c# - Encoding XPath Expressions with both single and double quotes

Question

XPath (v1) contains no way to encode expressions.

If you only have single OR double quotes then you can use expressions such as

//review[@name="Bob's Pizza"]
//review[@name='"Pizza" Pam']

But if you have BOTH e.g [Fred's "Fancy Pizza"] then you have to use something like this Escaping Strings in XPath (C++) to generate

//review[@name=Concat("Fred's ",'"Fancy Pizza"')]

Anyone have a function in c# to do this?

Some links that are close

• Use the MVP.XML library and XPathVariable (a very good solution but a bit heavyweight for my needs).
• Doesn't encode where both " and ' are present
• Adds more arguments to the Concat operation than is necessary e.g. would return //review[@name=concat('Fred', "'", 's ', '"', 'Fancy Pizza', '"', '')]

EDIT: A few answers have suggested escaping ' with ' and " with " but although this makes sense it does not work; try it using the XML fragment:

<review name="Bob's Pizza"/>

and the xpath

//review[@name='Bob's Pizza']

Answer 1

Wow, you all sure are making this complicated. Why not just do this?

public static string XpathExpression(string value)
{
    if (!value.Contains("'"))
        return ''' + value + ''';

    else if (!value.Contains("""))
        return '"' + value + '"';

    else
        return "concat('" + value.Replace("'", "',"'",'") + "')";
}

.NET Fiddle & test