Simple Task of Passing a Double Quote to a String Functoid

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This is probably not limited to just double quotes but what seemed to be a simple thing gave me quite a few head-scratching minutes yesterday. 

The task was straightforward.  Customer has a double quote as part of a data string inside of a XML element.  For example: 

<attributeData>data"withdoublequote</attributeData>

The mapping logic required us to output the location of the double quote within the data string.  OK, no problem.  We would use the String Find functoid for this. 

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Unfortunately, when we used the double quote character as 2nd parameter to the functoid, we got an error when testing map:

'userCSharp:StringFind(string(attributeData/text()) , """)' is an invalid XPath expression. This is an unclosed string.

OK, so maybe I needed to use an escape sequence with the double quote character.  For the next 15 minutes, I tried different combinations, including &QUOT; and \”.  None of them worked.

Of course, we could go with the old stand-by, a Script Functoid, with the following inline C#:

public int findQuote(string str)
{
    return (str.IndexOf("\"") + 1);
}

That worked fine but not as easy to maintain and re-use.  In the end, the combination that worked involved using an ASCII to Character Conversion functoid and the String Lookup functoid.  For the ASCII to Character functoid, I used the ASCII value of 34 for the double quote character.  I then connected the output to the String Lookup functoid as 2nd parameter and got the correct position.  Just a simple trick and I think we can find use with other “special” characters as well.

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