[tw5] Trim [[ or trim ]] not working

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#1

Hello
I am new to TW so I won’t be surprised if the answer is obvious in retrospect.
I have:

<$vars prefix="[[" suffix=" ]]">
<$list filter="[[smpConfig]get[animals]trim:prefix[]]"/>
</$vars>

If I don’t have the trim part then the output is: [[Fox ]] [[Beaver ]]… all good but once the trim is added there is no output.

So what silly error am I making?

The intent behind this is as part of a larger activity (naturally) that will take the resulting list of animals and find all tiddlers that have a field with that animal name. A tiddler could have none, some or all of the animal names as fields. I believe I can figure out the rest or at least have fun trying but this trim problem has me beat. I have checked the documentation, google searching and here to no avail. Help as they say

Regards
Sher

#2

I didn’t try out your code but it looks like a simple syntax error. Try:

… trim:prefix]"/>

<:-)

#3

A couple of things:

  1. The brackets surrounding a filter operand are actually part of the operand itself, and indicate the kind of operand to process:
  • square brackets enclose literal values
  • angle brackets enclose variable references
  • curly braces enclose tiddler references

Thus, you want to write: trim:prefix<prefix> instead of trim:prefix[<prefix>]

  1. The get[foo] syntax returns the value in the field named “foo” as a single block of text. To handle the retrieved value as a space-separated, bracketed list of items, you should use the enlist-input[] filter operator, like this:

<$list filter="[[smpConfig]get[animals]enlist-input[]"/>

  1. Your example list, retrieved from the field named “animals”, seems to include trailing space for each animal name. I suggest omitting the extra spaces in the field content. Alternatively, you can use trim:suffix[ ] in your filter, like this:

<$list filter="[[smpConfig]get[animals]enlist-input[]trim:suffix[ ]]"/>

enjoy,
-e

2 Likes
#4

I hope I did this reply correctly (I used reply all).

So I tried it out and for the sake of anyone else who might read this in the future here goes.

Trim works if written as trim:prefix Thanks to both Eric and Matt for their response.

As Eric mentions as given in the original post the filter will produce a single block of text that the trim sees as a single “word” to trim so only the leading [[ is removed for trim prefix and the very last ]] is removed for the trim suffix. If the enlist-input[] is included then the filter works as desired outputting a list of just the animal names with no brackets [[ ]] at all to be seen surrounding them. Thanks Eric for that. Also thank you for the explanation on bracketing in filter expressions. I knew of it but hadn’t integrated it properly into my brain. This problem and your explicit mention of those syntaxes has now done that.

Thank you both
Regards
Sher