Forcing a pattern in textfield using regex

[KDAI]

I am trying to validate my text field with some regex pattern

here is the sample text 

ABC-D-2013/07/15-1115

or 

DEF-N-2012/07/15-2224, BOY-W-2018/05/16-4441

this is my code

If(
IsMatch(
e_url.Text,
"([a-zA-Z]+-[a-zA-Z]+-\d+\/\d+\/\d+-\d+(?:,\s*[a-zA-Z]+-[a-zA-Z]+-\d+\/\d+\/\d+-\d+)?)",
MatchOptions.Complete
),
Color.White,
Color.Red
)

I am trying to change the fill color to red if it doesn't match.

it is always red. 

is the code right?

[Chris-D]

Hi @KDAI, I think there's an error in your Regex. There's an open bracket at the start which doesn't seem to have a close bracket to match. 

Try this Regex though, it might work better:

([a-zA-Z]+-[a-zA-Z]+-\d+\/\d+\/\d+-\d+(,\s)*)+

This doesn't seem to validate the amount of letters/numbers though, any combination will validate as long as there is at least 1 letter/number. 

This would be valid: QWERTY-UIOP-1/2/3-9999999999999999, BOY-W-2018/05/16-4441

[KDAI]

Did work half way through, now i need the numbering part. 

If(
IsMatch(
e_url.Text,
"([a-zA-Z]+-[a-zA-Z]+-\d+\/\d+\/\d+-\d+(,\s)*)+",
MatchOptions.Complete
),
Set(
varvisible,
false
),
Set(
varvisible,
true
)
)

i added a label with text and set the visible value to it. 

[MudassarSZ365 · Accepted solution]

Hi @Chris-D ,

try this

The adjusted regex pattern with additional parentheses around the whole pattern could be:

"^([a-zA-Z]+-[a-zA-Z]-\d{4}\/\d{2}\/\d{2}-\d{4}(?:,\s*[a-zA-Z]+-[a-zA-Z]-\d{4}\/\d{2}\/\d{2}-\d{4})*)$"

So the IsMatch function in Power Apps would be:

If(
    IsMatch(
        e_url.Text,
        "^([a-zA-Z]+-[a-zA-Z]-\d{4}/\d{2}/\d{2}-\d{4}(?:,\\s*[a-zA-Z]+-[a-zA-Z]-\d{4}/\d{2}/\d{2}-\d{4})*)$",
        MatchOptions.Complete
    ),
    Color.White,
    Color.Red
)

[Chris-D]

Hi @KDAI, 

I'm not sure what this means? 

"now i need the numbering part"

[KDAI]

that means this is the pattern

ABC-D-2013/07/15-1115 

with exact number of characters in between

[Chris-D]

ok we can do this with a couple of things. 

First I'm going to remove the 2 cases from the character matches. You should add IgnoreCase to your match options, it makes the Regex clearer to read. 

([A-Z]{3}-[A-Z]-\d{4}\/\d{2}\/\d{2}-\d{4}(,\s)*)+

// Let's break it down
(
    [A-Z]{3} - match A-Z, exactly 3 times
    -hyphen-
    [A-Z] - match A-Z but only a single character (removed the +)
    -hyphen-
    \d{4} - match a digit, exactly 4 times
    -hyphen-
    \d{2} - ... but twice
    -hyphen-
    \d{2} - ... but twice
    -hyphen-
    \d{4} - ... and 4 times again
    (
        , - a comma
        \s - single whitespace (could break, might be tab or newline but unlikely in your case)
    )* - * = match this bit 0 or more times - it may or may not be present
)+ - match the whole thing at least once

That should be pretty bombproof for you and I hope my explanation is clear. I should question though why you are validating your output? The content should be validated when it's input. 

[KDAI]

I already did this with following 

    ^([a-zA-Z0-9]{3,4}-[a-zA-Z]-\d{4}\/\d{2}\/\d{2}-\d{4}(?:,\s*[a-zA-Z0-9]{3,4}-[a-zA-Z]-\d{4}\/\d{2}\/\d{2}-\d{4})*)$

this is input validation on a text field. 

[Chris-D]

Sorry my bad, for some reason I'd read your original post as a text label. 

Please see my shortened version though, it's not good to duplicate the whole regex, and you shouldn't need the ^ and $ because it won't match a partial string anyway. 

[KDAI]

you mean this 

([A-Z]{3}-[A-Z]-\d{4}\/\d{2}\/\d{2}-\d{4}(,\s)*)+

it is not case sensitive, is it? does it allow multiple entries with same pattern text separated by ,  it's a text field 255 character long.