Call it a code generator, software factory, or just a clever script. If you can write
code that writes code - you win, even if just a small victory for humans in this contest we
call software development.
For example, I've been working on an ASP.NET application which contains many data
entry screens. You know the kind: very simple, table-format with a label and
a textbox of a certain width, that may or may not require some validation.
In other words, a whole lot of markup like this:
<tr>
<td class="EditLabel">Number</td>
<td class="Edit">
<asp:TextBox ID="txtNumber" runat="Server"
Width="200px" MaxLength="20"></asp:TextBox>
</td>
</tr>
Now, if you have to type the above more than once or twice, you will go insane (been
there, gone there). More importantly, you will probably introduce a bug or two.
So, I opened up SQL Server 2005 Management Studio and wrote the following T-SQL code:
USE SomeDB
GO
DECLARE @Table varchar(128)
DECLARE @Column varchar(128)
DECLARE @Width varchar(10)
DECLARE @Length int
DECLARE @Type int
SET @Table = 'Employer' -- Pass this as a parameter
DECLARE ColumnCursor CURSOR FOR
SELECT C.Name, C.Max_Length, C.User_Type_ID
FROM Sys.Columns C
INNER JOIN Sys.Tables T ON C.Object_ID = T.Object_ID
WHERE T.Name = @Table
ORDER BY Column_ID
OPEN ColumnCursor
FETCH NEXT FROM ColumnCursor INTO @Column, @Length, @Type
WHILE @@FETCH_STATUS = 0
BEGIN
IF @Type <> 36 -- No GUIDs
BEGIN
IF @Length < 0 SET @Length = 100
IF @Length < 10
SET @Width = '50px'
ELSE IF @Length < 20
SET @Width = '100px'
ELSE IF @Length < 50
SET @Width = '200px'
ELSE IF @Length < 100
SET @Width = '300px'
ELSE
SET @Width = '400px'
PRINT '<tr>'
PRINT ' <td class="EditLabel">'
+ @Column + '</td>'
PRINT ' <td class="Edit">'
PRINT ' <asp:TextBox
ID="txt' + @Column + '" runat="Server" Width="' + @Width + '" MaxLength="' + CONVERT(varchar(10),@Length)
+ '"></asp:TextBox>'
PRINT ' </td>'
PRINT '</tr>'
END
FETCH NEXT FROM ColumnCursor INTO @Column, @Length,
@Type
END
CLOSE ColumnCursor
DEALLOCATE ColumnCursor
You get the picture. Feel free to customize this code to introduce additional formatting,
a slick UI, or other business rules to the mix.
