Email Address Validation Function

Did some changes in the delivered code. Page fields were hard coded in the delivered code, made it dynamic.

Function validateEmailAddressEntry(&Email_Addr As string, &Page_Field As string)

Local string &Email_After@, &str_Host, &local_part, &Domain_part;
Local number &Loc@, &Loc_dot, &next_dot, &local_LENGTH, &Domain_length, &LOOP;
Local string &ALPHA_STRING = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz.-";
Local string &char_String = "#$%&'*+/=?^_`{|}~";
Local string &NUM_STRING = "1234567890";

&Email_Addr = RTrim(LTrim(&Email_Addr));

If All(&Email_Addr) Then
&Loc@ = Find("@", &Email_Addr);
&Loc_dot = Find(".", &Email_Addr);

&local_part = Substring(&Email_Addr, 1, &Loc@ - 1);
&Domain_part = Substring(&Email_Addr, &Loc@ + 1, Len(&Email_Addr) - &Loc@);
&local_LENGTH = Len(&local_part);
&Domain_length = Len(&Domain_part);
&Email_After@ = Substring(&Email_Addr, &Loc@ + 1, Len(&Email_Addr) - &Loc@);

/* The e-mail address must contain @ and . characters */
If &Loc@ = 0 Or
&Loc_dot = 0 Then
SetCursorPos(%Page, @(&Page_Field));
Error MsgGet(14100, 895, "The e-mail address must contain @ and . characters");
End-If;

/* The e-mail address shall not contain @ or . at the first character. */
If &Loc@ = 1 Or
&Loc_dot = 1 Then
SetCursorPos(%Page, @(&Page_Field));
Error MsgGet(14100, 896, "The e-mail address shall not contain @ or . at the first character.");
End-If;

/* Two at signs (@) are not allowed */
If (Find("@", &Email_After@) > 0) Then
SetCursorPos(%Page, @(&Page_Field));
Error MsgGet(14100, 899, "Two at signs (@) are not allowed");
End-If;

/* The e-mail address shall not contain - as the first character in Domain name. */
If (Find("-", &Email_After@) = 1) Then
SetCursorPos(%Page, @(&Page_Field));
Error MsgGet(14100, 900, "The e-mail address shall not contain - as the first character in Domain name.");
End-If;

/* The e-mail address shall contain atleast one character between @ and . */
If ((Substring(&Email_Addr, &Loc@ - 1, 1) = ".") Or
(Substring(&Email_Addr, &Loc@ + 1, 1) = ".")) Then
SetCursorPos(%Page, @(&Page_Field));
Error MsgGet(14100, 901, "The e-mail address shall contain atleast one character between @ and .");
End-If;

/* The e-mail address shall not contain @ or . at the last character. */
If ((Substring(&Email_Addr, Len(&Email_Addr), 1) = ".") Or
(Substring(&Email_Addr, Len(&Email_Addr), 1) = "@")) Then
SetCursorPos(%Page, @(&Page_Field));
Error MsgGet(14100, 897, "The e-mail address shall not contain @ or . at the last character.");
End-If;

If (&Loc_dot > 1) Then

/* */
&str_Host = Substring(&Email_Addr, &Loc_dot + 1, Len(&Email_Addr) - &Loc_dot);
&next_dot = Find(".", &str_Host);

While &next_dot > 0
If &next_dot = 1 Then
SetCursorPos(%Page, @(&Page_Field));
Error MsgGet(14100, 902, "The e-mail address shall contain atleast one character between . and .");
Break;
Else
&Loc_dot = &next_dot;
&Email_After@ = &str_Host;
&str_Host = Substring(&str_Host, &next_dot + 1, Len(&str_Host) - &next_dot);
&next_dot = Find(".", &str_Host);
End-If;
End-While;

If Len(&str_Host) < 2 Then SetCursorPos(%Page, @(&Page_Field)); Error MsgGet(14100, 903, "The e-mail address should contain atleast two characters after last ."); End-If; End-If; /* Validate that the local part consists of the ascii characters are described above for local part */ &LOOP = 1; While &LOOP <= &local_LENGTH /* check for alpha in the format */ If ((Find(Substring(&local_part, &LOOP, 1), &ALPHA_STRING) = 0) And (Find(Substring(&local_part, &LOOP, 1), &NUM_STRING) = 0) And (Find(Substring(&local_part, &LOOP, 1), &char_String) = 0)) Then SetCursorPos(%Page, @(&Page_Field)); Warning MsgGet(14100, 904, "Invalid character found in local part of email address."); Break; End-If; &LOOP = &LOOP + 1; End-While; /* Validate that domain name consists letters, digits and hyphens separated by dots */ &LOOP = 1; While &LOOP <= &Domain_length /* check for alpha in the format */ If ((Find(Substring(&Domain_part, &LOOP, 1), &ALPHA_STRING) = 0) And (Find(Substring(&Domain_part, &LOOP, 1), &NUM_STRING) = 0)) Then Warning MsgGet(14100, 905, "Invalid character found in domain part of email address."); Break; End-If; &LOOP = &LOOP + 1; End-While; /* Validate that the local part consists of at least 1 character before the @ sign but not more than 64 characters*/ If &local_LENGTH < 1 Or &local_LENGTH > 64 Then
SetCursorPos(%Page, @(&Page_Field));
Warning MsgGet(14100, 894, "Length of Local part of e-mail address before the @ sign must be >=1 and <= 64.");
End-If;

/* Make sure that atleast two characters are present between @ and . */
&Email_After@ = Substring(&Email_Addr, &Loc@ + 1, Len(&Email_Addr) - &Loc@);
&Loc_dot = Find(".", &Email_After@);
If (&Loc_dot = 0) Then
SetCursorPos(%Page, @(&Page_Field));
Error MsgGet(14100, 895, "The e-mail address must contain @ and . characters");

End-If;
End-If;

End-Function;

>> Tino Simon