Figure 1 - The Results of a Mad Libs Children's Tale.
Introduction.
When I was taking my much needed vacation with my girlfriend, I found a Brookstone game that brought back childhood camp memories of one my favorite belly-laughing pasttimes, MadLIBS. I still get a kick out of the game after all these years and decided to put together a version for the web. For those who are unfamiliar with the game, it goes something like this. You are prompted for a word by another person (or in this case a computer) in a grammar category. For example you may be asked for a noun or verb or name. You simply name anything in that particular category and it is recorded inside the story in a blanked out word space. You will continue to be prompted for a word fitting a particular grammar until all spots are filled. Then the resulting story is read. As you might imagine, the story takes on an almost mad construction as you have blindly seeded the story with substituted irrelevant words.
MadLibs.NET.
My version of mad libs utilizes a text file that is a template for the story. All information for the game is contained in this file. The file consists of two types of placeholders. One place holder is bracketed with < > . These brackets contain the grammar prompt for all the unfilled spots (e.g. <plural noun>). The other place holder is a set of square brackets [] containing a number (e.g. [0]) . This is a new feature I added to the game to allow the user to repeat a chosen bracketed <> word in another part of the story. The number in the square brackets refers to the order of the <> grammar word. Below is the MadLibs text file for the three little pigs:
Listing 1 - Mad Libs Template File.
Once upon a time there were three little <animal>s. They each lived in three houses. One made of <plural noun>, one made of <plural noun> and one made of <plural noun>. One day the <adjective> [0]s were sitting in their houses, when along came a big <adjective> <animal>. He huffed and he <verb - past tense> and he blew down the house made of [1]. The [0] was so <emotion> that he yelled <exclamation> and ran to the house made of [2]. The [6] <verb - past tense> to the house made of [2] and blew that house to <place>. Both [0]s <verb-past tense> and ran to the house made of [3]. The [6] followed the [0]s to the house made of [3]. He huffed and he puffed, but he could not seem to make the house <action verb>. So the [6] gave up and ran to <place>. The [0]s were very <adjective>.
The MadLib.NET game will continue to prompt the user with each grammar only in the <> brackets. When the programming engine reaches the end of the template, the story is displayed. Word needed for the [] square brackets are automatically substituted by the computer based on the sequence of the <> fields.
Design.
The design of the MadLibs game consists of a web page and a parser. The web page displays all the grammar prompts and the final story. The parser does all the parsing of the template file shown in Listing 1.
Figure 2 - MadLibs.NET Game Reverse Engineered with WithClass UML Tool.
Getting the template file.
Initially, the template file is read into the session and the first prompt is read in from the template and placed in the grammar prompt label. Also we keep a pointer in the session pointing to the last position of the <field> in the template that we read into the prompt.
Listing 2 - Initial reading of the template.
' open a new excel spreadsheet
If Me.IsPostBack Then
Else
' get the madlib template and store it in the session
Dim libText As String = ReadMadLibFromFile("MadFile.txt")
Session("Counter") = 0
' get the first label and place it in the grammar prompt
Dim parser As MadLibParser = New MadLibParser
Dim nextIndex As Integer = 0
Dim grammar As String = parser.ParseNext(0, libText, nextIndex)
Session("NextIndex") = nextIndex
lblMadQuestion.Text = String.Format("{0}: Enter a {1}.", 1, grammar)
End If
After each subsequent push of the button, we parse the next piece of grammar out of the template in the post back and assign the label text. If the end of the template is reached in the post back, we display the final story as shown in Listing 3.
Listing 3 - Reading in grammar after the post back.
If Me.IsPostBack Then
Dim counter As Integer = CInt(Session("Counter")) ' get the current counter, that counts the template field
counter += 1
' get the next grammar field
Dim parser As MadLibParser = New MadLibParser
Dim index As Integer = CInt(Session("NextIndex"))
Dim nextIndex As Integer = index
Dim madText As String = CStr(Session("MadLibForm"))
Dim grammar As String = parser.ParseNext(index, madText, nextIndex)
If nextIndex = -1 Then ' we have reached the end of the template, display the story
RecordNextWord() ' make sure we get the last entered word and put it into the session
Dim story As String = parser.ConstructStory(madText, Session)
txtStory.Text = story
Button1.Enabled = False
Else ' set the prompt for the next grammar field
Session("NextIndex") = nextIndex
lblMadQuestion.Text = String.Format("{0}: Enter a {1}.", counter + 1, grammar)End If
Else
' see listing 2
End If
The button event handler saves the word that the player entered into the Session State. Here we increment a count on each grammar field, and use this to make a unique index into the session state table as shown in listing 4.
Listing 4 - Recording the player's entered word.
Private Sub RecordNextWord()
Dim count As Integer = CInt(Session("Counter"))
Session("Entry" & count.ToString()) = txtGrammarEntry.Text
count += 1
Session("Counter") = count ' store it back in the session
End Sub
Private
Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs)
' store the next entry into the session
RecordNextWord()
End Sub
After all words are entered, the story is constructed from the template. The program goes back through all the players words recorded in the session and places them consecutively inside the template in the appropriate places. All construction is performed in the ConstructStory method of the MadLibParser class. The ConstructStory method first goes through <> fields and replaces them one after another with the player's word entries. It then finds each square bracket field, looks at the number contained in them, and places the appropriate player entry corresponding to the sequence in which the player entered the word. For example, if the square brackets contain "[0]", the program will replace this field with the first entry the player entered in the game.
Listing 5 - Constructing the story from the player words and the madlib template.
Public Function ConstructStory(ByVal madlibFile As String, ByVal session As HttpSessionState) As String
Dim story As String = ""
Dim count As Integer = 0
Dim nextIndex As Integer = 0
Dim index As Integer = 0
' loop through all player entries until there are no more entries
Do While Not session("Entry" & count.ToString()) Is Nothing
' replace the template with the next player entry
madlibFile = ReplaceNext(madlibFile, CStr(session("Entry" & count.ToString())), "<", ">")
count += 1
Loop
' replace square brackets as well
' loop through all square brackets, and replace with the player word
' corresponding to the particular sequence number contained in the brackets
Do While madlibFile.IndexOf("[") >= 0
' parse out sequence number from square brackets
Dim bracketNumber As String = GetNextNumber(madlibFile)
replace template String bracket field with player entry corresponding to the sequence madlibFile = ReplaceNext(madlibFile, CStr(session("Entry" & bracketNumber)), "[", "]")
Loop
Return madlibFile
End Function
Conclusion.
MadLIBS has given me hours of fun as a kid and still makes me chuckle when I read the wacky stories constructed from the game. It's my pleasure to pass on some of that wackiness to you as you stretch your creativity in this entertaining game of words now living on the Web courtesy of C# and .NET.
NOTE: THIS ARTICLE IS CONVERTED FROM C# TO VB.NET USING A CONVERSION TOOL. ORIGINAL ARTICLE CAN BE FOUND ON C# CORNER (WWW.C-SHARPCORNER.COM).