Don't indent your code when testing for an empty variable

uli · 2011-09-08 01:08:02

Is that true?

I had the following code in a form, nicely indented:

<txp:variable name="aktuelles-tester">
  <txp:article_custom section="aktuelles">
    <txp:title />
  </txp:article_custom>
</txp:variable>

<txp:if_variable name="aktuelles-tester" value="">,aktuelles<txp:else /></txp:if_variable>

Which always returned “false”. Only when I removed any white space from the inner part of the variable the code worked. Logical, isn’t it? Or ist it just because I worked too much this night?

(But we’ve tons of if_variable code here in the forum. Did noone ever stumble upon it?)

Please enlighten me!

Last edited by uli (2011-09-08 01:16:19)

Gocom · 2011-09-08 06:32:29

uli wrote:

Is that true?

Yes. The contents of a variable is not trimmed from a white-space, or modified in any other manner. If you want to test the contents against empty, then you will need to make sure that there is no extra white-space, i.e. put everything to single line. For example, with your above example, the variable will have white-space as a content even when there are no articles.

If you remove white-space around article_custom and you are good to go:

<txp:variable name="aktuelles-tester"><txp:article_custom section="aktuelles" limit="1">
	<txp:title />
</txp:article_custom></txp:variable>

(But we’ve tons of if_variable code here in the forum. Did noone ever stumble upon it?)

Honestly, I haven’t really seen any incorrect variable code here on the forum, not saying that there isn’t. This is also the reason why I write my tips/examples to unreadable single line. It’s not because i want to, it’s because have to. Plus making the variable size smaller, decreases memory used by couple bytes.

jakob · 2011-09-08 09:09:16

It would be nice to have a trim attribute in there but in the meantime if you have really complex stuff in your variable you can also use one of Jukka’s other plugins:

<txp:variable name="aktuelles-tester"><txp:rah_function call="trim">

  <txp:article_custom section="aktuelles" limit="1">
    <txp:title />
  </txp:article_custom>

</txp:rah_function></txp:variable>

(a trick learnt from Jukka himself)

uli · 2011-09-08 11:49:10

Jukka, thanks for the clarification. That little bit of indentation inside the article tag should suffice most of the times. And if I need a whitespace spree I can always use your function plugin.

jakob, thanks for offering those continued sprees. And yes, a trim attribute would be nice. We’d still have to remember it (probably ;) but having it could serve an improved readability.

BTW Wouldn’t chh_if_data do the same job? And wasn’t there a way to replace chh_if_data with a var/if_var combo? Els, do you hear me? ;) <brain_loupe>To me these constructs always look like nails you’ve forgotten to countersink. This one would be a nail inside a nailhead. Cool!</brain_loupe>

els · 2011-09-08 20:53:29

uli wrote:

(But we’ve tons of if_variable code here in the forum. Did noone ever stumble upon it?)

It’s not a problem with if_variable, only with the txp:variable tag.

And wasn’t there a way to replace chh_if_data with a var/if_var combo? Els, do you hear me? ;)

This forum needs a Facebook/Diaspora/Google+-like mention feature ;) But why this question, because that is what you just did…

<txp:chh_if_data>
   <div><txp:tag /></div>
</txp:chh_if_data>

becomes

<txp:variable name="if_data" value='<txp:tag />' />
<txp:if_variable name="if_data" value="">
<txp:else />
   <div><txp:tag /></div>
</txp:if_variable>

A little bit longer, but much more flexible.

uli · 2011-09-08 22:17:33

Els wrote:

But why this question

Sorry if I made you feel like I urged you to post any code, wasn’t my intention. No, just that my mind began throwing sparks while thinking of removing white space off an otherwise empty variable with a second variable/if_variable construct.

This forum needs a Facebook/Diaspora/Google+-like mention feature ;)

Naaa, no, never! It lacks the human, the really social, component: to be sure that another person will read certain topics :)

hcgtv · 2011-09-08 22:50:30

uli wrote:

Naaa, no, never! It lacks the human, the really social, component: to be sure that another person will read certain topics :)

+1 ;)

On the subject of indenting code, I don’t like to indent template code on my sites. Where indenting code in a text editor will facilitate understanding of said code, when you copy/paste it into the backend, especially with size of the default textareas, it becomes rather confusing to maintain from that point on.

I know some prefer to use cnk_versioning or another method to code and maintain their sites, I prefer to work on the backend. And yet one of the gripes with Textpattern is that it keeps all template code in the database, which I don’t find to be a minus but rather a plus. To each his own I guess.

els · 2011-09-08 23:41:57

uli wrote:

Naaa, no, never!

+1 :) And to attract my attention writing ‘variable’ in the topic title will do… ;)

uli · 2011-09-09 12:59:42

Els wrote:

And to attract my attention writing ‘variable’ in the topic title will do… ;)

I lay claim to hold copyright for the following topic titles: “Variable me”, “Need variable”, “Variable!!!!” in any of its mean derivative forms. Hope that helps stopping a plague of annoying titles popping up.

NicolasGraph · 2016-07-25 12:17:29

Releated GitHub issue.

Textpattern CMS

Textpattern CMS support forum

#1 2011-09-08 01:08:02

Don't indent your code when testing for an empty variable

#2 2011-09-08 06:32:29

Re: Don't indent your code when testing for an empty variable

#3 2011-09-08 09:09:16

Re: Don't indent your code when testing for an empty variable

#4 2011-09-08 11:49:10

Re: Don't indent your code when testing for an empty variable

#5 2011-09-08 20:53:29

Re: Don't indent your code when testing for an empty variable

#6 2011-09-08 22:17:33

Re: Don't indent your code when testing for an empty variable

#7 2011-09-08 22:50:30

Re: Don't indent your code when testing for an empty variable

#8 2011-09-08 23:41:57

Re: Don't indent your code when testing for an empty variable

#9 2011-09-09 12:59:42

Re: Don't indent your code when testing for an empty variable

#10 2016-07-25 12:17:29

Re: Don't indent your code when testing for an empty variable

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