DRYML: How to not show tag parameters that are empty

[Steve DeBaun]

<def tag="block">
<div class='block' merge-attrs>
<h3 param="title"/>
<h4 param="subtitle"/>
<h5 param="sidenote"/>
<p param="content"/>
<p param="footer"/>
</div>
</def>

How do I make it so tags without parameters passed don't get shown?
E.g. if I don't put a <subtitle:> tag, it still makes an empty <h4>
element.

I saw in the generated code stuff that put "if" at the end of the
parameter, so I tried that... at which point it stopped showing the
parameter everywhere.

sd

[Steve DeBaun]

Found the solution:

<h3 param="title" if="&all_parameters.title?"/>

It looked like if-content should work as shorthand for
if="&all_parameters.title?", but it didn't. I also expected
"&parameters.title?" to work, but it didn't.

sd

[Tom Locke]

all_parameters[:title] will be slightly more efficient. Your version
will actually evaluate the parameter and discard the result.

Tom