ReportMagic

[While:]NEW

Loops while a condition is true.

Purpose

Use the [While:] / [EndWhile:] macros to repeat a section of the input template while a condition evaluates to true. This is useful for paginated API calls or other scenarios where the iteration count is not known upfront.

Compatibility

The macro can be used in all input document types and in Report Studio.

Usage

The [Break:] and [Continue:] macros can also be used with the [While:] / [EndWhile:] macros, to provide more control over your macro execution. The condition is re-evaluated at the end of each iteration. Variables updated inside the body will affect the next condition check. When nesting [While:] macros, use explicit 'storeAs' names for each loop to avoid counter variable collisions.

Parameters (15)

Grouped View

Mandatory (1)

Parameter	Type	Purpose	Options	Default
condition	String	The loop condition. Must evaluate to true or false. The condition is re-evaluated each iteration with current variable values. Uses the same syntax as the [If:] macro condition parameter.	N/A	N/A

Behaviour (7)

Parameter	Type	Presence	Purpose	Options	Default
errorOnOverflow	Boolean	Optional	Should NCalc expression evaluation throw error on Overflow	true false	true
if	String	Optional	The condition that must be true in order for the macro to be executed/evaluated. Must either evaluate to true or false, for example: "3+5=8" or "contains('abcd', 'z').	N/A	true
ifNoIterations	String	Optional	Text to output if the condition is false on the very first evaluation (zero iterations).	N/A	N/A
maxIterations	Int32	Optional	The maximum number of iterations permitted (1-10000). Defaults to 10000. Use this to prevent accidental infinite loops during development.	From 1 to 10000	10000
mode	MacroMode	Optional	The mode in which variables are stored. In the legacy mode (default for Schedules), the variable created is a string and formatted. In the normal mode (default for Report Studio), the output variable is stored as a strongly-typed theObject, e.g. an Int32 or a List etc., rather than a formatted string.	Legacy Normal	Legacy
obfuscation	ObfuscationType	Optional	Obfuscation type. Use obfuscation to write reports where sensitive data is hidden. When used, ReportMagic guarantees that the same input string will map to the same output string for the whole of the report (but the next time the report runs, it will most likely map to a different value). If you use obfuscation, the property in your macro will not show up and instead, you will see a fake item of the obfuscation type chosen.	None UkTown DeviceName Company IpAddress PrivateIpAddress	None
warning	String	Optional	If specified, adds a warning message for this macro. This is processed as an NCalc, and the warning message will ALWAYS be present and will be the value of the evaluated NCalc expression.	N/A	N/A

Filtering & Sorting (1)

Parameter	Type	Presence	Purpose	Options	Default
condition	String	Mandatory	The loop condition. Must evaluate to true or false. The condition is re-evaluated each iteration with current variable values. Uses the same syntax as the [If:] macro condition parameter.	N/A	N/A

Output (3)

Parameter	Type	Presence	Purpose	Options	Default
failureText	String	Optional	The text to display should the macro fail to execute. Note that a poorly-specified macro (e.g. omitting mandatory parameters) will still result in an error message.	N/A	N/A
failureVariable	String	Optional	The name of a variable to create should the macro fail to execute. The variable will be a text variable, and will contain either the failure text (only if the failureText parameter is set), otherwise it will contain the exception / failure message.	N/A	N/A
storeAs	String	Optional	The name of the 0-based iteration counter variable. Defaults to '_whileIndex'. This variable is only accessible inside the loop body and is removed when the loop ends. When nesting While loops, use unique names to avoid variable collisions.	N/A	_whileIndex

General (4)

Parameter	Type	Presence	Purpose	Options	Default
comment	String	Optional	Add a comment to make your document template more readable. The comment is discarded in the output document.	N/A	N/A
desiredExecutionResult	ExecutionResult	Optional	If specified, asserts the expected execution result of the macro. The macro executes normally; if the actual result matches the desired value, the result is converted to Success. If the actual result does not match, the result is converted to MacroError with a descriptive message. This is primarily used for testing and diagnostic purposes. Valid values are: Unknown, Success, MacroError, WorkerStopped, Running, Warning, NeverRun, Cancelled, Pending, Paused, SystemError, Deferred, Stopped.	Cancelled Deferred MacroError NeverRun Paused Pending Running Stopped Success SystemError Warning WorkerStopped	N/A
expectedType	String	Optional	If specified, asserts the expected output type of the macro result. The macro executes normally; if the actual type does not match, a macro error is generated. Requires 'storeAs', 'storeAsHidden', or 'storeFormattedValueAs' to be set for typed validation. Valid types include CLR names (e.g. Int32, Int64, Single, Double, Boolean, String, JArray, JObject) and C# keyword aliases (e.g. int, long, float, double, bool, string, uint, ulong, short, ushort, byte, sbyte, decimal, char, object). The special value 'Number' matches any numeric type.	N/A	N/A
expectedValue	String	Optional	If specified, asserts the expected output value of the macro result. The macro executes normally; if the actual value does not match, a macro error is generated. When 'storeAs' or 'storeAsHidden' is set, the stored variable value is compared. Otherwise, the document output text is compared.	N/A	N/A

Examples (9)

Example 1

A simple countdown loop:

[String: value=3, =>counter]
[While: condition={counter}>0]
	Counter is: [String: value={counter}]
	[Calculate: value={counter}-1, =>counter]
[EndWhile:]

Outputs: Counter is: 3 Counter is: 2 Counter is: 1

Example 2

Using maxIterations to limit iterations:

[String: value=true, =>keepGoing]
[While: condition='{keepGoing}'=='true', maxIterations=5, storeAs=i]
	Iteration [String: value={i}]
[EndWhile:]

Outputs: Iteration 0 Iteration 1 Iteration 2 Iteration 3 Iteration 4

Example 3

Using ifNoIterations when condition is initially false:

[String: value=false, =>hasData]
[While: condition='{hasData}'=='true', ifNoIterations=No data available.]
	Processing data...
[EndWhile:]

Outputs: No data available.

Example 4

Nested While loops with explicit counter names:

[String: value=2, =>outerCount]
[While: condition={outerCount}>0, storeAs=outerIndex]
	Outer [String: value={outerIndex}]:
	[String: value=2, =>innerCount]
	[While: condition={innerCount}>0, storeAs=innerIndex]
		Inner [String: value={innerIndex}]
	[Calculate: value={innerCount}-1, =>innerCount]
	[EndWhile:]
	[Calculate: value={outerCount}-1, =>outerCount]
[EndWhile:]

Example 5

Using [Break:] to exit the loop early:

[String: value=1, =>n]
[While: condition={n}>0, storeAs=i]
	[If: condition={i}>=3][Break:][EndIf:]
	Item [String: value={i}]
	[Calculate: value={n}+1, =>n]
[EndWhile:]

Outputs: Item 0 Item 1 Item 2

Example 6

Using [Break:] with a countdown:

[String: value=10, =>counter]
[While: condition={counter}>0]
	[Calculate: value={counter}-1, =>counter]
	[If: condition={counter}=3][Break:][EndIf:]
	Value [String: value={counter}]
[EndWhile:]

Outputs: Value 9 Value 8 Value 7 Value 6 Value 5 Value 4

Example 7

Using [Continue:] to skip an iteration:

[String: value=5, =>remaining]
[While: condition={remaining}>0]
	[Calculate: value={remaining}-1, =>remaining]
	[If: condition={remaining}=2][Continue:][EndIf:]
	Value [String: value={remaining}]
[EndWhile:]

Outputs: Value 4 Value 3 Value 1 Value 0

Example 8

Using [Continue:] to skip even numbers:

[String: value=6, =>counter]
[While: condition={counter}>0]
	[Calculate: value={counter}-1, =>counter]
	[Calculate: value={counter}%2, =>isOdd]
	[If: condition={isOdd}=0][Continue:][EndIf:]
	Value [String: value={counter}]
[EndWhile:]

Outputs: Value 5 Value 3 Value 1

Example 9

Accumulating results using [=:] shorthand. The [=:] syntax is shorthand for [Calculate:] and in this case stores integers rather than strings. Variables created inside the loop persist between iterations (unlike the storeAs counter which is cleaned up when the loop ends):

[=: 3, =>outer]
[=: 0, =>total]
[While: condition=`outer > 0`]
	[=: `outer`, =>inner]
	[While: condition=`inner > 0`]
		[=: `total + 1`, =>total]
		[=: `inner - 1`, =>inner]
	[EndWhile:]
	[=: `outer - 1`, =>outer]
[EndWhile:]
Total: [=: total]

Outputs: Total: 6