SharePoint desiner do not allow character { and , together in regular expressoin

Question

I am using a regular expression for email validation and to limit the number of character in SharePoint edit form (data form webpart)

<asp:TextBox runat="server" id="ff58{$Pos}" ControlMode="Edit" FieldName="Email" text="{@FileLeafRef}" __designer:bind="{ddwrt:DataBind('u',concat('ff58',$Pos),'Text','TextChanged','ID',ddwrt:EscapeDelims(string(@ID)),'@FileLeafRef')}" />

<SharePoint:InputFormRegularExpressionValidator ID="Validator" runat="server" Display="Dynamic" SetFocusOnError="true"
  ControlToValidate="ff58{$Pos}"
  ValidationExpression="^[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,4}$"
  ErrorMessage="Enter a valid email address." />

In validationExpression, it does not allow me to use '{' and it thinks it is a Xpath expression. If I am not using '{' in expression it works fine.

In Design view of form, it shows an error :

Failed setting processor stylesheet : 0x80004005 : Expected token '}' found ','. ^[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2-->,<--4}$"

Also, I want to limit the number of characters to 90 in another field and found this expression - /^[a-zA-Z]{1,90}$/ Is there any regular expression that I can use to limit the number of character validation which does not have { and, for it? or any way to use { and, in SharePoint form

Answer 1

Put "{" in a workflow variable and try to use that workflow variable in your statement.

Answer 2

Try this.

[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?

or

^([0-9a-zA-Z]([-.\w]*[0-9a-zA-Z])*@([0-9a-zA-Z][-\w]*[0-9a-zA-Z]\.)+[a-zA-Z]{2,9})$

or

^(?!\.)("([^"\r\\]|\\["\r\\])*"|([-a-z0-9!#$%&'*+/=?^_`{|}~] |(?@[a-z0-9][\w\.-]*[a-z0-9]\.[a-z][a-z\.]*[a-z]$