Microsoft KB Archive/187318

= ACC97: How to Programmatically Create, Search, Replace, and Modify Code =

Article ID: 187318

Article Last Modified on 1/23/2007

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APPLIES TO


 * Microsoft Access 97 Standard Edition

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This article was previously published under Q187318



Moderate: Requires basic macro, coding, and interoperability skills.



SUMMARY
This article describes and gives you examples of how to programmatically create, search, replace, and modify Visual Basic for Applications code within Microsoft Access 97.

One of the most common uses for code that itself writes code is a wizard. Wizards can be used to offer a variety of solutions that do not require the user to understand, or to have access to, product-development features. For example, a wizard can be used to create custom toolbars and menu bars that meet specific user requirements.



MORE INFORMATION
Determining what code to write based on your users' requirements will be left up to you, the application designer. This article will concentrate on taking the desired code and creating a new subroutine in a new module. It will then go on to demonstrate how to manipulate the code that has just been created. Microsoft provides programming examples for illustration only, without warranty either expressed or implied. This includes, but is not limited to, the implied warranties of merchantability or fitness for a particular purpose. This article assumes that you are familiar with the programming language that is being demonstrated and with the tools that are used to create and to debug procedures. Microsoft support engineers can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific requirements. How to Create a Subroutine in Code --

This example creates a new module, inserts the code for a working subroutine, and then saves, closes, and renames the module.

The code in this example inserts the following subroutine in a module called Create Code:

Sub TestOpenDatabase Dim DB As Database Set DB = CurrentDb MsgBox "The Database " & DB.Name & " opened successfully!" DB.Close End Sub

1. Create a new module and name it "Create Code."

2. In the Create Code module, insert the following lines of code:

Option Compare Database Option Explicit Dim MyModule As Module

Sub CreateCode

Dim strIndent As String, strText As String

' Create 4 spaces for code indent. strIndent = "   "

' Build a string variable with the code to be written ' to the new module. strText = "Sub TestOpenDatabase" & vbCrLf strText = strText & strIndent & "Dim DB As Database" & vbCrLf strText = strText & strIndent & "Set DB = CurrentDB" & vbCrLf strText = strText & strIndent & "MsgBox ""The Database "" & " & _ "DB.Name & " strText = strText & strIndent & strIndent & """ opened " & _ "successfully!""" & vbCrLf strText = strText & strIndent & "DB.Close" & vbCrLf strText = strText & "End Sub"

' Create a new Module. Application.RunCommand acCmdNewObjectModule

' Set MyModule to be the new Module Object. Set MyModule = Application.Modules(Application.CurrentObjectName)

' Insert the code string into the new module. MyModule.InsertText strText

' Save, close, and rename the new Module as "Created Code." DoCmd.Save acModule, MyModule DoCmd.Close acModule, MyModule, acSaveYes DoCmd.Rename "Created Code", acModule, MyModule

End Sub

3. With the pointer anywhere within the CreateCode subroutine, press F5    to run the code.

4. To see the TestOpenDatabase subroutine just created, open the Created Code module.

5. On the Tools Menu, click References, ensure that the Microsoft DAO 3.5 Object Library check box is selected, and then click OK.

6. Run the TestOpenDatabase subroutine.

NOTE: You cannot have multiple modules or subroutines with the same name. Before you run the code in this example a second time, delete the module Create Code.

How to Search for a Code String in a Module ---

This example uses the Find method to locate a string in a module.

Because the Find method is not aware of where any subroutine starts or ends, and because there may be multiple copies of the string you are searching for in the module, you must take care in selecting the correct string. Once the Find method locates the string, it returns the string's line number within the module.

If you wanted to search for a string within a specific subroutine within a module, you could:

A. Use the Find method to locate and save the line number for the first instance of the name of a specific subroutine.

B. Use the Find method to locate and save the line number of the first instance of the string "End Sub" starting at the line number captured in step A by using Find's startline argument.

C. Use the Find method to locate and save the line number of the string you are searching for within the desired subroutine by     specifying the startline from step and the endline from step B by using Find's startline and endline arguments.

In the Find method, the target, startline, startcolumn, endline, and endcolumn arguments are not optional and are updated to the matching string values when Find locates the string. For more information, please see Microsoft Access Help for additional Find method arguments.

In this example, the code searches the module created in the previous example for the string "DB.Close" and inserts the line of code, "Set DB = Nothing" on the following line. It will then save and close the Created Code module.

7. Open the Create Code module and insert the following lines after the code created in the previous example:

Sub SearchCode Dim StartLine As Long, StartColumn As Long Dim EndLine As Long, EndColumn As Long

' Open the Module you want to modify. DoCmd.OpenModule "Created Code"

' Set the Created Code Modules as the Object. Set MyModule = Application.Modules("Created Code")

' Search for string "DB.Close". If MyModule.Find("DB.Close", StartLine, StartColumn, _         EndLine, EndColumn) Then

' If string is found, insert new line of code using the same ' column indent. MyModule.InsertLines StartLine + 1, _ String(StartColumn - 1, " ") & "Set DB = Nothing" Else MsgBox "Text not found." End If

' Save and close the module. DoCmd.Save acModule, MyModule DoCmd.Close acModule, MyModule, acSaveYes

End Sub

8. With the pointer anywhere within the SearchCode subroutine, press F5    to run the code.

9. To see the TestOpenDatabase subroutine just created, open the Created Code module.

10. Run the subroutine TestOpenDatabase.

How to Replace a Line of Code in a Module -

This example uses the Find method to locate the string "Set DB =" and replaces the entire line of code with the following two lines:

"Set DB = DBEngine.OpenDatabase("C:\Program Files\Microsoft Office\" & _      "Office\Samples\Solutions.mdb")"

This example requires that the Solutions.mdb database is in the location specified in the preceding line. If this is not the case, modify the example below to point to a valid database path and file.

11. Open the Create Code module and insert the following lines after the code created in the previous example:

Sub ReplaceCode Dim StartLine As Long, StartColumn As Long Dim EndLine As Long, EndColumn As Long

' Open the Module you want to modify. DoCmd.OpenModule "Created Code"

' Set the Created Code Modules as the Object. Set MyModule = Application.Modules("Created Code")

' Search for string "Set DB =". If MyModule.Find("Set DB =", StartLine, StartColumn, EndLine, _          EndColumn) Then

' If string is found, insert new line of code using the same ' column indent. MyModule.ReplaceLine StartLine, String(StartColumn - 1, " ") & _ "Set DB = DBEngine.OpenDatabase(""C:\Program Files\" & _            "Microsoft Office\"" & _" _             & vbCrLf & "        ""Office\Samples\Solutions.mdb"")"

Else MsgBox "Text not found." End If

' Save and close the module. DoCmd.Save acModule, MyModule DoCmd.Close acModule, MyModule, acSaveYes

End Sub

12. With the pointer anywhere within the ReplaceCode subroutine, press F5     to run the code.

13. To see the TestOpenDatabase subroutine just created, open the Created Code module.

14. Run the TestOpenDatabase subroutine.

How to Modify a Line of Code in a Module

This example uses the Find method to locate the string "Solutions.mdb" and to replace it with "Northwind.mdb".

To accomplish this, the code has to disassemble the located line of text, remove the old string, and reconstruct the line with the new string. As before, it will save and close the module after making the changes.

This example requires that the Solutions.mdb and Northwind.mdb databases are in the location specified in the preceding example. If this is not the case, modify the example below to point to valid database paths and files.

15. Open the Create Code module and insert the following lines after the code created in the previous example:

Sub ModifyCode Dim StartLine As Long, StartColumn As Long Dim EndLine As Long, EndColumn As Long Dim strLine As String, strNewLine As String Dim intChr As Integer, intBefore As Integer, intAfter As Integer Dim strLeft As String, strRight As String Dim strSearchText As String, strNewText

' The string you are searching for is: strSearchText = "Solutions.mdb"

' The replacement string is: strNewText = "Northwind.mdb"

' Open the Module you want to modify. DoCmd.OpenModule "Created Code"

' Set the Created Code Modules as the Object. Set MyModule = Application.Modules("Created Code")

' Search for string. If MyModule.Find(strSearchText, StartLine, StartColumn, EndLine, _           EndColumn) Then

' Store text of line containing string. strLine = MyModule.Lines(StartLine, Abs(EndLine - StartLine) + 1)

' Determine length of line. intChr = Len(strLine)

' Determine number of characters preceding search text. intBefore = StartColumn - 1

' Determine number of characters following search text. intAfter = intChr - CInt(EndColumn - 1)

' Store characters to left of search text. strLeft = Left$(strLine, intBefore)

' Store characters to right of search text. strRight = Right$(strLine, intAfter)

' Construct string with replacement text. strNewLine = strLeft & strNewText & strRight

' Replace the original line. MyModule.ReplaceLine StartLine, strNewLine

Else MsgBox "Text not found." End If

' Save and close the module. DoCmd.Save acModule, MyModule DoCmd.Close acModule, MyModule, acSaveYes

End Sub

16. With the pointer anywhere within the ModifyCode subroutine, press F5     to run the code.

17. To see the TestOpenDatabase subroutine just created, open the Created Code module.

18. Run the subroutine TestOpenDatabase.

