Page Comparison

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TRY <statement> CATCH <statement> |

THROW <expression> |

FOREACH <variablename> IN <expression> <statement> |

BREAK |

TRACE <expression> |

GLOBAL <variablename> [ = <expression> ]

<expression> :== <literal>  |

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<binary_operator> :== one of the following operators

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Comments

Comments may be added anywhere in within a formula body using C/C++ style comment notations

VAR @A = 3  //Everything after the two slashes on this line is considered a comment and is not executed
RETURN /*everything between the slash-stars is a comment and not executed*/ "Hello World"
 

Execution

Each statement within a formula is executed until a RETURN statement is encountered.  The expression supplied to the first executed RETURN statement is the result of the formula.  If no RETURN statement is executed, the result of the formula is NULL.  Each statement type is described below:

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IF @A = 0 THEN
   THROW "Unexpected value"
ELSE
   RETURN @A
 

FOREACH <variable> IN <expression> <statement>

Iterates through an array and executes a statement for each item in the array

For example:

VAR @CountNoIncome = 0
FOREACH @Student in [Students] BEGIN
	IF GetProperty(@Student, 'NoIncome') = True
   		SET @CountNoIncome = @CountNoIncome + 1
END
RETURN @CountNoIncome
 

BREAK

Breaks out of the current innermost WHILE or FOREACH loop.   

For example:

VAR @NoIncomeExists = FALSE
FOREACH @Student in [Students] BEGIN
	IF GetProperty(@Student, "NoIncome") = True BEGIN
   		SET @NoIncomeExists = TRUE
		BREAK	//break out of FOREACH and stop looking at the rest of the students
	END
END
IF @NoIncomeExists BEGIN
END
 

TRACE <expression>

Writes the value of <expression> to the trace log.  This is useful for debugging a formula.  When using the 'Test' button to test a formula, the trace log is displayed along with the results.  Trace events are logged to log4net as DEBUG events for all formula evaluations, whether test or production.

For example:

VAR @NoIncomeExists = FALSE
FOREACH @Student in [Students] BEGIN
	TRACE Format("Checking student {0} for NoIncome flag", GetProperty(@Student, "Fullname"))
	IF GetProperty(@Student, "NoIncome") = True
   		SET @NoIncomeExists = TRUE
END

RETURN @NoIncomeExists
 

GLOBAL <variablename> [ = <expression> ]

Declares a global variable and optionally initializes it to a value.  Global variable persist their values within the same formula body over multiple records.  They are not shared between different formulas.  The initial value is only used to initialize the global variable.  It does not reset the value every time the statement executes.  Use SET to change or reset the value of a global variable.

For example (running summary operations):

GLOBAL @RowCount = 0 //This does not get reset to 0 every time the formula executes, it only initializes the value to 0 the first time
SET @RowCount = @RowCount + 1
RETURN @RowCount //returns the row number of the record within an export

Or (accessing previous records):

GLOBAL @PreviousStudent = NULL
VAR @Result
IF @PreviousStudent = NULL
	SET @Result = NULL
ELSE
	SET @Result = GetProperty(@PreviousStudent, "Fullname")
SET @PreviousStudent = CurrentRecord()  //CurrentRecord() takes the current field values and places them in a object-value result with properties matching the field names
RETURN @Result	//returns the Fullname field value of the previous student record