Function: Validate the Contents of an Input Object

[Lorne]

This function can be used in AutoPlay Media Studio 5.0 Professional to perform some simple data validation on an input object. You can use it to test the object's contents for the following criteria:

• minimum length (at least x characters)
• maximum length (no more than x characters)
• numeric characters only (no letters allowed)

This function also demonstrates a naming technique that lets you create "categorized" functions that resemble the built-in actions in AutoPlay. You simply create a table and then define the function as an item in that table. (This is in fact how the built-in actions are done, although with some extra behind-the-scenes autocomplete and quickhelp magic.)

-- create the InputTest table if it doesn't already exist
if not InputTest then InputTest = {}; end

--[[	
Function:	InputTest.Validate
Purpose:	Perform some simple validation on an input object.
Arguments:	(string) ObjectName - The name of the object you want to test.
          	(number) nMinChars - The minimum number of characters required.
          	(number) nMaxChars - The maximum number of characters allowed. (nil for no limit)
          	(boolean) bNumbersOnly - true if only numeric characters are allowed.
Returns:	true if the edit field is meets the criteria, false if it doesn't.
--]]
function InputTest.Validate(ObjectName, nMinChars, nMaxChars, bNumbersOnly)
	local strText = Input.GetText(ObjectName);
	local nLen = String.Length(strText);
	
	if(nLen < nMinChars) then
		return false;
	end
	
	if( (nMaxChars ~= nil) and (nLen > nMaxChars)) then
		return false;
	end

	if(bNumbersOnly) then
		-- does the string consist only of valid numeric characters?
		if(String.TrimRight(strText, "1234567890-.") ~= "") then
			return false;
		end
	end

	return true;
end

Here is a short example demonstrating how you might call the function. Insert this example code in the On Click event for an object on a page that has an input object named "Input1" on it.

if(InputTest.Validate("Input1", 3, 5, true)) then
	Dialog.Message("HK-47 says:","Observation: Well done, Master! Your response passes my expert validation protocols.");
else
	Dialog.Message("HK-47 says:","Warning: Incorrect response.\r\n\r\nResolution: Enter a number between 3 and 5 digits long.");
end

Note that the function's second and third parameters are optional...you can test for only a minimum of 3 characters (with no maximum and alphanumeric characters okay) with the following call:

if(InputTest.Validate("Input1", 3)) then
	-- test passed
end

Requirements:

Note: this function will only work with AutoPlay Media Studio 5.0 Professional Edition, since the Standard Edition does not have an input object.

[Lorne]

Here is a modified version of the InputTest.Validate function that let's you specify what characters are valid, to make the function more flexible:

-- create the InputTest table if it doesn't already exist
if not InputTest then InputTest = {}; end

--[[	
Function:	InputTest.Validate
Purpose:	Perform some simple validation on an input object.
Arguments:	(string) ObjectName - The name of the object you want to test.
          	(number) nMinChars - The minimum number of characters required.
          	(number) nMaxChars - The maximum number of characters allowed. (nil for no limit)
          	(string) strValidChars - a string containing the list of valid characters, or nil if no character checking should be performed.
Returns:	true if the edit field is meets the criteria, false if it doesn't.
--]]
function InputTest.Validate(ObjectName, nMinChars, nMaxChars, strValidChars)
	local strText = Input.GetText(ObjectName);
	local nLen = String.Length(strText);
	
	if(nLen < nMinChars) then
		return false;
	end
	
	if( (nMaxChars ~= nil) and (nLen > nMaxChars)) then
		return false;
	end

	if(strValidChars) then
		if(String.TrimRight(strText, strValidChars) ~= "") then
			return false;
		end
	end

	return true;
end
_strNumericChars = "1234567890-.";

Instead of a boolean switch to test for numeric characters, you can now pass a list of characters that are valid. The _strNumericChars variable still makes it easy to test for numeric characters. Here's the same example as before, modified to use the new function:

if(InputTest.Validate("Input1", 3, 5, _strNumericChars)) then
	Dialog.Message("HK-47 says:","Observation: Well done, Master! Your response passes my expert validation protocols.");
else
	Dialog.Message("HK-47 says:","Warning: Incorrect response.\r\n\r\nResolution: Enter a number between 3 and 5 digits long.");
end

This version of the InputTest.Validate function would work well with a function that determines the appropriate list of characters for the user's locale, e.g. whether the decimal place should be a comma or a period:

--[[	
Function:	InputTest.GetLocalizedNumericChars
Purpose:	Get a string containing the valid numeric characters for the current locale settings.
Arguments:	None.
Returns:	A string containing the valid numeric characters for the current locale settings.
--]]
function InputTest.GetLocalizedNumericChars()
	local strNumericChars = Registry.GetValue(HKEY_CURRENT_USER,"Control Panel\\International","sMonDecimalSep")
	                      ..Registry.GetValue(HKEY_CURRENT_USER,"Control Panel\\International","sPositiveSign")
	                      ..Registry.GetValue(HKEY_CURRENT_USER,"Control Panel\\International","sNegativeSign")
	                      ..Registry.GetValue(HKEY_CURRENT_USER,"Control Panel\\International","sNativeDigits");
	
	return strNumericChars;
end

Here is the same example rewritten to use this function:

if(InputTest.Validate("Input1", 3, 5, InputTest.GetLocalizedNumericChars())) then
	Dialog.Message("HK-47 says:","Observation: Well done, Master! Your response passes my expert validation protocols.");
else
	Dialog.Message("HK-47 says:","Warning: Incorrect response.\r\n\r\nResolution: Enter a number between 3 and 5 digits long.");
end

[csd214]

Lorne,
Your first function was great, but now even GREATER!

To take advantage of the function InputTest.GetLocalizedNumericChars() I had to add the line
_strNumericChars = InputTest.GetLocalizedNumericChars();
AFTER the function’s end statement.

The code lines in “Globals” OUTSIDE function-end paragraph seem to be executed like “PRE.On Preload” statements?

In a previous post Lorne’s two great input validation scripts you said that the sign has to be the first character. I removed the "sPositiveSign" and "sNegativeSign" from function InputTest.GetLocalizedNumericChars() and created another function InputTest.GetLocalizedNumericSigns() with these registry values to assign value to _strNumericSigns. At start of function InputTest.Validate(ObjectName, nMinChars, nMaxChars, strValidChars) I added:

if String.Find(_strNumericSigns, String.Left(strText, 1), 1, false) > 0 then
    	-- first character is the sign, remove it
    	strText = String.Mid(strText, 2, nLen - 1);
end

International users (with comma as decimappoint) has to remember: If the input value is to be used in a math operation, the comma has to be replaced by the dot.

NumericValue1 = String.Replace(Input.GetText("Input1"), ",", ".", false);