BizBert - Understanding the BizTalk Mapper: Part 5

Tuesday, February 12, 2008

Understanding the BizTalk Mapper: Part 5 - Logical Functoids

Whenever I've looked at the XSLT generated by a map I've always been confused by the amount of inline C# generated by these functoids.
After the String Functoids I'd say that these are the next most widely used and yet all but one of them has an XSLT v1.0 equivalent!
The code emitted for "Logical Equal" always makes me laugh – 12 lines of C# code can be replaced by... (wait for it)... one "=" symbol!

For each functoid I've shown:

Whether XSLT or C# is emitted
Whether an XSLT equivalent exists
The XSLT or C# emitted by the functoid
Where C# is emitted, the equivalent XSLT to achieve the same functionality (in both XSLT v1.0 and v2.0)

Functoids covered in this category:

Equal	Logical Existence
Greater Than	Logical NOT
Greater Than or Equal To	Logical Numeric
IsNil	Logical OR
Less Than	Logical String
Less Than or Equal To	Not Equal
Logical Date	Common Code

Logical Functoids
	Equal
	Generates: C#	Has XSLT Equivalent: in 1.0 and 2.0
	Emitted Code: public bool LogicalEq(string val1, string val2) { bool ret = false; double d1 = 0; double d2 = 0; if (IsNumeric(val1, ref d1) && IsNumeric(val2, ref d2)) { ret = d1 == d2; } else { ret = String.Compare(val1, val2, StringComparison.Ordinal) == 0; } return ret; }
	XSLT 1.0 Equivalent: Use the "=" operator e.g. value = value
	XSLT 2.0 Equivalent: Use the "=" operator e.g. value = value Note: Both the C# version and the XSLT version will perform a case-sensitive comparison.

	Greater Than
	Generates: C#	Has XSLT Equivalent: in 1.0 and 2.0
	Emitted Code: public bool LogicalGt(string val1, string val2) { bool ret = false; double d1 = 0; double d2 = 0; if (IsNumeric(val1, ref d1) && IsNumeric(val2, ref d2)) { ret = d1 > d2; } else { ret = String.Compare(val1, val2, StringComparison.Ordinal) > 0; } return ret; }
	XSLT 1.0 Equivalent: Use the ">" operator e.g. value > value
	XSLT 2.0 Equivalent: Use the ">" operator e.g. value > value

	Greater Than or Equal To
	Generates: C#	Has XSLT Equivalent: in 1.0 and 2.0
	Emitted Code: public bool LogicalGte(string val1, string val2) { bool ret = false; double d1 = 0; double d2 = 0; if (IsNumeric(val1, ref d1) && IsNumeric(val2, ref d2)) { ret = d1 >= d2; } else { ret = String.Compare(val1, val2, StringComparison.Ordinal) >= 0; } return ret; }
	XSLT 1.0 Equivalent: Use the ">=" operator e.g. value >= value
	XSLT 2.0 Equivalent: Use the ">=" operator e.g. value >= value

	IsNil
	Generates: XSLT	Has XSLT Equivalent: N/A
	Emitted Code: string(node/@xsi:nil) = 'true'

	Less Than
	Generates: C#	Has XSLT Equivalent: in 1.0 and 2.0
	Emitted Code: public bool LogicalLt(string val1, string val2) { bool ret = false; double d1 = 0; double d2 = 0; if (IsNumeric(val1, ref d1) && IsNumeric(val2, ref d2)) { ret = d1 < d2; } else { ret = String.Compare(val1, val2, StringComparison.Ordinal) < 0; } return ret; }
	XSLT 1.0 Equivalent: Use the "<" operator e.g. value < value
	XSLT 2.0 Equivalent: Use the "<" operator e.g. value < value

	Less Than or Equal To
	Generates: C#	Has XSLT Equivalent: in 1.0 and 2.0
	Emitted Code: public bool LogicalLte(string val1, string val2) { bool ret = false; double d1 = 0; double d2 = 0; if (IsNumeric(val1, ref d1) && IsNumeric(val2, ref d2)) { ret = d1 <= d2; } else { ret = String.Compare(val1, val2, StringComparison.Ordinal) <= 0; } return ret; }
	XSLT 1.0 Equivalent: Use the "<=" operator e.g. value <= value
	XSLT 2.0 Equivalent: Use the "<=" operator e.g. value <= value

	Logical AND
	Generates: C#	Has XSLT Equivalent: in 1.0 and 2.0
	Emitted Code: public bool LogicalAnd(string param0, string param1) { return ValToBool(param0) && ValToBool(param1); return false; }
	XSLT 1.0 Equivalent: Use the "and" operator e.g. expression and expression
	XSLT 2.0 Equivalent: Use the "and" operator e.g. expression and expression

	Logical Date
	Generates: C#	Has XSLT Equivalent: No
	Emitted Code: public bool LogicalIsDate(string val) { return IsDate(val); }
	XSLT 1.0 Equivalent: (none)
	XSLT 2.0 Equivalent: (none) Note: an XPath expression could be created using the dateTime function, but would require parsing out separate date/time portions. There are other implementations available on the internet, but none of them are trivial. XPath 1.0 has no native DateTime functionality built in.

	Logical Existence
	Generates: C#	Has XSLT Equivalent: in 1.0 and 2.0
	Emitted Code: public bool LogicalExistence(bool val) { return val; } Note: The above method may seem a bit strange, but it makes sense if you understand that you test for existence of a node in XSLT by using the boolean() function, and passing a node (or any sort of value). The XSLT generated by the Logical Existence functoid wraps the boolean() function round the value passed to the LogicalExistence method like this: userC#:LogicalExistence(boolean(@name)) (where @name was an attribute that we connected to the Logical Existence functoid).
	XSLT 1.0 Equivalent: boolean(node)
	XSLT 2.0 Equivalent: boolean(node)

	Logical NOT
	Generates: C#	Has XSLT Equivalent: in 1.0 and 2.0
	Emitted Code: public bool LogicalNot(string val) { return !ValToBool(val); }
	XSLT 1.0 Equivalent: not(expression)
	XSLT 2.0 Equivalent: not(expression)

	Logical Numeric
	Generates: C#	Has XSLT Equivalent: No
	Emitted Code: public bool LogicalIsNumeric(string val) { return IsNumeric(val); }
	XSLT 1.0 Equivalent: (none)
	XSLT 2.0 Equivalent: (none) Note: You can achieve this through use of a statement such as: string(number(value)) != 'NaN' Or in XPath 2.0 using a statement such as: value castable as xs:decimal

	Logical OR
	Generates: C#	Has XSLT Equivalent: in 1.0 and 2.0
	Emitted Code: Note: there will be one overload per unique number of parameters. Here we show an example with two input parameters. public bool LogicalOr(string param0, string param1) { return ValToBool(param0) \|\| ValToBool(param1); return false; }
	XSLT 1.0 Equivalent: Use the "or" operator e.g. ((expression or expression) or expression)
	XSLT 2.0 Equivalent: Use the "or" operator e.g. ((expression or expression) or expression)

	Logical String
	Generates: C#	Has XSLT Equivalent: No
	Emitted Code: public bool LogicalIsString(string val) { return (val != null && val != ""); }
	XSLT 1.0 Equivalent: (none)
	XSLT 2.0 Equivalent: (none) Note: the same thing can be achieved with an XPath expression.

	Not Equal
	Generates: C#	Has XSLT Equivalent: in 1.0 and 2.0
	Emitted Code: public bool LogicalNe(string val1, string val2) { bool ret = false; double d1 = 0; double d2 = 0; if (IsNumeric(val1, ref d1) && IsNumeric(val2, ref d2)) { ret = d1 != d2; } else { ret = String.Compare(val1, val2, StringComparison.Ordinal) != 0; } return ret; }
	XSLT 1.0 Equivalent: Use the "!=" operator e.g. (value != value)
	XSLT 2.0 Equivalent: Use the "!=" operator e.g. (value != value)

	Common Code (this is common code used by all the logical functoids)
	public bool IsNumeric(string val) { if (val == null) { return false; } double d = 0; return Double.TryParse(val, System.Globalization.NumberStyles.AllowThousands \| System.Globalization.NumberStyles.Float, System.Globalization.CultureInfo.InvariantCulture, out d); } public bool IsNumeric(string val, ref double d) { if (val == null) { return false; } return Double.TryParse(val, System.Globalization.NumberStyles.AllowThousands \| System.Globalization.NumberStyles.Float, System.Globalization.CultureInfo.InvariantCulture, out d); } public bool IsDate(string val) { bool retval = true; try { DateTime dt = Convert.ToDateTime(val, System.Globalization.CultureInfo.InvariantCulture); } catch (Exception) { retval = false; } return retval; } public bool ValToBool(string val) { if (val != null) { if (string.Compare(val, bool.TrueString, StringComparison.OrdinalIgnoreCase) == 0) { return true; } if (string.Compare(val, bool.FalseString, StringComparison.OrdinalIgnoreCase) == 0) { return false; } val = val.Trim(); if (string.Compare(val, bool.TrueString, StringComparison.OrdinalIgnoreCase) == 0) { return true; } if (string.Compare(val, bool.FalseString, StringComparison.OrdinalIgnoreCase) == 0) { return false; } double d = 0; if (IsNumeric(val, ref d)) { return (d > 0); } } return false; }

Tuesday, February 12, 2008 3:16:22 PM (GMT Standard Time, UTC+00:00)

Friday, July 25, 2008 3:18:54 PM (GMT Standard Time, UTC+00:00)

I attempted to create a custom functoid that began with a test for the logical existence of the node; and thought that using the C# for Logical Existence would work. However, using the emitted code as in the Logical Existence example, just doesn't work. Is there any change to the code that would make it work in a custom functoid?

John | lingenfjAT NOSPAMhotmail dot com

Comments are closed.