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I want to use the same regex for server side as client side but when I convert it over to JS it always returns false. I think the string literal is causing the issue but I am not seeing where. I found this but still can't figure it out: Lost in translation - C# regex to JavaScript regex

Here is my server-side code:

public static string EmailRegex = @"^[a-zA-Z0-9_\\.-]+@([a-zA-Z0-9-]+\\.)+[a-zA-Z]{2,6}$";

Here is the razor:

<input type="text" id="email" name="email" data-regex="@Model.EmailRegex" />

Here is the rendered HTML:

<input type="text" id="email" name="email" data-regex="^[a-zA-Z0-9_\\.-]+@([a-zA-Z0-9-]+\\.)+[a-zA-Z]{2,6}$">

Here is the JS code which gets called on $("#email").keyup():

function validateElementRegex(element) {
    var regex = $(element).data("regex");
    var value = $(element).val();
    return validateRegex(value, regex);
}

function validateRegex(value, regex) {
    if (typeof(value) === "undefined" || typeof(regex) === "undefined") {
        return false;
    }
    var regexType = typeof(regex);        // string e.g. "^[a-zA-Z0-9_\\.-]+@([a-zA-Z0-9-]+\\.)+[a-zA-Z]{2,6}$"
    var pattern = new RegExp(regex, "i"); // tried with and without "i" - ignoreCase
    var patternType = typeof(pattern);    // object
    var result = pattern.test(value);     // always false

    return result;
}

Thanks

Community
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Antoni
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1 Answers1

2

Oh well you have an extra backslash in your regex:

^[a-zA-Z0-9_\\.-]+@([a-zA-Z0-9-]+\\.)+[a-zA-Z]{2,6}$

The above regex matches email@myeamil\.com

but it does not match email@myeamil.com

It should be:

^[a-zA-Z0-9_\\.-]+@([a-zA-Z0-9-]+\.)+[a-zA-Z]{2,6}$
Bryan Elliott
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