Microsoft KB Archive/171072

= ACC97: No Error When AddFromFile Creates Duplicate Procedure =

Article ID: 171072

Article Last Modified on 1/20/2007

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APPLIES TO


 * Microsoft Access 97 Standard Edition

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This article was previously published under Q171072



Advanced: Requires expert coding, interoperability, and multiuser skills.



SYMPTOMS
The AddFromFile method does not generate an error when it adds a duplicate procedure to a module.



CAUSE
When the AddFromFile method inserts a procedure into a module, Visual Basic for Applications tries to compile all code in the target module first, and then inserts the procedure if successful.

If you use the AddFromFile method multiple times to insert the same procedure into the same target module, Visual Basic for Applications does not detect a compile error until the third attempt. On the first attempt, Visual Basic for Applications successfully compiles the code, and then inserts the procedure from the text file. On the second attempt, Visual Basic for Applications successfully compiles the code in the target module, which now includes one instance of the procedure from the text file; it then inserts a second copy of the procedure from the text file. On the third attempt, Visual Basic for Applications detects a compile error because there are two instances of the same procedure in the target module.



RESOLUTION
To prevent the AddFromFile method from inserting a duplicate procedure, use the Find method of the Module object to determine if the procedure already exists in the module. To do so, follow these steps:

 Repeat steps 1 through 4 from the "Steps to Reproduce Behavior" section later in this article.  Type the following procedure: Function ImportProc(vbProcName As String) Dim mdl As Module Dim vbLineStop As Long

Set mdl = Modules(0) vbLineStop = mdl.CountOfLines If Not mdl.Find(vbProcName, 1, 1, vbLineStop, 1, False) Then mdl.AddFromFile "C:\My Documents\Test.txt" Else MsgBox "'" & vbProcName & "' already exists in module." End If    End Function  To test this function, type the following line in the Debug window, and then press ENTER:

?ImportProc("Sub AddFromFileTest")

Note that the AddFromFileTest procedure is successfully inserted into the module.  Repeat step 3 to run the procedure again.

Note that the procedure is not inserted into the module, and that you receive the message:       'Sub AddFromFileTest' already exists in module. 

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STATUS
This behavior is by design.

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Steps to Reproduce Behavior
  Using Notepad or another text editor, create a new text file, and add the following text to the text file: Sub AddFromFileTest MsgBox "Hello" End Sub </li> Save and close the text file as C:\My Documents\Test.txt.</li> Start Microsoft Access and open the sample database Northwind.mdb.</li>  Create a module and type the following line in the Declarations section if it is not already there: <pre class="fixed_text">     Option Explicit </li>  Type the following procedure: Function ImportProc Dim mdl As Module Set mdl = Modules(0) mdl.AddFromFile "C:\My Documents\Test.txt" End Function </li> On the Debug menu, click Compile And Save All Modules. When prompted to save the module, type ImportTest and then click OK.</li> Type the following line in the Debug window, and then press ENTER:

?ImportProc

Note that the AddFromFileTest procedure is successfully added to the module.</li> Repeat step 7 to run the ImportProc procedure again.

Note that a second copy of the AddFromFileTest procedure is successfully added to the module, and no error is generated.</li> Repeat step 7 to run the ImportProc procedure a third time.

Note that you receive the message:

Compile Error:

Ambiguous name detected: AddFromFileTest

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