Trim [[ or trim ]] not working

[Sheridan Price]

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[<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

[Mat]

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

... trim:prefix<prefix>]"/>

<:-)

[Eric Shulman]

On Friday, December 17, 2021 at 7:54:00 AM UTC-8 sheri...@gmail.com wrote:

``` 

<$vars prefix="[[" suffix=" ]]">

<$list filter="[[smpConfig]get[animals]trim:prefix[<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?

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>]`

2) 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[]"/>`

3) 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

[Sheridan Price]

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<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