Quick tip #2: Tracking form field change in WEBCON BPS

How to check if the WEBCON BPS form field has been modified in a universal way. Notification of a user about a change in the specific form field.

Business need

As part of my previous implementations of business applications, I met with the need to check whether a given form field has been modified. WEBCON BPS does not have a standard mechanism that would allow tracking whether the given form field has been modified. I had to create such a mechanism myself.

What can you track changes for?

There are many examples of the use of change tracking for the specific form field. Here are some examples:

• Change of value – if the amount changes (e.g. project budget) – the relevant processes are started
• Change of person – if the person changes – an email is sent to the person who has been entered in the field provided
• Change of date – if the date changes – the Exchange meeting is automatically modified

These are just a few examples. There are many more possibilities. Of course, each of the above examples could be handled with the help of dedicated transition paths, additional steps, etc.

However, remember – a good application is an intuitive application. Your application should be simple for end users – not for you. There may be dozens, hundreds or even thousands of users.

Universal business rule

Below is a universal business rule that you can use in your WEBCON BPS applications. You will be able to use it in the execution condition section.

NOTE: The following business rule is designed for actions configured on the entry to the step. The business rule presented will not work on the transition path.

DECLARE @sqlCommand NVARCHAR(max); 
DECLARE @columnName NVARCHAR(30); 
DECLARE @columnNameHistory NVARCHAR(30); 
DECLARE @currentValue NVARCHAR(max); 
DECLARE @currentVersion INT; 

SET @columnName = '{BRP:14}'; 

SELECT TOP 1 @currentValue = Cast({BRP:14} AS NVARCHAR(max)), 
             @currentVersion = wfd_version 
FROM   wfelements 
WHERE  wfd_id = {WFD_ID}; 

SET @columnNameHistory = (SELECT 'WFH_' 
                                 + RIGHT('{BRP:14}', Len('{BRP:14}') - 4)); 
SET @sqlCommand = 'If (Select top 1 isnull( cast(' 
                  + @columnNameHistory 
                  + 
' as nvarchar(max)), '''') from WFHistoryElements where WFH_OrgID = {WFD_ID} and WFH_Version = ' 
                  + Cast(@currentVersion AS NVARCHAR(max)) 
                  + '-1)  = ''' + Isnull(@currentValue, '') 
                  + ''' select 0 else select 1' 

EXEC(@sqlCommand)

And that’s all! It is a ready-to-use business rule. All you need to do is to replace the parameter in the SQL query. Now you may use this rule in the execution condition of action (just like below). As a parameter, you have to put the database column name (not a form value!). To fill it up, you need to find this variable in the right panel in the object tab of the “edit rule” window.