StrataFrame Forum

Using Multiple BOs and BBSs in a DevEx Grid

http://forum.strataframe.net/Topic18139.aspx

By Bill Cunnien - 7/28/2008

The BOs are defined.  Relations exist.  The user wants a form that simply displays data from the BOs.  For example:

Work Order BO
workorderindex (pk)
workorderid
partindex (fk)

Parts BO
partindex (pk)
partnum
unitindex (fk)

Units BO
unitindex (pk)
unitdesc

The grid will display workorderid, partnum, unitdesc.  With only the BOs, their corresponding BBSs and a DevEx Grid, can this be done?  If so, how?

I can easily get the Work Order BO and the Parts BO to display everything I need (employing the appropriate repository controls in the grid).  The Units BO is the kicker.

Hoping someone in the SF community will have run into this issue and will be able to shine some light on this.  Please note that I do not want to resort to SQL script here.  I can certainly create a data query and pass the results to the grid and bypass the BOs altogether.  That is not what I want to do.  I have some custom properties that are showing up in the grid from the Work Order BO that I must have.  These will be lost if I bypass the BOs.

Thanks,
Bill

By Greg McGuffey - 7/28/2008

Bill,



If I understand you correctly, you could write a fill method in your Work Order BO that would return the appropriate data (using the appropriate SQL joins to the other tables). The data table under BO can have any column in it (i.e. there doesn't have to a strongly typed property associated with each column), to the extra data would be available in the underlying datatable. You would then have your custom properties. I'm a bit slow to make use of grids, so I'm not sure how the BBS works with a datatable like this, but if the BBS is just binding to the data table, I'd guess that it would work just fine.



Hope that sparks some ideas.
By Bill Cunnien - 7/28/2008

you could write a fill method in your Work Order BO

So, I could write something like FillDataTable("SELECT WO.*, Parts.partnum, Units.unitdesc FROM WorkOrders WO LEFT OUTER JOIN...") and these two fields will show up in the BBS?  Is that right?  If so...my problem might be solved.

Testing now.

By Bill Cunnien - 7/28/2008

That does not work.  The fields come back with blank stares.  Kinda creepy.

As I understand it, the BO must have the field defined in order for the BBS to pick it up.  It has to be a part of the CurrentDataTable of the BO.  That is why I really want to see if this can be down only using currently defined BOs.  All of the data I need already exists in these separate BO definitions.  They can be instantiated and filled quite quickly.  Somehow, I should be able to relate the BOs and point to the field I want to display in the grid.  Somehow.

I really do not want to create a custom property in the Work Order BO called UnitDesc.  I shudder just thinking about that.

Thanks for the help!
Bill

By Peter Jones - 7/28/2008

Hi Bill,

I may be missing the point but isn't this just three DX grids: Parent, Child and GrandChild using the SF ParentRelationship and ParentBusinessObject properties to bind them together?

Cheers, Peter

By Bill Cunnien - 7/28/2008

One grid.  Three BOs.  Three BBSs.  Just looking for a simple, flattened view of the data.  I do not need any of the master-detail type stuff going on in this particular DevEx grid.

Please keep in mind that this is an exercise for the use of SF BOs.  If a business object exists, then I should be able to point to its properties.  If one of the properties has a relation to another BO, then I should also be able to point to that second BOs properties, too.  The fundamental question is, can it be done in a grid format, using it as a table-like representation of the data?

Hope I am making myself clear--doesn't sound like it, though.  Holler if anyone needs more clarification.

Bill

By Peter Jones - 7/28/2008

Hi Bill,

Yes, I see now. Personally I would just create a view (and replicate your custom fields in the view) that brings everything together however I'm pretty sure you will see examples of bringing BO's together in this fashion for reporting. Try a forum search on reporting, especially SharpShooter examples.

Cheers, Peter

By Bill Cunnien - 7/29/2008

just create a view (and replicate your custom fields in the view)

If I create a view (which is what I have always done up to this point...again, I am exploring the business object capabilities), then I also have to create a corresponding BO.  This new BO would easily populate the grid that I want.  I'll grant that option.  It is what I will be doing if no other clever solution comes my way.

I'd really like to take existing BOs that can be related to one another and display the flattened view of the data, including any custom properties of any of the BOs.  Perhaps this is simply not possible.  I am probably attempting something that the framework is not intended to do.

By Trent L. Taylor - 7/29/2008

So, I could write something like FillDataTable("SELECT WO.*, Parts.partnum, Units.unitdesc FROM WorkOrders WO LEFT OUTER JOIN...") and these two fields will show up in the BBS?  Is that right?  If so...my problem might be solved.

Actually this isn't far off.  There are a couple of things that you may want to consider.  First, I more than likely would not be trying to put all 3 tables inside of one grid unless they are all one-to-one relationships.  Otherwise this would get really messy.  In this case though, you would just want to create an updatable view which pulls this back and would then allow a record set to be updated going back the other way. 

What you are trying to accomplish is not outside of the scope of the framework and can be done, but the reason that you have received some of the comments suggesting other mechanisms is because a grid gets really messy when trying to cram all of this into one locale.  If this were read-only then it wouldn't be as big of a deal.  But in any case, just create an updatable view, then all of your BOs, custom properties, etc. will all work.  You can then create a new Custom BBS through the templates which will just side step the need to drop on a separate BBS on the form (same approach that is used for reporting).

Note: When creating updatable views, you must still specify a primary key field.  To do this, open up the BO Mapper, right-click the BO in question, then open the advanced section.  Then override the PK field and specify a PK so that the updates will work properly.

By Dustin Taylor - 7/29/2008

One more approach on top of Trent's suggestion is to bring everything into the Work Orders BO. Greg's already hit on this, the only additional thing you would need to do is create public properties and custom bindable property descriptors so that the BBS will recognize those new fields. 

As Trent said, however, doing it this way (pulling everything into a single BO) would only work if the data is meant to be read only. If you want to be able to update the data through the grid, you will need to use Trent's suggestion of the  updateable view.

If the grid is read only, and you do want to handle it all via the work orders BO, then your original response to Greg is most of the way there.  Once the custom fields are pulled in via your custom query (just like you described in your original reply to Greg), you will need to expose them via public properties on the work order BO:

#Region " Public Properties "


        ''' <summary>
        ''' Part Index (Primary Key)
        ''' </summary>
        ''' <value></value>
        ''' <returns></returns>
        ''' <remarks></remarks>
        Public ReadOnly Property parts_partindex() As String
            Get
                Return CType(Me.CurrentRow.Item("parts_partindex"), String)
            End Get
        End Property

        ''' <summary>
        ''' Part Number
        ''' </summary>
        ''' <value></value>
        ''' <returns></returns>
        ''' <remarks></remarks>
        Public ReadOnly Property parts_partnum() As String
            Get
                Return CType(Me.CurrentRow.Item("parts_partnum"), String)
            End Get
        End Property

        ''' <summary>
        ''' Part Unit Index (Foreign Key)
        ''' </summary>
        ''' <value></value>
        ''' <returns></returns>
        ''' <remarks></remarks>
        Public ReadOnly Property parts_unitindex() As String
            Get
                Return CType(Me.CurrentRow.Item("parts_unitindex"), String)
            End Get
        End Property

        ''' <summary>
        ''' Unit Index (Primary Key)
        ''' </summary>
        ''' <value></value>
        ''' <returns></returns>
        ''' <remarks></remarks>
        Public ReadOnly Property units_unitindex() As String
            Get
                Return CType(Me.CurrentRow.Item("units_unitindex"), String)
            End Get
        End Property

        ''' <summary>
        ''' Unit Description
        ''' </summary>
        ''' <value></value>
        ''' <returns></returns>
        ''' <remarks></remarks>
        Public ReadOnly Property units_unitdesc() As String
            Get
                Return CType(Me.CurrentRow.Item("units_unitdesc"), String)
            End Get
        End Property

#End Region

And then provide custom property descriptors on the work order BO to access those custom fields:

Protected Overrides Function GetCustomBindablePropertyDescriptors() As FieldPropertyDescriptor()
    Return New FieldPropertyDescriptor() { _
        New ReflectionPropertyDescriptor("parts_partindex", GetType(WorkOrderBO)), _
        New ReflectionPropertyDescriptor("parts_partnum", GetType(WorkOrderBO)), _
        New ReflectionPropertyDescriptor("parts_unitindex", GetType(WorkOrderBO)), _
        New ReflectionPropertyDescriptor("units_unitindex", GetType(WorkOrderBO)), _
        New ReflectionPropertyDescriptor("units_unitdesc", GetType(WorkOrderBO))}
End Function
By Bill Cunnien - 7/29/2008

Sorry.  My communication skills do lack.  Getting what is in my brain onto paper has always been difficult.  I apologize in advance if I sound like I am repeating myself.

The grid is going to be read-only.  The user just wants to view the data (and I may whip out a report or two from the grid).  I am trying to get fields from three tables into one table-like presentation to the user.  Since the three BOs already exist, I was hoping to utilize some functionality there.  Since relations exist, couldn't I somehow derive a table from the three BOs and throw that into the grid?

Just exploring.

By Bill Cunnien - 7/29/2008

Dustin,

Much appreciated response!  I do not want to "complicate" things by adding custom properties to the first BO which reflect the already existing properties of the second and third BO.  I think that I may be trying to do something with business objects that they were not intended to do.  In other words, I cannot "query" (derive a table from) the business objects...I need to go back to the source DB for that.

Bill

By Greg McGuffey - 7/29/2008

Bill,



OK, so the BBS needs to have a strong typed property to work...didn't know that.



However, you might want to consider a ListView instead, since the data is readonly. In this case, you don't need strong typed properties, just columns in the underlying data table (they must be aliased in SQL though). You might have set up the population setting via code, but it works...I'm using heavily in a custom search form I use. In my case, I'm allowing the user to search on not just the base table, but also on values in a parent table and/or other FK tables. E.g. in your case, this would allow the user to search on unit description to retrieve a work order. I build the list view based on columns in the data table. You just need to alias all the columns in SQL. I don't think you can set this up via the designer, as it will only show you the strongly typed properties.



Of course, if you need to pump out reports, then you may be back to a grid....which means either adding the custom properties to the appropriate BO or creating a special BO based on a view. You may find that the custom properties are the way to go, as they might have other uses. If you use them, you'd just need to add these columns to your fill methods, then access the extra columns in you properties. There are lots of good posts on this out there.



Hope that helps! BigGrin
By Dustin Taylor - 7/29/2008

Ok, what about using custum business binding sources to expose the children BOs themselves as properties on the parent BO? This is the same way we do reporting, and there is an example of how to set this up within the new StrataFlix sample that Trent just posted: http://forum.strataframe.net/Topic18186-17-1.aspx

Take a look at the Movie Profile Report under the StrataFlix.Reporting project.  The Movies BO has Images, Cast, and Items as children all declared as public properties. Notice that you are talking to the business binding source for each child BO rather than the BO itself. You aren't pulling in the individual fields into the parent BO (i.e. the solution I suggested earlier), but are instead exposing the children BOs themselves.

For a grandchild record, you would just go one level deeper and expose the grandchild BBS as a public property on the child BO.

Does that sound more like what you are looking for?

By Trent L. Taylor - 7/29/2008

You will want to take Dustin's advice on this one.  This will give you what you are trying to accomplish.
By Bill Cunnien - 7/29/2008

Does that sound more like what you are looking for?

It does.  I have downloaded the sample app and the newest posting of the framework.  I have 1.6.6, but it is not the most recent beta version.  As soon as I can get these things installed and built, I will review the sample app.  Hopefully, this will provide what I am looking for.

Thanks!
Bill

By Bill Cunnien - 7/29/2008

Error encountered:
A project with an Output Type of Class Library cannot be started directly.
In order to debug this project, add an executable project to this solution which references the library project.  Set the executable project as the startup project.

Solution: 
For some reason StrataFlix.Base was set as the startup project.  I changed it to StrataFlix (first project in the list) and everything worked after that.

Now, I will start digging into the custom BBS examples.

By Trent L. Taylor - 7/29/2008

That is stored on a per machine basis as part of the solution.  This is just .NET.