Self-closed versus container tags
Contents
Self-closed tags
A self-closed tag is the most basic form of a Textpattern tag. Its structure is similar to that of a self-closed tag in HTML (e.g. <br />), most notably the inclusion of the terminating forward slash.
Any self-closed Textpattern tag has the following syntactic structure:
<txp:tagname />
The tag is replaced by contents when Textpattern displays a page.
Self-closed tags can usually take attributes. For example, the following article tag demonstrates using the form and limit attributes:
<txp:article form="formName" limit="15" />
Most Textpattern tags are self-closed tags. The other type of tag is the container tag.
Container tags
Container tags are composed of both an opening and closing tag element, giving them the syntactic structure of:
<txp:tag_name>
…content…
</txp:tag_name>
The content that is added between container tags may be either text or other Textpattern tags.
Typical container tags are the permlink tag <txp:permlink></txp:permlink> and all conditional tags. Container tags are used when something has to be enclosed by tags instead of being replaced by them.
A link is a good example: you have a text string (or a title tag) around which you want to wrap an HTML anchor element:
<txp:permlink>
<txp:title />
</txp:permlink>
…content…
<txp:permlink>
Read more…
</txp:permlink>
The example above would be rendered into something like so:
<a href="/articles/this-article-title">This article title</a>
…content…
<a href="/articles/this-article-title">Read more…</a>
Closing tags correctly
Textpattern tags behave like XML tags insofar as they must be closed correctly. Any containing tag must have both an opening tag and a corresponding closing tag (marked with a preceding slash):
<txp:some_tag>
…content…
</txp:some_tag>
If the tag is a conditional tag, check to make sure that any else tag is employed correctly:
Right:
<txp:if_some_condition>
…true branch…
<txp:else />
…false branch…
</txp:if_some_condition>
Wrong:
<txp:else>
</txp:else>
</txp:else />
Single (self-closing) tags must have a single slash at the end:
<txp:some_single_tag with="attributes" />
Also check that the angle brackets have not been HTML encoded by mistake, e.g.:
<txp:some_tag />