Extract Function

RE: Extract Function

Shanmathi Ponnusamy — Tue, 11 Jul 2023 07:12:50 GMT

Can you please check if the below code works for your use case?

a!localVariables(
  local!values: split(ri!myString, "["),
  local!valuesWithCloseBracket: reject(
    a!isNullOrEmpty,
    a!forEach(
      items: local!values,
      expression: if(search("]", fv!item) > 1, fv!item, null)
    )
  ),
  a!forEach(
    items: local!valuesWithCloseBracket,
    expression: split(fv!item, "]")[1]
  )
)

RE: Extract Function

michelek1257 — Tue, 11 Jul 2023 06:48:45 GMT

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RE: Extract Function

Mike Schmitt — Mon, 10 Jul 2023 14:20:42 GMT

nice try...

RE: Extract Function

flaughers9083 — Mon, 10 Jul 2023 11:45:02 GMT

[deleted]

RE: Extract Function

Vaithyanathan Raju — Mon, 10 Jul 2023 10:03:12 GMT

Hi Stewart Burchell - Even if we have even number of "[" and "]" will it be only taking first combination of the same?

extract(
  "[This [is [the] Test] String]",
  "[",
  "]"
)

RE: Extract Function

Abhay Dalsaniya — Wed, 15 Mar 2023 21:49:16 GMT

May be it make sense to the other person on how the exact() function works, because the the original post and subject mentions about extract() function.

RE: Extract Function

Mike Schmitt — Wed, 15 Mar 2023 19:44:37 GMT

not sure what the point of this is - this doesn't have much to do with the error the user describes.

RE: Extract Function

Abhay Dalsaniya — Wed, 15 Mar 2023 19:35:24 GMT

extract() Returns the value (or values, if the text contains multiple delimited values) between the delimiters from the given text.	`extract( "name: Bob, name: Karen, name: Sam", ":", "," )`

RE: Extract Function

tejashwinin0822 — Wed, 15 Mar 2023 18:47:10 GMT

a!localVariables(
local!datacontent: fn!char(
fn!code(ri!text)
),
local!sum: a!forEach(
items: local!datacontent,
expression: a!match(
value: fv!item,
equals: "[",
then: 1,
equals: "]",
then: - 1,
default: 0
),

),
local!totalSum: fn!sum(local!sum),
local!statusCode: if(local!totalSum = 0, 1, 0),
local!result: union(
if(
local!totalSum = 0,
fn!extract(
ri!text,
"[",
"]"
),
""
),
touniformstring({})
),
{
if(
local!statusCode = 1,
"",
"Number of open square brackets and close square brackets must be equal"
),
if(
a!forEach(
items: local!result,
expression: find("[", fv!item)
),
"No square brackets is allowed between [ and ]",
""
)
}
) in addition to your solution just added find("[", fv!item) this to validation to prevent "[" in between open and close square brackets Thanks Stewart and Mike for you time and suggestion

RE: Extract Function

Mike Schmitt — Wed, 15 Mar 2023 16:25:55 GMT

[quote userid="3520" url="~/discussions/f/general/28090/extract-function/109484#109484"]Open to suggestions how to achieve a true parser here...?[/quote]

It's hard to say, really - there are too many unanswered questions about what the source data might be, and those things are required in order to form the initial assumptions behind a robust parser. Without wasting the time actually trying, i'd guess it might be easier to make an exact one using regEx matching, though checking for potentially unlimited repeats can get pretty frustrating there.

RE: Extract Function

Stewart Burchell — Wed, 15 Mar 2023 16:07:54 GMT

Yeah, I'm not convinced...a true parser would ensure that every opening "[" had a corresponding "]". The "parser" above just ensures there's an even number, which isn't the same. Open to suggestions how to achieve a true parser here...?

RE: Extract Function

Mike Schmitt — Wed, 15 Mar 2023 16:00:37 GMT

That's a neat little parser. I would have probably just resorted to splitting the original string on "[", then checking the members of the resulting array for the presence of "]" (i.e. each having at least 1 and only 1), and handling from there.

RE: Extract Function

Stewart Burchell — Wed, 15 Mar 2023 16:00:10 GMT

There isn't. So you have to get creative. See above responses.

RE: Extract Function

tejashwinin0822 — Wed, 15 Mar 2023 15:56:30 GMT

i went through all the functions but couldnt find the exact function to count number of"["

RE: Extract Function

Mike Schmitt — Wed, 15 Mar 2023 15:55:22 GMT

yeah, you're right - i realized right after.

so i guess we have to resort to a simple workaround like len(cleanwith(local!myString, "[")) - which will extract only that character from the original string then return the length of the result.

RE: Extract Function

Stewart Burchell — Wed, 15 Mar 2023 15:54:19 GMT

Um...find() only returns the first instance. Frustratingly (since it's such a common use case) there's no function that I'm aware of to count the instances of a string within a string, hence the heavyweight example I've provided.

RE: Extract Function

Stewart Burchell — Wed, 15 Mar 2023 15:51:59 GMT

Not directly, no. You have to break up the string into an array containing its individual characters and then you can count. Here's something that I played with:

a!localVariables(
  local!stringAsArray: fn!char(fn!code(ri!myString)),
  local!scoring: a!forEach(
    items: local!stringAsArray,
    expression: a!match(
      value: fv!item,
      equals: "[",
      then: 1,
      equals: "]",
      then: - 1,
      default: 0
    )
  ),
  local!scoreSum: fn!sum(local!scoring),
  local!statusCode: if(local!scoreSum = 0, 1, 0),
  local!result: if(
    local!scoreSum = 0,
    fn!extract(ri!myString, "[", "]"),
    "INPUT ERROR"
  ),
  a!map(
    statusCode: local!statusCode,
    result: local!result
  )
)

Explanation:

fn!char(fn!code(ri!myString)) generates the array of individual characters as described
the a!forEach() then assigns a score for each character
we then sum the individual scores - if there are an even number of "[" and "]" the score will be zero
we then return an a!map() with the result. This contains a statusCode to indicate if the original string was valid or not, and a result

Hope this makes sense

RE: Extract Function

Mike Schmitt — Wed, 15 Mar 2023 15:51:35 GMT

you'll want to check out standard appian expression functions ~~like "find()"~~ to help with that.

edit: find() doesn't actually work for this (grumble) but i believe my example below will.

RE: Extract Function

tejashwinin0822 — Wed, 15 Mar 2023 15:46:14 GMT

will definetly try this Thank you for the quick response

RE: Extract Function

tejashwinin0822 — Wed, 15 Mar 2023 15:45:06 GMT

Is there any function to count the number of "["

RE: Extract Function

Stewart Burchell — Wed, 15 Mar 2023 15:35:37 GMT

...of course if you treat "[" and "]" as just pure delimiters then you can do something like this, which isn't sensitive to the need for each "[" to have a matching "]"

fn!reject(
  a!isNullOrEmpty,
  a!flatten(
    a!forEach(
      items: split(ri!myString, "["),
      expression: split(fv!item, "]")
    )
  )
)

RE: Extract Function

Stewart Burchell — Wed, 15 Mar 2023 15:17:12 GMT

I would encourage you to validate the incoming string before you attempt to use the extract() function on it. There are probably a few ways to do this but in essence if you check that the string you want to process contains an even number of "[" and "]" characters then you'll avoid the error. What might be a bit harder to achieve is to ensure that every "[" has a following "]" without another intervening "["...if that even matters to you? But the principle here: don't attempt to process data that is effectively invalid.