AMPscript - check string structure

Question

I am trying to set an AMPscript function, that would check it the user provides a proper email name, in a proper format. If a user provides it in a wrong format, an error should appear.

For an error I will use "RaiseError" function, however, I don't know how to check if the structure of the email name string is correct.

The email name should be in the following structure: "xxxxx xxxxx - xxxx xxxx xxxx" - so the first part of the string should be separated by a dash from the second part of the string.

Which function would check if the user provides proper structure of email name?

I have already a function that catches for me the first part of the string (@sub_name):

var @index, @sub_name

Set @index = IndexOf(emailname_,' -')

set @sub_name = Substring(emailname_,1,Subtract(@index,1))    

Answer 1

Normally you would cover these aspects with RegExMatch. But your structure is totally unprecise. You need to exactly know how your valid strings look like. You can also see a sample of RegExMatch functions in an answer i have posted.

To get the stuff in front of your - i would use this. [But then there can only be one - in the whole email address and only once]. If fixed numbers of X then:

%%[
var @emailstring
var @subname1,@subname2,@subname3,@subname4,@subname5
var @valid

set @emailstring = 'Wonder fully-Emai name this'
set @subname1 = RegExMatch(@emailstring,'^(.{5})\s(.{5})-(.{4})\s(.{4})\s(.{4})$',1)
set @subname2 = RegExMatch(@emailstring,'^(.{5})\s(.{5})-(.{4})\s(.{4})\s(.{4})$',2)
set @subname3 = RegExMatch(@emailstring,'^(.{5})\s(.{5})-(.{4})\s(.{4})\s(.{4})$',3)
set @subname4 = RegExMatch(@emailstring,'^(.{5})\s(.{5})-(.{4})\s(.{4})\s(.{4})$',4)
set @subname5 = RegExMatch(@emailstring,'^(.{5})\s(.{5})-(.{4})\s(.{4})\s(.{4})$',5)

set @valid = 'false'
if(NOT Empty(@subname1) and NOT Empty(@subname2) and NOT Empty(@subname3) and NOT Empty(@subname4) and NOT Empty(@subname5)) then
set @valid = 'true'
endif
]%%

%%=v(@valid)=%%<br>

Output then would be

true

not 100% sure if the times{4} parameter work in this, you could change a (.{5}) to (.....)

Answer 2

I came up with a ready solution:

%%[
var @sourceString, @regEx1 
set @sourceString = emailname_
set @regEx1 = ' - '

var @result2
set @result2 = RegExMatch(@sourceString, @regEx1, 0, 'IgnoreCase', 'Multiline')
if Length(@result2) > 0 
then 
    set @check = 1 
else 
    set @check = 0 
endif

if 
    @check == 0
then
RaiseError('Please provide email name in the following pattern: Subscription Name - Custom Name.', false)
endif


]%%