Good Form

If we stopped with only what has been posted in this blog so far, we would have a powerful tool set to create meaningful charts and drill down pivot tables from data residing in just about any database.  It only takes a couple of minutes to replace the SQL statement in Macro1() and to set parameters in a pivot table wrapper or two, at which point, your customers can see the relationships in their data and begin to identify opportunities for improvement. 

Since starting this blog, my team’s customers have received spreadsheets that determine employee’s bonuses, identify underperforming accounts, measure staff efficiencies, respond to external customers’ requests for information, etc., etc., etc.  There’s a lot you can do with what we’ve provided here but there’s more we can do to make our delivered product follow “good form.”

We have been using VBA’s “InputBox” function to ask users which records to pull.  This works as long as there’s only one parameter and as long as your customer readily knows all values for it.  Often, neither of these two situations apply.  Often, transaction dates with employee IDs, or customer IDs, or account numbers, etc. determine which records to retrieve.  For this, we need a good form.  

frmPrompt Dates and IDs

Good forms improve the user’s experience and increase the power of your product by handling multiple parameters and checking those parameters before bothering the server with a meaningless request and frustrating our customers with unsatisfactory results. For the next several posts, we will be looking at two forms, and derivations of one, that address the most common prompts for parameters.

The smaller form, frmPrompt, is the initial form.  By subtracting screen elements and passing parameters, we can customize this form to handle just about any request for data without changes to code; however, occasionally I do modify this form.  In my environment, I often add a group box with radio buttons to select iSeries libraries so the same spreadsheet can be used over different companies sharing the same server.  I suspect most other environments won’t need this capability so to simplify things, I have omitted that feature.  My only reason for mentioning this is to emphasize something I pointed out on the first page of this blog – these techniques are designed for developers.  What you, the developer, brings to these techniques is critical.  Though most of the code is isolated so that changes are often not required, all of the code is provided so you can adapt it to your special requirements without hindrance.  And with that said…  

The larger form, frmSelect_Multiple, supports frmPrompt.  It responds to the ellipse buttons (. . .) and facilitates searching for ID’s, Codes, Accounts, and such.  Since creating this form many years ago, it has never needed modification of any type to accommodate any master file, or code file.  Hopefully, you’ll be as lucky.  But should you have a need, the code is there for you to change.

frmSelect_Multiple

My next post will be a stripped down version of frmPrompt to get you introduced (assuming you haven’t been already) to the art of creating forms in VBA.

Say Goodbye to QueryTables

We started with the QueryTable object in order to ease into this subject.  It’s time to say farewell to QueryTable and fully embrace ADO.  I’m using ADO, not because it’s the best, but because it is compatible with everything my customers have and (I’m guessing) with 98% of all current XL installs, and because the coding for ADO is nearly identical to the older DAO and other newer database access methods available to VBA.  So as technology progresses, our code needn’t change drastically.

We are replacing the QueryTable object with a call to another function that snaps into our code.  The function looks very much like the SQLRead function from the last post.  Here it is:

Function SQLLoad(sSQL As String, _
                 sConnect As String, _
                 sRange As String, _
                 Optional sSheet As String, _
                 Optional sName As String, _
                 Optional iTimeOut As Integer, _
                 Optional bAppend As Boolean) As Boolean

'   SQLLoad:     Loads an XL Range with data from a database table/file

'   Parameters:  sSQL        SQL Select statement
'                sConnect    Connection String
'                sRange      upper left cell address (ex. "A5") to put data
'                sSheet      worksheet to receive data
'                sName       name to give the retuned data
'                iTimeout    milliseconds to wait for a result before quitting
'                bAppend     Set to true to append data to a previous result

'   Example:     bResult =  SQLLoad("Select * From QUSRSYS/QAEZDISK", _
'                                   "DRIVER={iSeries Access ODBC Driver};" & _
'                                   "SYSTEM=10.0.0.3;NAM=1;", _
'                                   "A4","Data","Data",300,False )

'     Date   Init Modification
'   01/01/01 CWH  Initial Programming

    On Error GoTo ErrHandler
    SQLLoad = Failure           'Assume Something went wrong

    Dim cn As ADODB.Connection  'Connection Object
    Dim rs As ADODB.Recordset   'Recordset Object
   
    Dim lRows As Long           'Number of Rows in Range
    Dim lCols As Long           'Number of Columns in Range
    Dim l As Long               'Generic long variable
   
    Settings "Save"             'Save XL Settings
    Settings "Disable"          'Disable screen updates, etc.
   
 '  Print the start time and SQL string in VBA's immediate window
    Debug.Print "Start:", Time, sSQL
   
 '  Clear spreadsheet if this is not appending to existing data
    If Not bAppend Then
        If sSheet > " " Then
            Worksheets(sSheet).Activate
            If ClearAll(sSheet) Then GoTo ErrHandler
        End If
    End If
                    
'   Create Connection and Recordset Objects
    Set cn = New ADODB.Connection
    cn.Properties("Prompt") = adPromptComplete
    cn.Open sConnect, "", ""
    Set rs = New ADODB.Recordset
   
'   Restrict how long the query can run before failing
    If iTimeOut > 0 Then
        cn.CommandTimeout = iTimeOut
    End If
   
'   Get the data from the database
    rs.Open sSQL, cn
      
    With Range(sRange)
        lCols = rs.Fields.Count
'       Add column headings (if not appending)
        If Not bAppend Then
            For l = 0 To lCols - 1
                .Cells(1, l + 1) = rs(l).Name
                .Cells(1, l + 1).Font.Bold = True
            Next l
            l = 2
'       Position to end of data to append to
        Else
            lRows = Range(sName).Rows.Count - 1
        End If
'       Read Recordset and copy to XL
        While Not rs.EOF
            lRows = lRows + .Cells(lRows + 2, 1).CopyFromRecordset(rs, 10000)
            If Not rs.EOF Then lRows = lRows - 1
        Wend
'       Resize columns to fit data
        Cells.EntireColumn.AutoFit
'       Create a name for the data
        If sName > " " Then Names.Add sName, Range(.Cells(1, 1), _
            .Cells(lRows + 1, lCols))
    End With
       
 '  Set column headings to repeat at top of page on printouts
    ActiveSheet.PageSetup.PrintTitleRows = "$" & Range(sRange).Row & _
                                          ":$" & Range(sRange).Row
       
 '  Print the end time in VBA's immediate window
    Debug.Print "End:", Time
   
    SQLLoad = Success

ErrHandler:
   
    If Err.Number <> 0 Or cn.Errors.Count <> 0 Then
        SQLLoad = Failure
        If Err.Number <> 0 Then
            MsgBox "SQLLoad - Error#" & Err.Number & vbCrLf & Err.Description, _
                vbCritical, "Error", Err.HelpFile, Err.HelpContext
        Else
            Dim errLoop As ADODB.Error
            For Each errLoop In cn.Errors
                MsgBox "SQLLoad - Error number: " & errLoop.Number & vbCr & _
                    errLoop.Description, vbCritical, "Error", errLoop.HelpFile, _
                    errLoop.HelpContext
            Next errLoop
        End If
    End If
    On Error Resume Next
    If rs.State > 0 Then rs.Close   'Close Recordset
    If cn.State > 0 Then cn.Close   'Close Connection
    Settings "Restore"              'Restore XL Settings
    On Error GoTo 0
   
End Function 

Here is the modified MACRO1() with the QueryTable replaced.  Note that it looks similar, and cleaner.

Sub Macro1()

    Dim s As String
    Dim sSQL As String
    Dim sConnect As String
  
    s = Trim( _
             InputBox("Enter State Code:" & vbCr & vbCr & _
                 "'%' is a wildcard.  By itself it will retrieve all states. " & _
                 "'N%' will retrieve all states beginning with 'N'" & vbCr & _
                 "'%Y' will retrieve all states ending in 'Y'", _
                 "State Code Prompt", "%") _
            )
   
    If s > "" Then
        sConnect = "Driver={Microsoft Access Driver (*.mdb, *.accdb)};" & _
                   "DBQ=C:\Users\chatmaker\Documents\Northwind 2007.accdb;"
           
        sSQL = "SELECT O.`Order ID`, O.`Customer ID`, " & vbCr & _
               "       O.`Order Date`, C.`First Name`, " & vbCr  & _
               "       O.`Ship State/Province`, D.Quantity, " & vbCr & _
               "       P.`Product Name` " & vbCr & _
               "FROM   Customers C, Orders O, " & vbCr & _
               "       `Order Details` D, Products P " & vbCr & _
               "WHERE  O.`Customer ID` = C.ID " & vbCr & _
               "  AND  O.`Order ID`    = D.`Order ID` " & vbCr & _
               "  AND  D.`Product ID`  = P.ID " & vbCr & _
               "  AND  C.`State/Province` LIKE '" & s & "'"
       
        SQLLoad sSQL, sConnect, "A4", "Data", "Data"
       
        Pivot_Template       
    End If
   
End Sub

How to Copy Code from this Blog to XL

1. Open your XL spreadsheet containing modGeneral.
2. Get to the VBE (Alt-F11)
3. Open modGeneral in the Code Window
4. From this post, select and copy the code
5. Paste into the Code Window (*see next paragraph)
6. Make any corrections to code that didn’t paste correctly
7. From the VBE menu navigate File > Export File…
8. Save modGeneral and remember where you saved it.

Unfortunately, the code won’t paste 100% properly.  You will have to add carriage returns and perhaps fix a few things until your code looks exactly like what you see here.

Using ADO to Read a Database

Up till now, we’ve used XL’s QueryTable object to retrieve records from databases.  This post breaks away from the QueryTable to leverage the power of ADO.  One of the advantages of ADO is that we can create user defined functions to use directly in XL just like any normal XL function.

As before, we will use a VBA function that can be easily snapped into other code.  This function uses an SQL Statement and a Connection String to retrieve data and return it to the calling routine as a simple string.

Because we are using ADO, we need to add the “Microsoft ActiveX  Data Objects x.x Library”  reference (Where the x.x is the lowest version of the library your users are likely to have.  Some of my users still have Office 2003 which works with version 2.6).  To add a reference, load your XL spreadsheet, go to the VBE (Alt-F11), and from the menu take Tools > References.  From the “Available References” list, scroll down until you find the reference we need. Check it then click OK.  That’s all there is to it.  

Here is the code:

Function SQLRead(sSQL As String, sConnect As String, _
                 Optional iTimeOut As Integer, _
                 Optional bDisplayErrors As Boolean, _
                 Optional cn As ADODB.Connection) As String

'   SQLRead:     Returns a database result set as a string

'   Parameters:  sSQL           SQL Select statement
'                sConnect       Connection String
'                iTimeout       Milliseconds to wait for results before error
'                bDisplayErrors Set to False to surpress error displays
'                cn             Connection Object. If sent, sConnect is ignored
'                               Use this to speed up multiple reads

'   Example:     Cell(1,2) =  SQLExec(sSQL, sConnect)

'     Date   Init Modification
'   01/01/01 CWH  Initial Programming

    On Error GoTo ErrHandler
    SQLRead = Failure    'Assume Something went wrong

    Dim cnSent As Boolean
    Dim rs As ADODB.Recordset
   
    Dim s As String
    Dim lCols As Long
    Dim l As Long
   
'   If connection object not sent, create from connection string
    cnSent = True
    If cn Is Nothing Then
        cnSent = False
        Set cn = New ADODB.Connection
        cn.Properties("Prompt") = adPromptComplete
        cn.Open sConnect, "", ""
    End If
    Set rs = New ADODB.Recordset
   
'   Restrict how long the query can run before failing
    If iTimeOut > 0 Then
        cn.CommandTimeout = iTimeOut
    End If
   
'   Get the data from the database
    rs.Open sSQL, cn
      
'   Put results into a comma delimited string
    lCols = rs.Fields.Count
    If Not rs.EOF Then
        rs.MoveFirst
        s = ""
        If Not rs.EOF Then
            For l = 0 To lCols - 1
                s = s & IIf(l > 0, ",", "") & """" & rs(l) & """"
            Next l
        End If
    End If
   
'   Return results
    SQLRead = s
   
ErrHandler:
   
    If Err.Number <> 0 Or cn.Errors.Count <> 0 Then
        SQLRead = Failure
        If Err.Number <> 0 Then
            MsgBox "SQLRead - Error#" & Err.Number & vbCrLf & Err.Description, _
                vbCritical, "Error", Err.HelpFile, Err.HelpContext
        Else
            Dim errLoop As ADODB.Error
            For Each errLoop In cn.Errors
                MsgBox "SQLRead - Error number: " & errLoop.Number & vbCr & _
                    errLoop.Description, vbCritical, "Error", _
                    errLoop.HelpFile, errLoop.HelpContext
            Next errLoop
        End If
    End If
    On Error Resume Next
    If rs.State > 0 Then rs.Close	'Close the record set
'   Close the connection object if created in this routine
    If Not cnSent Then If cn.State > 0 Then cn.Close
    On Error GoTo 0
   
End Function 

To test our function, let’s create an XL User Defined Function (UDF).  The code for our test is shown below.  After adding the code below (with the reference and the function above), go back to XL and put Customer ID “27″ in cell “A4″.  In cell “B4″, enter this formula: “=CustomerName(“A4″).  Our routine will retrieve the customer’s name and display it in cell “B4″. 

Public Function CustomerName(sID As String) As String

'   CustomerName:  Get Customer Name UDF

'   Parameters:    ID     Customer ID

'   Example:       =CustomerName("A4")

'     Date   Init Modification
'   11/10/09 CWH  Initial Programming

    On Error GoTo ErrHandler

    Dim sSQL As String
    Dim sConnect As String

    sSQL = "SELECT  C.`First Name` " & _
           "FROM    Customers C " & _
           "WHERE   C.ID = " & sID
    sConnect = "Driver={Microsoft Access Driver (*.mdb, *.accdb)};" & _
               "DBQ=C:\Users\chatmaker\Documents\Northwind 2007.accdb;"
'   NOTE: For previous versions of Access use:
'   sConnect = "Driver={Microsoft Access Driver (*.mdb)};" & _
'              "DBQ=C:\Users\chatmaker\Documents\Northwind.mdb;"
    CustomerName = Replace(SQLRead(sSQL, sConnect), """", "")

ErrHandler:
   
    If Err.Number <> 0 Then MsgBox _
        "CustomerName- Error#" & Err.Number & vbCrLf & Err.Description, _
        vbCritical, "Error", Err.HelpFile, Err.HelpContext
    On Error GoTo 0

End Function

How to Copy Code from this Blog to XL

1. Open your XL spreadsheet containing modGeneral.
2. Get to the VBE (Alt-F11)
3. Open modGeneral in the Code Window
4. From this post, select and copy the code
5. Paste into the Code Window (*see next paragraph)
6. Make any corrections to code that didn’t paste correctly
7. From the VBE menu navigate File > Export File…
8. Save modGeneral and remember where you saved it.

Unfortunately, the code won’t paste 100% properly.  You will have to add carriage returns and perhaps fix a few things until your code looks exactly like what you see here.

Delivering a Finished Product

Last post I introduced the wrapper for creating PivotTables and PivotCharts.  This wrapper isolates the changes you must make to add PivotTables and PivotCharts to just one routine.  By isolating these changes, your job is simplified and setting up PivotTables and Charts can easily take less than a minute.  All that’s left to do is to add one line to Macro1 to call the wrapper.  Once you add that line, all your user has to do to is click the “easy” button to retrieve their data, see it in a graph they can easily filter, and see it in a PivotTable that automatically provides “drill down” support.  Here is how Macro1 should look.  (*Note: The red line must be changed to where your Northwind database resides).

Sub Macro1()

    Dim s As String

'   Ask user for input parameters   

    s = Trim( _
             InputBox("Enter State Code:" & vbCr & vbCr & _
                 "'%' is a wildcard.  By itself it will retrieve all states. " & _
                 "'N%' will retrieve all states beginning with 'N'" & vbCr & _
                 "'%Y' will retrieve all states ending in 'Y'", _
                 "State Code Prompt", "%") _
            )
   
'   If OK was pressed then process request
    If s > "" Then
       
'       Clear the spreadsheet 
        Cells.Delete
        Cells.ClearContents
       
'       Get the data
        With ActiveSheet.ListObjects.Add( _
                SourceType:=0, _
                Source:=Array( _
                    "ODBC;" & _
                    "DSN=MS Access Database;" & _
                    "DBQ=C:\Users\chatmaker\Documents\Northwind 2007.accdb;"), _
                Destination:=Range("$A$5")).QueryTable
           
            .CommandText = Array( _
                "SELECT O.`Order ID`, O.`Customer ID`, O.`Order Date`, " & _
                       "C.`First Name`, O.`Ship State/Province`, " & _
                       "D.Quantity, P.`Product Name` " & vbCr, _
                "FROM   Customers C, Orders O, " & _
                      "`Order Details` D, Products P " & vbCr, _
                "WHERE  O.`Customer ID` = C.ID " & vbCr & _
                "  AND  O.`Order ID`    = D.`Order ID` " & _
                "  AND  D.`Product ID`  = P.ID " & _
                "  AND  C.`State/Province` LIKE '" & s & "'")
            .RowNumbers = False
            .ListObject.DisplayName = "Data_Data"
            .Refresh BackgroundQuery:=False        
        End With
               
'       Name the data range
        With Range("Data_Data")
            Names.Add "Data", _
                Range(.Cells(0, 1), .Cells(.Rows.Count, .Columns.Count))
            Range(Cells(.Row, 3), _
                  Cells(.Row + .Rows.Count, 3)).NumberFormat = "m/d/yy;@"
        End With
       
'       Add a PivotTable and PivotChart
        Pivot_Template
       
    End If
   
End Sub

1. The user clicks the “easy” button which invokes Macro1()
2. Macro1() gets the user input and retrieves data from the database
3. The data is sent to the XL spreadsheet in tab Data
4. Macro1 calls Pvt_Template
5. Pvt_Template sets the PivotTable values and calls Setup_Pivot
6. Setup_Pivot creates the PivotTable in tab pvtTemplate and returns control to Pvt_Template
7. Pvt_Template calls Setup_PivotChart 
8. Setup_PivotChart creates the PivotChart in tab chtTemplate .  Control passes up the stack to Macro1() which ends

Basic Process

Wrapping things up

Today I’m introducing a “wrapper” for our Pivot Table and Pivot Chart routines.  The wrapper isolates setting unique parameters from the main routine that extracts data.   Though the routine looks lengthy, it contains no logic, only parameters and instructions on how to modify it .  The instructions can be removed and not all of the parameters are required.

In this example, we create a PivotTable and chart results for the top 20 selling products with quantities broken out by state as shown in http://itknowledgeexchange.techtarget.com/beyond-excel/pivots-and-charts/. 

Function Pivot_Template() As Boolean

'   Pivot_Example:  Sample Pivot Table and Pivot Chart wrapper

'   Parameters:     None 

'   Instructions:   Copy this,
'                   Change all instances of "Pivot_Template" to your routine's name
'                   Modify constants
'                   Increase dimensions of arrays if needed to accomodate more than
'                       1 row, column, etc
'                   Set variable values
'                   Delete these instructions from your routine 

'   Example:        Pivot_Template

'     Date   Init Modification
'   01/01/01 CWH  Initial Programming    

    On Error GoTo ErrHandler                  

    Pivot_Template = Failure                  'Assume the Worst

'   NOTE TO PGMR: Modify these constants' values
    Const sWorksheet = "pvtTemplate"          'Name for the PivotTable & Worksheet
    Const sDataRange = "Data"                 'Named range containing raw data
    Const sTitle = "Top 20 Products by State" 'PivotTable's title
    Const sChartType = xlColumnStacked        'Chart type to create (Optional)
'   NOTE TO PGMR: End modification to constants' values       

'   NOTE TO PGMR: Modify array dimensions (usually not required)
'                 0 = the first element so a dimension of 1 means 2 elements
'                 Changes are required ONLY if you want MORE than 1 element
    Dim sPageFields(0) As String              '0=# of Page Fields   (Optional)
    Dim sRowFields(0) As String               '0=# of Row Fields    (Required)
    Dim sColumnFields(0) As String            '0=# of Column Fields (Recommended)
    Dim sDataFields(0, 2) As String           '0=# of Data Field    (Required)
    Dim sMaxFields(0, 2) As String            '0=# of Restrictions  (Optional)
    Dim sSortFields(0, 2) As String           '0=# of Sort fields   (Optional)
'   NOTE TO PGMR: End modifications to array dimensions 

'   NOTE TO PGMR: Set parameter values. Set to "" for optional parameters you
'                 don't want or delete the parameter line from this routine
    sPageFields(0) = "Customer ID"            'Allow filtering entire pivot on this
    sRowFields(0) = "Product Name"            'This field goes down the side
    sColumnFields(0) = "Ship State/Province"  'This field goes across the top
    sDataFields(0, 0) = "Quantity"            'This field goes in the body
    sDataFields(0, 1) = "SUM"                     'Calculation performed
    sDataFields(0, 2) = "SUM Quantity"            'Name for the calculated result
    sMaxFields(0, 0) = "Product Name"         'This field is restricted
    sMaxFields(0, 1) = 20                         'To the top n values
    sMaxFields(0, 2) = "SUM Quantity"             'based on this field's value
    sSortFields(0, 0) = "Product Name"        'This field is sorted
    sSortFields(0, 1) = "Descending"              'in Ascending/Descending order
    sSortFields(0, 2) = "SUM Quantity"            'based on this field's value
'   NOTE TO PGMR: End modification to parameter values 

'   Create the Pivot Table
    Setup_Pivot sWorksheet, sDataRange, sTitle, _
                sPageFields(), sRowFields(), sColumnFields(), sDataFields(), _
                sSortFields(), sMaxFields()

'   Create a chart based on the pivot table (Optional)
    Setup_PivotChart Replace(sWorksheet, "pvt", "cht", 1, 1), _
                             sWorksheet, sChartType, sTitle

    Pivot_Template = Success                  'Successful finish

ErrHandler:
        If Err.Number <> 0 Then MsgBox _
            "Pivot_Template - Error#" & Err.Number & vbCrLf & Err.Description, _
            vbCritical, "Error", Err.HelpFile, Err.HelpContext
        On Error GoTo 0

End Function

How to Copy Code from this Blog to XL

1. Open your XL spreadsheet containing modGeneral.
2. Get to the VBE (Alt-F11)
3. Open modGeneral in the Code Window
4. From this post, select and copy the code
5. Paste into the Code Window (*see next paragraph)
6. Make any corrections to code that didn’t paste correctly
7. From the VBE menu navigate File > Export File…
8. Save modGeneral and remember where you saved it.

Unfortunately, the code won’t paste 100% properly.  You will have to add carriage returns and perhaps fix a few things until your code looks exactly like what you see here.

Building a Library of Routines – Setup_PivotChart

In our last post we added a function that creates Pivot Tables.  Pivot Tables are fantastic for summarizing data and automatically adding “drill down” functionality.  But people usually like to see things graphically.  The creators of XL realized this and provide functions for graphing Pivot Table results.  That’s what this next function does.  It’s purpose is to reduce the many Pivot Chart properties and methods down to just one function and as few parameters as possible to create meangingful and dynamic representations of your data that your customers can change simply by changing filters in the drop downs automatically provided.

Copy this to your modGeneral as before.  In my next post I will show you how to ”snap” these routines into our Northwind data extract to create impactful graphs and dynamic drill downs. 

Function Setup_PivotChart(sChartSheet As String, sWorksheet As String, _
                          lChartType As XlChartType, sTitle As String) As Boolean

'   Setup_PivotChart:Set up a Pivot Table Chart

'   Parameters:
'       sChartSheet  - The chartsheet to be created to contain the chart
'       sWorkSheet   - The worksheet name where the Pivot Table data is
'       sChartType   - The type of chart to created
'   Example:    Setup_PivotChart "chtHrs", "pvtHrs", "BarClustered"

'     Date   Init Modification
'   01/12/06 CWH  Initial Programming
'   05/15/09 CWH  Changed sChartType to lChartType to add flexibility

    On Error GoTo ErrHandler            '
    Setup_PivotChart = Failure          'Assume the Worst
               
    Settings "Save"
    Settings "Disable"
   
'   Dim Statements
    Dim i As Integer
    Dim n As Integer
   
'   Create Chart
    Worksheets(sWorksheet).Activate
    If Not ChartExists(sChartSheet) Then
        Charts.Add
        Charts(ActiveChart.Name).Name = sChartSheet
    End If
   
    Charts(sChartSheet).Activate

    ActiveChart.SetSourceData Source:=Sheets(sWorksheet). _
        Range(Sheets(sWorksheet).PivotTables(1).RowRange.Address)
    ActiveChart.Location WHERE:=xlLocationAsNewSheet
    
'   Plot Area Formatting
    ActiveChart.PlotArea.Fill.OneColorGradient _
        Style:=msoGradientDiagonalUp, Variant:=2, Degree:=1
    ActiveChart.PlotArea.Fill.ForeColor.SchemeColor = 36
   
    ActiveChart.ChartType = lChartType
    'Chart Types - From http://msdn.microsoft.com/en-us/library/bb241008.aspx
    'Name Value Description
    'xl3DArea -4098 3D Area.
    'xl3DAreaStacked 78 3D Stacked Area.
    'xl3DAreaStacked100 79 100% Stacked Area.
    'xl3DBarClustered 60 3D Clustered Bar.
    'xl3DBarStacked 61 3D Stacked Bar.
    'xl3DBarStacked100 62 3D 100% Stacked Bar.
    'xl3DColumn -4100 3D Column.
    'xl3DColumnClustered 54 3D Clustered Column.
    'xl3DColumnStacked 55 3D Stacked Column.
    'xl3DColumnStacked100 56 3D 100% Stacked Column.
    'xl3DLine -4101 3D Line.
    'xl3DPie -4102 3D Pie.
    'xl3DPieExploded 70 Exploded 3D Pie.
    'xlArea 1 Area
    'xlAreaStacked 76 Stacked Area.
    'xlAreaStacked100 77 100% Stacked Area.
    'xlBarClustered 57 Clustered Bar.
    'xlBarOfPie 71 Bar of Pie.
    'xlBarStacked 58 Stacked Bar.
    'xlBarStacked100 59 100% Stacked Bar.
    'xlBubble 15 Bubble.
    'xlBubble3DEffect 87 Bubble with 3D effects.
    'xlColumnClustered 51 Clustered Column.
    'xlColumnStacked 52 Stacked Column.
    'xlColumnStacked100 53 100% Stacked Column.
    'xlConeBarClustered 102 Clustered Cone Bar.
    'xlConeBarStacked 103 Stacked Cone Bar.
    'xlConeBarStacked100 104 100% Stacked Cone Bar.
    'xlConeCol 105 3D Cone Column.
    'xlConeColClustered 99 Clustered Cone Column.
    'xlConeColStacked 100 Stacked Cone Column.
    'xlConeColStacked100 101 100% Stacked Cone Column.
    'xlCylinderBarClustered 95 Clustered Cylinder Bar.
    'xlCylinderBarStacked 96 Stacked Cylinder Bar.
    'xlCylinderBarStacked100 97 100% Stacked Cylinder Bar.
    'xlCylinderCol 98 3D Cylinder Column.
    'xlCylinderColClustered 92 Clustered Cone Column.
    'xlCylinderColStacked 93 Stacked Cone Column.
    'xlCylinderColStacked100 94 100% Stacked Cylinder Column.
    'xlDoughnut -4120 Doughnut.
    'xlDoughnutExploded 80 Exploded Doughnut.
    'xlLine 4 Line.
    'xlLineMarkers 65 Line with Markers.
    'xlLineMarkersStacked 66 Stacked Line with Markers.
    'xlLineMarkersStacked100 67 100% Stacked Line with Markers.
    'xlLineStacked 63 Stacked Line.
    'xlLineStacked100 64 100% Stacked Line.
    'xlPie 5 Pie.
    'xlPieExploded 69 Exploded Pie.
    'xlPieOfPie 68 Pie of Pie.
    'xlPyramidBarClustered 109 Clustered Pyramid Bar.
    'xlPyramidBarStacked 110 Stacked Pyramid Bar.
    'xlPyramidBarStacked100 111 100% Stacked Pyramid Bar.
    'xlPyramidCol 112 3D Pyramid Column.
    'xlPyramidColClustered 106 Clustered Pyramid Column.
    'xlPyramidColStacked 107 Stacked Pyramid Column.
    'xlPyramidColStacked100 108 100% Stacked Pyramid Column.
    'xlRadar -4151 Radar.
    'xlRadarFilled 82 Filled Radar.
    'xlRadarMarkers 81 Radar with Data Markers.
    'xlStockHLC 88 High-Low-Close.
    'xlStockOHLC 89 Open-High-Low-Close.
    'xlStockVHLC 90 Volume-High-Low-Close.
    'xlStockVOHLC 91 Volume-Open-High-Low-Close.
    'xlSurface 83 3D Surface.
    'xlSurfaceTopView 85 Surface (Top View).
    'xlSurfaceTopViewWireframe 86 Surface (Top View wireframe).
    'xlSurfaceWireframe 84 3D Surface (wireframe).
    'xlXYScatter -4169 Scatter.
    'xlXYScatterLines 74 Scatter with Lines.
    'xlXYScatterLinesNoMarkers 75 Scatter with Lines and No Data Markers.
    'xlXYScatterSmooth 72 Scatter with Smoothed Lines.
    'xlXYScatterSmoothNoMarkers 73 Scatter with Smoothed Lines and No Data Markers.
    
'   Series Formatting - Choose Variant 1 for Columns and Area, 2 for Bars
    For i = 1 To ActiveChart.SeriesCollection.Count
        If lChartType = xlPie Or lChartType = xl3DPie _
           Or lChartType = xl3DPieExploded Then
            On Error Resume Next
            For n = 1 To ActiveChart.SeriesCollection(i).Points.Count
                ActiveChart.SeriesCollection(i).Points(n).Fill.ForeColor. _
                    SchemeColor = _
                    Choose((n Mod 10) + 1, 2, 5, 13, 3, 6, 4, 50, 11, 18, 9)
                ActiveChart.ApplyDataLabels
                ActiveChart.SeriesCollection(i).DataLabels.Font.Bold = True
                ActiveChart.SeriesCollection(i).DataLabels.Font.Color = _
                    RGB(255, 255, 255)
                ActiveChart.SeriesCollection(i).DataLabels.Font.Size = 12
                ActiveChart.SeriesCollection(i).DataLabels.NumberFormat = _
                    "#,###.00_);[Red](#,###.00)"
            Next n
            On Error GoTo ErrHandler
        Else
            ActiveChart.SeriesCollection(i).Fill.ForeColor.SchemeColor = _
                Choose((i Mod 10) + 1, 2, 5, 13, 3, 6, 4, 50, 11, 18, 9)
        End If
    Next i
       
    With Charts(sChartSheet)
        .HasTitle = True
        .ChartTitle.Text = sTitle
    End With
   
    Setup_PivotChart = Success           'Successful finish

ErrHandler:
   
    If Err.Number <> 0 Then MsgBox _
        "Setup_PivotChart - Error#" & Err.Number & vbCrLf & Err.Description, _
        vbCritical, "Error", Err.HelpFile, Err.HelpContext
    Settings "Restore"
    On Error GoTo 0

End Function

How to Copy Code from this Blog to XL

1. Open your XL spreadsheet containing modGeneral.
2. Get to the VBE (Alt-F11)
3. Open modGeneral in the Code Window
4. From this post, select and copy the code
5. Paste into the Code Window (*see next paragraph)
6. Make any corrections to code that didn’t paste correctly
7. From the VBE menu navigate File > Export File…
8. Save modGeneral and remember where you saved it.

Unfortunately, the code won’t paste 100% properly.  You will have to add carriage returns and perhaps fix a few things until your code looks exactly like what you see here.

Building a Library of Routines – Setup_Pivot

This next function is the heart and soul of creating Pivot Tables.  It’s purpose is to reduce the many Pivot Table properties and methods down to just one function and as few meaningful parameters as possible to create every Pivot Table my customers have every asked for.  Hopefully, your customers aren’t any more demanding.

Copy this to your modGeneral as before.  We will add one more routine for creating Pivot Charts, and then I will show you how to ”snap” these routines into our Northwind data extract to create impactful graphs and dynamic drill downs. 

Function Setup_Pivot(sWorksheet As String, sDataRange As String, _
                     sTitle As String, sPageFields() As String, _
                     sRowFields() As String, sColumnFields() As String, _
                     sDataFields() As String, sSortFields() As String, _
                     sMaxFields() As String) As Boolean

'   Setup_Pivot:    Set up a Pivot Table Worksheet and Pivot Table

'   Parameters:    
'       sWorkSheet      - The worksheet name where the Pivot Table will be placed
'                         and the Pivot Table name.
'       sDataRange      - The data range (raw data/database extract)
'       sTitle          - A Title to put above the pivot table
'       sRowFields(#)   - Column headers in the data range that will appear
'                         down the left of the pivot table
'       sColumnFields(#)- Column headers in the data range that will appear
'                         across the top of the pivot table
'       sDataFields(#,2)
'                   #,0 = Column headers (field name) in the data range that
'                         will be in the body of the pivot table
'                   #,1 = Operation to be performed on the data (sum,count,etc.)
'                   #,2 = Caption to use for the resulting data field
'       sSortFields(#,2)
'                   #,0 = Row or Column field to sort
'                   #,1 = Ascending or Descending order
'                   #,2 = Data field to use to sort by
'       MaxFields(#,2)
'                   #,0 = Row or Column field to restrict
'                   #,1 = Max Number of entries to display
'                   #,2 = Data field to restrict by
'   Example:
'       Setup_Pivot sWorkSheet, sDataRange, sTitle, _
'                   sPageFields(), sRowFields(), sColumnFields(), sDataFields(), _
'                   sSortFields(), sMaxFields()

'     Date   Init Modification
'   01/12/06 CWH  Initial Programming Copyright 2009 Craig Hatmaker
   
    On Error GoTo ErrHandler            '
    Setup_Pivot = Failure               'Assume the Worst
               
    Settings "Save"                     'Save current settings
    Settings "Disable"                  'Disable events, updating, calculations
   
'   Dim Statements
    Dim i As Integer
       
'   Check for the Pivot Table Worksheet and create it if it doesn't exist
    If Not WorkSheetExists(sWorksheet) Then
        Sheets.Add
        Sheets(ActiveSheet.Name).Name = sWorksheet
    Else
        Worksheets(sWorksheet).Activate
        Cells.Select
        Selection.Clear
    End If

    If PivotTableExists(sWorksheet, sWorksheet) Then
'       Just Refresh the Pivot Table if it already exists
        Worksheets(sWorksheet).PivotTables(sWorksheet).RefreshTable
    Else
'        Create the Pivot Table if it doesnt' exist
         ActiveWorkbook.PivotCaches.Add(SourceType:=xlDatabase, _
                                        SourceData:=sDataRange).CreatePivotTable _
                                        TableDestination:=Range("A4"), _
                                        TableName:=sWorksheet
         With ActiveSheet.PivotTables(sWorksheet)
            .SmallGrid = False
           
'           Add Pivot Table Page Field   
            For i = 0 To UBound(sPageFields())
                If sPageFields(i) <= "" Then Exit For
                With .PivotFields(sPageFields(i))
                   .Orientation = xlPageField
                   .Subtotals = Array( _
                     False, False, False, False, False, False, _
                     False, False, False, False, False, False)
                End With
            Next i

'           Add Pivot Table Row Fields   
            For i = 0 To UBound(sRowFields())
                If sRowFields(i) <= "" Then Exit For
                With .PivotFields(sRowFields(i))
                   .Orientation = xlRowField
                   .Subtotals = Array( _
                     False, False, False, False, False, False, _
                     False, False, False, False, False, False)
                End With
            Next i

'           Add Pivot Table Column Fields   
            For i = 0 To UBound(sColumnFields())
                If sColumnFields(i) <= "" Then Exit For
                With .PivotFields(sColumnFields(i))
                   .Orientation = xlColumnField
                   .Subtotals = Array( _
                     False, False, False, False, False, False, _
                     False, False, False, False, False, False)
                End With
            Next i

'           Add Pivot Table Data Fields, Function & Format   
            For i = 0 To UBound(sDataFields(), 1)
                If sDataFields(i, 0) <= "" Then Exit For
                With .PivotFields(sDataFields(i, 0))
                    .Orientation = xlDataField
                    If sDataFields(i, 1) <= "" Then sDataFields(i, 1) = "Count"
                    Select Case UCase(sDataFields(i, 1))
                        Case Is = "SUM"
                            .Function = xlSum
                        Case Is = "AVERAGE"
                            .Function = xlAverage
                        Case Is = "MAX"
                            .Function = xlMax
                        Case Is = "MIN"
                            .Function = xlMin
                        Case Is = "COUNTNUMS"
                            .Function = xlCountNums
                        Case Is = "PRODUCT"
                            .Function = xlProduct
                        Case Is = "STDEVP"
                            .Function = xlStDevP
                        Case Else
                            .Function = xlCount
                    End Select
                    .NumberFormat = "#,###.00_);[Red](#,###.00)"
                    If sDataFields(i, 2) <= "" Then sDataFields(i, 2) = _
                       sDataFields(i, 1) & " of " & sDataFields(i, 0)
                    .Caption = sDataFields(i, 2)
                End With
            Next i

'           Sort columns and rows   
            For i = 0 To UBound(sSortFields(), 1)
                If sSortFields(i, 0) <= "" Then Exit For
                If sSortFields(i, 1) = "Descending" Then
                    .PivotFields(sSortFields(i, 0)).AutoSort _
                    xlDescending, sSortFields(i, 2)
                Else
                    .PivotFields(sSortFields(i, 0)).AutoSort _
                    xlAscending, sSortFields(i, 2)
                End If
            Next i

'           Restrict to top/bottom entries   
            For i = 0 To UBound(sMaxFields(), 1)
                If sMaxFields(i, 0) <= "" Then Exit For
                If sMaxFields(i, 1) > 0 Then
                    .PivotFields(sMaxFields(i, 0)).AutoShow _
                    xlAutomatic, xlTop, Val(sMaxFields(i, 1)), sMaxFields(i, 2)
                Else
                    .PivotFields(sMaxFields(i, 0)).AutoShow _
                    xlAutomatic, xlBottom, Val(sMaxFields(i, 1)) * -1, _
                        sMaxFields(i, 2)
                End If
            Next i
        End With

 '      Orient datafields in columns         
        If UBound(sDataFields(), 1) > 0 Then
            With ActiveSheet.PivotTables(sWorksheet).DataPivotField
                .Orientation = xlColumnField
                .Position = 1
            End With
        End If

'       Freeze panes on row and column titles                  
        Range(ActiveSheet.PivotTables(sWorksheet).DataBodyRange.Address). _
            Cells(1, 1).Select
        ActiveWindow.FreezePanes = True
   
    End If

'   Add Worksheet Title   
    With Worksheets(sWorksheet)
        .Rows("1:1").MergeCells = False
        Range(.Cells(1, 1), .Cells(1, .PivotTables(sWorksheet).TableRange1. _
            Columns.Count)).Merge
        .Cells(1, 1) = sTitle
        .Cells(1, 1).Font.Bold = True
        .Cells(1, 1).HorizontalAlignment = xlHAlignLeft
    End With
       
    Setup_Pivot = Success               'Successful finish

ErrHandler:
   
    If Err.Number <> 0 Then MsgBox _
        "Setup_Pivot - Error#" & Err.Number & vbCrLf & Err.Description, _
        vbCritical, "Error", Err.HelpFile, Err.HelpContext
    Settings "Restore"                  'Restore active window & settings
    On Error GoTo 0

End Function

How to Copy Code from this Blog to XL

1. Open your XL spreadsheet containing modGeneral.
2. Get to the VBE (Alt-F11)
3. Open modGeneral in the Code Window
4. From this post, select and copy the code
5. Paste into the Code Window (*see next paragraph)
6. Make any corrections to code that didn’t paste correctly
7. From the VBE menu navigate File > Export File…
8. Save modGeneral and remember where you saved it.

Unfortunately, the code won’t paste 100% properly.  You will have to add carriage returns and perhaps fix a few things until your code looks exactly like what you see here.

Building a Library of Routines – Settings

Last post we added some small routines that tell us if various things exist so we can avoid trying to recreate what’s already there.  That avoids errors and speeds things along.  Another speed enhancer for just about any VBA routine is to shut off screen updating and calculations.  And if you ever create a routine that handles worksheet events (and I do), disabling those events while you make changes to worksheets prevents infinite loops and other problems.

The Settings routine handles turning those things off and back on.  Specifically, it is intended to:

1. Save the current ActiveSheet, ScreenUpdating, EnableEvents, and Calculation properties
2. Disable them before processing begins
3. Restore them after processing ends

Three values alert Settings to which of those three functions it’s supposed to perform.  Those values are: “Save”, “Disable”, and “Restore”.  There are two other values Settings responds to.  They are: “Clear” and “Debug” which are intended to facilitate development and debugging.  “Clear” removes any saved settings.  “Debug” displays the current settings in the Immediate Window.

I like to call “Settings” from button handlers, other event handlers, and routines that could potentially be long running and make changes to the screen.  

Below is the code.  To copy this routine:

1. Get to the VBE (Alt-F11)
2. From the VBE menu navigate File > Import File…
3. Load modGeneral (see previous post) 
4. Select and copy the code below
5. Paste into the Code Window  *
6. Make any corrections to code that didn’t paste correctly
7. From the VBE menu navigate File > Export File…
8. Save modGeneral

* Unfortunately, the code won’t paste 100% properly.  You will have to add carriage returns and perhaps fix a few things until your code looks exactly like what you see here.  If someone knows a better method, please let me know so I can improve this blog.  Thanks.

Next Post: Setup_Pivot – a function for creating Pivot Tables from code.

Function Settings(sMode As String) As Boolean

'   Settings:       Saves, sets, and restores current application settings

'   Parameters:     sMode - "Save", "Restore", "Clear", "Disable", "Debug"
'   Example:        bResult = Settings("Disable")

'     Date   Init Modification
'   01/01/01 CWH  Initial Programming Copyright 2009 Craig Hatmaker

    On Error GoTo ErrHandler
    Settings = Failure                  'Assume the worst
   
    Static Setting(999, 4) As Variant  'Limit to 1,000 settings, prevent loops
    Static iLevel As Integer

    Select Case UCase(Trim(sMode))
        Case Is = "SAVE"
            Setting(iLevel, 0) = ActiveSheet.Type
            Setting(iLevel, 1) = ActiveSheet.Name
            Setting(iLevel, 2) = Application.EnableEvents
            Setting(iLevel, 3) = Application.ScreenUpdating
            Setting(iLevel, 4) = Application.Calculation
            iLevel = iLevel + 1
       
        Case Is = "RESTORE"
            If iLevel > 0 Then
                iLevel = iLevel - 1
                If Setting(iLevel, 0) = -4167 Then
                    Worksheets(Setting(iLevel, 1)).Activate
                Else
                    Charts(Setting(iLevel, 1)).Activate
                End If
                Application.EnableEvents = Setting(iLevel, 2)
                Application.ScreenUpdating = Setting(iLevel, 3)
                Application.Calculation = Setting(iLevel, 4)
            End If
      
        Case Is = "CLEAR"
            iLevel = 0
            Application.EnableEvents = True
            Application.ScreenUpdating = True
            Application.Calculation = xlCalculationAutomatic
           
        Case Is = "DISABLE"
            Application.EnableEvents = False
            Application.ScreenUpdating = False
            Application.Calculation = xlCalculationManual
           
        Case Is = "DEBUG"
            Debug.Print iLevel, _
            Setting(iLevel, 0), _
            Setting(iLevel, 1), _
            Setting(iLevel, 2), _
            Setting(iLevel, 3), _
            Setting(iLevel, 4), _
   
    End Select

    Settings = Success           'Normal end - no errors

ErrHandler:
   
    If Err.Number <> 0 Then MsgBox _
        "Settings - Error#" & Err.Number & vbCrLf & Err.Description, _
        vbCritical, "Error", Err.HelpFile, Err.HelpContext
    On Error GoTo 0

End Function

Building a Library of Routines – ?Exists

We are early in the process of building a library of routines that will make creating analytical reports from database extracts a snap.  In our last post I explained the basic template that provides the skeleton for just about every function I write. 

Today, we are adding our first functions to our library - 5 of them.  These functions test to see if certain objects exist in our spreadsheet so we’ll know if we need to create them, or just refresh them (in some cases).   The first thing we need to do is create a module to contain these routines. 

1. Get to the VBE (Alt-F11)
2. From the VBE menu navigate Insert > Module
3. Rename the new Module from Module1 to modGeneral (using the Properties Window). 
4. Select and copy the code below
5. Paste into the Code Window (*see next paragraph)
6. Make any corrections to code that didn’t paste correctly
7. From the VBE menu navigate File > Export File…
8. Save modGeneral and remember where you saved it.

Unfortunately, the code won’t paste 100% properly.  You will have to add carriage returns and perhaps fix a few things until your code looks exactly like what you see here.  Yes – it’s a pain.  But it’s easier than typing it yourself and far easier than writing from scratch.  (If someone knows a better method, please let me know so I can improve this blog.  Thanks.)

Next Post: Settings routine – This routine puts XL on hold while VBA code runs to speed it along and prevent XL Worksheet events from firing when they shouldn’t.

'Version: 10/14/2009

'General Spreadsheet Routines

Option Explicit

Global Const Success = False
Global Const Failure = True
 

Function NameExists(sName As String) as Boolean

'   NameExists:     Determine if a name exists in a spreadsheet

'   Parameters:     sName - Name to be checked
'   Example:        If Not NameExists("Data") then Setup_Data("Data")

'     Date   Init Modification
'   01/01/01 CWH  Initial Programming

    On Error GoTo ErrHandler
    NameExists = False     'Assume not found
   
    Dim objName As Object
   
    For Each objName In Names
        If objName.Name = sName Then
            NameExists = Right(Names(sName).Value, 5) <> "#REF!"
            Exit For
        End If
    Next
   
ErrHandler:
   
    If Err.Number <> 0 Then MsgBox _
        "NameExists - Error#" & Err.Number & vbCrLf & Err.Description, _
        vbCritical, "Error", Err.HelpFile, Err.HelpContext
    On Error GoTo 0

End Function

Function ShapeExists(sName As String) as Boolean

'   ShapeExists:    See if a Shape Exists

'   Parameters:     sName - Shape Name to be checked
'   Example:        If not ShapeExists("EasyButton") then _
'		    Create_Easy_Button "easy", "Show_Prompt", 10, 8

'     Date   Init Modification
'   01/01/01 CWH  Initial Programming

    On Error GoTo ErrHandler
    ShapeExists = False     'Assume not found
   
    Dim objName As Object
   
    For Each objName In ActiveSheet.Shapes
        If objName.Name = sName Then
            ShapeExists = True
            Exit For
        End If
    Next

ErrHandler:
   
    If Err.Number <> 0 Then MsgBox _
        "ShapeExists - Error#" & Err.Number & vbCrLf & Err.Description, _
        vbCritical, "Error", Err.HelpFile, Err.HelpContext
    On Error GoTo 0

End Function

Function WorkSheetExists(sName As String) as Boolean

'   WorkSheetExists:See if a Worksheet Exists

'   Parameters:     sName - Worksheet Name to be checked
'   Example:        If not WorkSheetExists("Data") then Setup_Data("Data")

'     Date   Init Modification
'   01/01/01 CWH  Initial Programming

    On Error GoTo ErrHandler
    WorkSheetExists = False     'Assume not found
   
    Dim objName As Object
   
    For Each objName In Worksheets
        If objName.Name = sName Then
            WorkSheetExists = True
            Exit For
        End If
    Next
   
ErrHandler:
   
    If Err.Number <> 0 Then MsgBox _
        "WorkSheetExists - Error#" & Err.Number & vbCrLf & Err.Description, _
        vbCritical, "Error", Err.HelpFile, Err.HelpContext
    On Error GoTo 0

End Function

Function PivotTableExists(sWorksheet As String, sName As String) as Boolean

'   PivotTableExists:See if a PivotTable Exists

'   Parameters:     sName - PivotTable Name to be checked
'   Example:        If not PivotTableExists("pvtHrs") then Setup_pvtHrs

'     Date   Init Modification
'   01/01/01 CWH  Initial Programming

   On Error GoTo ErrHandler
    PivotTableExists = False     'Assume not found
   
    Dim objName As Object
   
    For Each objName InWorksheets(sWorksheet).PivotTables
        If objName.Name = sName Then
            PivotTableExists = True
            Exit For
        End If
    Next
   
ErrHandler:
   
    If Err.Number <>0 Then MsgBox _
        "PivotTableExists - Error#" & Err.Number & vbCrLf & Err.Description, _
        vbCritical, "Error", Err.HelpFile, Err.HelpContext
    On Error GoTo 0

End Function

Function ChartExists(sName As String) as Boolean
    
'   ChartExists:    See if a Chart Exists

'   Parameters:     sName - Chart Name to be checked
'   Example:        If not ChartExists("chtHrs") then Setup_chtHrs

'     Date   Init Modification
'   01/01/01 CWH  Initial Programming

    On Error GoTo ErrHandler
    ChartExists = False     'Assume not found

    Dim objName As Object
   
    For Each objName In Charts
        If objName.Name = sName Then
            ChartExists = True
            Exit For
        End If
    Next

ErrHandler:
   
    If Err.Number <> 0 Then MsgBox _
        "ChartExists - Error#" & Err.Number & vbCrLf & Err.Description, _
        vbCritical, "Error", Err.HelpFile, Err.HelpContext
    On Error GoTo 0

End Function

Building a Library of Routines – Template

Up until now, I have been showing you how to record and modify macros to bring data into a spreadsheet, format it, display it in a pivot table, and chart it.  While this method works, it leaves some housekeeping problems to be solved everytime you do it.  Enough. 

This post starts us on the path of creating a library of functions to “snap together” and (in a very few cases) modify to quickly produce our final product, ready for delivery to our waiting customers (Users). 

The first function, however, isn’t a function (sorry).  It’s a template for all other functions.  We’ll get this, and some theory, out of the way and then get right into building our library.  Here is the template:

'Template

'Use this to create your own functions.  The basic idea is everything that isn't
'tied to a button should be a function.  Functions can be called like Subroutines
'but can also be checked for Success or Failure return codes if needed.

'1) Replace every instance of "Template" to your routine's name
'2) Change the "As Boolean" if your function returns something other than
'   Success or Failure

Function Template() As Boolean

'   Routine Name:  Description of Routine

'   Parameters: None
'   Example:    bResult = Template(Parm1, Parm2)

'     Date   Init Modification
'   01/01/01 CWH  Initial Programming

    On Error GoTo ErrHandler            '
    Template = Failure                  'Assume the Worst

'   Begin code here

'   End code here
   
    Template = Success                  'Successful finish

ErrHandler:
   
    If Err.Number <> 0 Then MsgBox _
        "Template - Error#" & Err.Number & vbCrLf & Err.Description, _
        vbCritical, "Error", Err.HelpFile, Err.HelpContext
'   Begin additional error cleanup processing code here
    On Error Resume Next    'Remove this if no additional error cleanup processing
'   End   additional error cleanup processing code here
    On Error GoTo 0

End Function

The above template uses two user defined global constants: Success and Failure.  These constants provide more meaningful results for return codes than just True or False.  To define these constants and make them available throughout your project, you must add this tiny bit of code at the top of your module:

'Version: 10/09/2009

'General Spreadsheet Routines

Option Explicit

Global Const Success = False
Global Const Failure = True

This includes a comment to identify the version of your module.  Any time you change your module and save it, it’s a good idea to identify the version using the date.

I have also included a brief description of our library “General Spreadsheet Routines“.

The Option Explicit is a preference of mine.  It tells the VBA compiler not to accept any variables that haven’t been defined.  I use this because I make mistakes and I’d rather the compiler tell me when I have forgotten to properly define a variable than have my customers call me about a bug in my code.  If you don’t make mistakes, then by all means, remove this line – it’s useless otherwise.

Now – back to the template.  As you can see, there’s not much to it.  It’s just a shell with some error handling and places to put standard documention. 

Standard Documentation
It’s been my experience that most coders like to see a few things on any routine they might have to work on that they didn’t create themselves.  They want:

• A brief description of the routine (why it’s important)
• Defninitions for the parameters (if any)
• An example of how to use the routine
• A list of guilty parties, when they committed their crimes, and what the heck they were thinking

Error Handling
Like I said, I make mistakes.  Sometimes, so does XL/Windows.  That’s why error handling is critical.  You hope your users never experience an error, but if they do, they better never be plopped into your code.  They won’t know what to do and you’ll get a frustrated user’s call.  Only coders should see code.  So to make sure that happens, every routine should have error handling, and the first thing every routine does is to turn it on with “On Error GoTo ErrHandler”.

The second thing is to provide your routine with a default end state.  Most often, that’s Failure so unless your routine gets all the way to the end, it will accurately return Failure, not Success, and give the calling routine a chance to deal with it.

Many coders like to put an “Exit Function” just before the error handling routine.  I don’t.  I think it’s confusing.  Instead, I test for errors (If Err.Number <> 0 ).  If there are any, I leverage VBA’s error descriptions and present the user with an alert with whatever text VBA provides.  Hopefully, I’m the only one seeing these alerts during my testing.  In that case, the descriptions help greatly.  In any case, an alert is far better for the end user than being dumped into code.

In almost all cases, the error handling routines in the template work without modification, except for changing the name “Template” in the line “”Template – Error#” & Err.Number & vbCrLf & Err.Description, “.

To use the template, copy it, paste it, search and replace all instances of “Template” to your routine’s name, fix the documentation, and add code where designated.

Next posts: WorkSheetExists, PivotTableExists, ChartExists routines followed by: Settings; Setup_Pivot;  Setup_PivotChart; and finally, the Pivot_Template, the only routine in this bunch you’ll need to modify to easily make pivot tables and charts for your data.  Stay tuned.