Microsoft WSH and VBScript Programming for the Absolute Beginner Part 29 pot

260 Developing the Logic for the Main Processing Section The script’s main processing section controls the overall execution of the script. It consists of 10 function calls and two loops: SetVariableDefaults() ProcessScriptIniFile() CollectPlayerInput() For intSetCount = 1 to intNoOfPlays Do Until blnAllNumbersPicked = “True” GetRandomNumber() ProcessRandomNumber() DetermineIfSetIsComplete() Loop BuildDisplayString() ResetVariableDefaults() Next DisplayFinalResults() DisplaySplashScreen() The first loop is controlled by a For statement that is responsible for making sure that the script generates the number of sets of lottery numbers specified by the player. The second loop is controlled by a Do Until and is responsible for making sure that a full count of numbers is generated for each set (or play). Microsoft WSH and VBScript Programming for the Absolute Beginner, Second Edition Building the SetVariableDefaults() Function The SetVariableDefaults() function, shown here, is responsible for establishing default val- ues for a number of variables used by the script. The first two variables are Boolean and are used to determine when a full set of lottery numbers has been generated and when the player has specified a valid number of plays. The second pair of variables is used to store integer data. The first variable is used to keep track of the number of lottery numbers generated for each play. The second variable is used to track the number of sets of lottery numbers as the script is generating them. Function SetVariableDefaults() blnAllNumbersPicked = “False” blnInputValidated = “False” intNumberCount = 0 intNoOfValidPicks = 0 End Function Building the ProcessScriptIniFile() Function The ProcessScriptIniFile() function, shown here, is responsible for reading in script con- figuration settings from the game’s INI file. Because of the unique task assigned to this func- tion, I chose to make it completely self contained. Therefore, it begins by defining its own objects and variables. To make the purpose of each variable clear, I documented each one by adding comments to the right of each variable when defined as well as to key statements throughout the function. Function ProcessScriptIniFile() Dim FsoObject ‘Sets up a reference to the FileSystemObject Dim OpenFile ‘Sets up a reference to the script’s INI file Set FsoObject = WScript.CreateObject(“Scripting.FileSystemObject”) Dim intEquals ‘Used to parse INI file data Dim strKeyName ‘Represents a key in the script’s INI file Dim strSourceFile ‘Specifies the name of the script’s INI file Dim strInput ‘Represents a line in the script’s INI file 261 Chapter 8 • Storing and Retrieving Data 262 strSourceFile = “LuckyLotteryMachine.ini” ‘Identify script’s INI file If (FsoObject.FileExists(strSourceFile)) Then ‘Make sure INI file exists ‘Open for reading Set OpenFile = FsoObject.OpenTextFile(strSourceFile, 1) Do Until Mid(strInput, 1, 15) = “[GameControls]” ‘Find right section strInput = OpenFile.ReadLine ‘Read line from the INI file Loop ‘Read until end of file reached Do Until OpenFile.AtEndOfStream = “True” strInput = OpenFile.ReadLine ‘Read a line from the file If Mid(strInput, 1, 1) = “[“ Then Exit do ‘If executed, new sections have been found End If If Len(strInput) <> 0 Then ‘Executes if a blank line is not found intEquals = Instr(strInput, “=”) ‘Locate the equals character strKeyName = Mid(strInput, 1, intEquals - 1) ‘Set key value Select Case strKeyName ‘Match up key value to script settings Case “Greeting” strTitleBarMsg = Mid(strInput, intEquals + 1, Len(strInput)) Case “DisplayFormat” strDisplayType = Mid(strInput, intEquals + 1, Len(strInput)) Case “NoOfPicks” intNoOfPicksToSelect = Cint(Mid(strInput, intEquals + 1, _ Len(strInput))) Case “RangeOfNumbers” intRangeOfNumbers = Cint(Mid(strInput, intEquals + 1, _ Len(strInput))) Microsoft WSH and VBScript Programming for the Absolute Beginner, Second Edition End Select End If Loop OpenFile.Close()’Close the INI file when done reading it Else MsgBox “The INI file is missing. Unable to execute.” WScript.Quit() End If End Function The function begins by instantiating an instance of the FileSystemObject. It then specifies the location of its INI file. Next, it checks to make sure that the INI file exists and then opens it. The function then reads the INI file until it finds the [GameControls] section. Once found, the function begins reading the rest of the INI file. The function then parses through the key=value pairs and assigns values to matching script variables using a Select Case statement. Building the CollectPlayerInput() Function The CollectPlayerInput() function is responsible for collecting and validating player input. The overall execution of this function is controlled by the following Do While loop, which executes as long as a Boolean variable named blnInputValidated is not equal to True: Function CollectPlayerInput() Do Until blnInputValidated = “True” intNoOfPlays = InputBox(“How many sets of numbers do “ & _ “you want?”, strTitleBarMsg) If IsNumeric(intNoOfPlays) <> True Then MsgBox “Sorry. You must enter a numeric value. Please “ & _ “try again.”, ,strTitleBarMsg Else 263 Chapter 8 • Storing and Retrieving Data 264 If Len(intNoOfPlays) = 0 Then MsgBox “Sorry. You must enter a numeric value. Please “ & _ “try again.”, ,strTitleBarMsg Else If intNoOfPlays = 0 then MsgBox “Sorry. Zero is not a valid selection. Please “ & _ “try again.”, ,strTitleBarMsg Else blnInputValidated = “True” End If End If End If Loop End Function Three validation tests are performed. The first test uses the VBScript IsNumeric() function to ensure that the input is numeric. The second test uses the Len() function to ensure that the player actually typed in input, as opposed to simply clicking on OK or Cancel. The last valida- tion test checks to make sure that the player did not enter a value of zero. If the input pro- vided by the player passes all three of these tests, then a value of True is assigned to blnInputValidated and the function finishes executing. Building the GetRandomNumber() Function The GetRandomNumber() function, shown here, is responsible for retrieving random numbers for the script. It begins with the Randomize statement to ensure that numbers are randomly generated. Next, a random number is generated. The range from which the number is cre- ated is dictated by the value assigned to intRangeOfNumber, which was previously established by retrieving its value from the script’s INI file. Function GetRandomNumber() Randomize intRandomNo = cInt(FormatNumber(Int((intRangeOfNumbers * Rnd) + 1))) End Function Microsoft WSH and VBScript Programming for the Absolute Beginner, Second Edition Building the ProcessRandomNumber() Function The ProcessRandomNumber() function, shown here, is responsible for ensuring that the same lottery number is not picked twice for a given play or set. It accomplishes this by establish- ing an array named aintLotteryArray. The array is configured to handle up to 11 entries, based on the assumption that this is large enough to handle any amount of lottery numbers a given lottery game might require. Function ProcessRandomNumber() Select Case intRandomNo Case aintLotteryArray(0) Case aintLotteryArray(1) Case aintLotteryArray(2) Case aintLotteryArray(3) Case aintLotteryArray(4) Case aintLotteryArray(5) Case aintLotteryArray(6) Case aintLotteryArray(7) Case aintLotteryArray(8) Case aintLotteryArray(9) Case aintLotteryArray(10) Case Else strLotteryList = strLotteryList & “ “ & intRandomNo & vbTab intNoOfValidPicks = intNoOfValidPicks + 1 aintLotteryArray(intNumberCount) = intRandomNo intNumberCount = intNumberCount + 1 End Select End Function This function begins by comparing the value of the last lottery number that was generated to the numbers stored in the array. The first time through, there won’t be any lottery numbers stored in the array yet. As a result, the lottery number is stored as the first entry in the array. Also, the lottery number is added to a string that is stored in a variable named strLotteryList, which is used elsewhere in the script. Finally, the total number of valid lottery numbers is tracked by adding 1 to intNoOfValidPicks each time a unique lottery number is generated. 265 Chapter 8 • Storing and Retrieving Data 266 Each time this function is called, it checks to see whether the most recently generated random number matches any of the numbers already stored in the array. If it does, nothing happens; otherwise, that number is added to the array. Building the DetermineIfSetIsComplete() Function The DetermineIfSetIsComplete() function, shown here, compares the value stored in intNoOfValidPicks to the value stored in intNoOfPicksToSelect to determine whether a com- plete set of lottery numbers has been generated. If a complete set has been generated, then DetermineIfSetIsComplete() sets the value assigned to blnAllNumbersPicked equal to True. Otherwise, the value assigned to this variable remains set equal to False. Function DetermineIfSetIsComplete If intNoOfValidPicks = intNoOfPicksToSelect Then blnAllNumbersPicked = “True” End If End Function Building the BuildDisplayString() Function The BuildDisplayString() function, shown here, takes the string stored in the strLotteryList variable (which is created by the ProcessRandomNumber() function) and uses it to build a larger string made up of all the sets of lottery numbers generated by the game. This string is later used to display the game’s result to the player. To make the displayed output more attractive, this function uses the vbTab constant to organize output into a multi-column format. Function BuildDisplayString() strLotteryList = intSetCount & “)” & vbTab & strLotteryList strDisplayString = strDisplayString & strLotteryList & _ vbCrLf & vbCrLf & vbCrLf End Function Building the ResetVariableDefaults() Function The ResetVariableDefaults() function, shown here, is used to reset variable values back to their initial default settings after a full set of lottery numbers has been generated. This readies the script to begin generating additional sets of numbers. Microsoft WSH and VBScript Programming for the Absolute Beginner, Second Edition Function ResetVariableDefaults() blnAllNumbersPicked = “False” intNoOfValidPicks = 0 intNumberCount = 0 strLotteryList = “” End Function Building the DisplayFinalResults() Function The DisplayFinalResults() function, shown here, is responsible for displaying all the sets of lottery numbers that are generated. It displays this information in one of two formats based on the value assigned to strDisplayType, which is a variable whose value was set earlier in the script by retrieving its value from the script’s INI file. If strDisplayType is equal to Full, then the function displays information regarding the number of lottery numbers that was generated per set as well as the total number of sets that were created, followed by the num- bers that made up each set. However, if the value assigned to strDisplayType is equal to any- thing other than Full, then only the sets of lottery numbers are displayed. Function DisplayFinalResults() If strDisplayType = “Full” Then MsgBox vbCrLf & _ “L U C K Y L O T T E R Y N U M B E R P I C K E R” & _ vbCrLf & vbCrLf & _ “——————————————————————————-” & _ “——————————————-” & vbCrLf & vbCrLf & _ “Number of plays: “ & intNoOfPlays & vbCrLf &vbCrLf & _ “Number of picks per play: “ & intNoOfPicksToSelect & _ vbCrLf & vbCrLf & _ “——————————————————————————-” & _ “——————————————-” & vbCrLf & vbCrLf & vbCrLf & _ “Your lottery numbers are: “ & vbCrLf & vbCrLf & vbCrLf & _ strDisplayString, , strTitleBarMsg Else 267 Chapter 8 • Storing and Retrieving Data 268 MsgBox vbCrLf & _ “L U C K Y L O T T E R Y N U M B E R P I C K E R” & _ vbCrLf & vbCrLf & _ “——————————————————————————-” & _ “——————————————-” & vbCrLf & vbCrLf & _ “Your lottery numbers are: “ & vbCrLf & vbCrLf & vbCrLf & _ strDisplayString, , strTitleBarMsg End If End Function Building the DisplaySplashScreen() Function This last function in the script displays the game’s splash screen, providing information about the game and its creator as well as an invitation for the player to return and play again another time. Function DisplaySplashScreen() MsgBox “Thank you for using the Lucky Lottery Number Picker “ & _ “© Jerry Ford 2004.” & vbCrLf & vbCrLf & “Please play again “ & _ “soon!”, 4144, strTitleBarMsg WScript.Quit() End Function The last statement in the function terminates the script’s execution using the WScript Quit() method. The Final Result That’s it. You’re all done. Your fully assembled script should look like this: ‘************************************************************************* ‘Script Name: LuckyLotteryNumberPicker.vbs ‘Author: Jerry Ford ‘Created: 11/08/04 ‘Description: This script randomly picks lottery numbers. ‘************************************************************************* Microsoft WSH and VBScript Programming for the Absolute Beginner, Second Edition ‘Initialization Section Option Explicit Dim aintLotteryArray(10) ‘Stores randomly generated lottery numbers Dim blnAllNumbersPicked ‘Determines when a set of #s has been created Dim blnInputValidated ‘Set to True when the player enters a valid number Dim intNumberCount ‘Tracks the number of picks for a given play Dim intNoOfValidPicks ‘Tracks the # of valid selections for a given set Dim intNoOfPlays ‘Determines the # of sets of lottery #s to create Dim intSetCount ‘Used to track how many sets have been generated Dim intRandomNo ‘Used to store randomly generated lottery #s Dim intNoOfPicksToSelect ‘Specifies how many #s to generate for each set Dim intRangeOfNumbers ‘Specifies range to use when generating random #s Dim strLotteryList ‘Displays a string showing 1 set of lottery #s Dim strDisplayString ‘Used to display the list of selected lottery #s Dim strDisplayType ‘Specifies whether to show full or summary data Dim strTitleBarMsg ‘Specifies title bar message in pop-up dialogs ‘Main Processing Section ————————————————————————- SetVariableDefaults() ProcessScriptIniFile() CollectPlayerInput() For intSetCount = 1 to intNoOfPlays Do Until blnAllNumbersPicked = “True” GetRandomNumber() 269 Chapter 8 • Storing and Retrieving Data . from the script’s INI file. Function GetRandomNumber() Randomize intRandomNo = cInt(FormatNumber(Int((intRangeOfNumbers * Rnd) + 1))) End Function Microsoft WSH and VBScript Programming for the Absolute. controlled by a Do Until and is responsible for making sure that a full count of numbers is generated for each set (or play). Microsoft WSH and VBScript Programming for the Absolute Beginner, Second. _ Len(strInput))) Microsoft WSH and VBScript Programming for the Absolute Beginner, Second Edition End Select End If Loop OpenFile.Close()’Close the INI file when done reading it Else MsgBox The INI file