That creates a new variable called “vernissage_time” and sets its value to the posted date/time as “HH:MM” (Hours/Minutes).

Check the content of the variable

Next, we want to use <txp:if_variable> to check if vernissage_time is set to 00:00.

<txp:if_variable name="vernissage_time" value="00:00">

If that’s true, let’s do nothing. I like to put a comment in, like this:

<!-- no vernissage -->

Then let’s use the <txp:else /> statement for when we’ve got a time that’s different than “00:00” and thus a vernissage is being held:

<txp:else />
		<h2>Vernissage Time:</h2>
		<p><txp:variable name="vernissage_time" /></p>
	</txp:if_variable>

That’s done it! Here is the complete code:

<txp:variable name="vernissage_time"><txp:posted format="%H:%M" /></txp:variable>
<txp:if_variable name="vernissage_time" value="00:00">
	<!-- no vernissage -->
<txp:else />
	<h2>Vernissage Time:</h2>
	<p><txp:variable name="vernissage_time" /></p>
</txp:if_variable>