I'm running into issues passing the user inputs into the Criteria object's constructor and exposed as a property of the Criteria for use in the DP_Fetch() method. Basically the issue is the user inputs are not passed even if the property of the ERO are set to the input values.
I called ValidateChildren () to set the properties of the ERO,but the ERO I passed to the Criteria is empty or only has initial values.
I did:
Private mSearchInput As New SearchInput
Private Sub Search_Click() Handles cmdSearch.Click
Me.ValidateChildren()
Me.SearchInputBindingSource.DataSource = objList.GetObjList(mSearchInput)
End Sub
The properities of the ERO has user inputs but mSearchInput doesn't, what did I miss?
Thanks in advance.
Below is a sample class I built for a search screen for account codes.The idea is that each control on the screen will be bound to the BO. So I have checkboxes on the left side and then dropdowns and textboxes for each field (acctcode, acctdesc, etc.)
When the user clicks search the screen is unbound into the BO and then the BO is passed to another BO as a parameter to its Fetch method. This way the Fetch method "knows" exactly what the user selected on the search screen.
The factory method of an ROC that returns the list of Accts the user is searching for looks like this:
Public Shared Function GetAcctList(ByVal AcctSearchCriteriaBO As AcctSearchCriteriaBO) As AcctListThe embedded Criteria class (there is more than 1) is given a new name of SearchCriteria and looks like this:
<Serializable()> _
Then the Fetch code is like this:
Protected Overrides Sub DataPortal_Fetch(ByVal criteria As Object)dr =
New SafeDataReader(DAL.ExecuteReader(strSQL)) While dr.ReadIsReadOnly =
True'use the checked properties only to include in the Search
'build a Filter for use in a SQL WHERE clause based on the dropdowns and text boxes.
'e.g. acctcode='123' AND acctdesc Like 'Joe%'
End Function
===================================================================
<Serializable()> _
Public Class AcctSearchCriteriaBO
Inherits MyBusinessBase(Of AcctSearchCriteriaBO)
#Region " Class Variable Declarations "
Protected mChkAcctCode As Boolean = False
Protected mChkAcctDesc As Boolean = False
Protected mChkRouteGrp As Boolean = False
Protected mChkStatus As Boolean = False
Protected mCboOperAcctCode As String = "starts with"
Protected mCboOperAcctDesc As String = "starts with"
Protected mCboOperRouteGrp As String = "starts with"
Protected mTxtAcctCode As String = ""
Protected mTxtAcctDesc As String = ""
Protected mTxtRouteGrp As String = ""
Protected mOpgStatus As String = "A"
Protected mOpgSort As String = "acctcode"
Protected mSortDirection As ListSortDirection = ListSortDirection.Ascending
Protected mLstSort As New ArrayList
#End Region
#Region " Constructor "
Protected Sub New()
'require use of factory methods
Me.Table = "Account Search Criteria"
End Sub
#End Region
#Region " Business Properties and Methods "
Public Overridable ReadOnly Property LstSort() As ArrayList
Get
If mLstSort.Count = 0 Then
mLstSort.Add(New DictionaryEntry("acctcode", "Account Code "))
mLstSort.Add(New DictionaryEntry("acctdesc", "Description "))
mLstSort.Add(New DictionaryEntry("routegrp", "Route Group "))
mLstSort.Add(New DictionaryEntry("statustext", "Active "))
End If
Return mLstSort
End Get
End Property
Public Overridable Property ChkAcctCode() As Boolean
Get
Return mChkAcctCode
End Get
Set(ByVal Value As Boolean)
mChkAcctCode = Value
End Set
End Property
Public Overridable Property ChkAcctDesc() As Boolean
Get
Return mChkAcctDesc
End Get
Set(ByVal Value As Boolean)
mChkAcctDesc = Value
End Set
End Property
Public Overridable Property ChkRouteGrp() As Boolean
Get
Return mChkRouteGrp
End Get
Set(ByVal Value As Boolean)
mChkRouteGrp = Value
End Set
End Property
Public Overridable Property ChkStatus() As Boolean
Get
Return mChkStatus
End Get
Set(ByVal Value As Boolean)
mChkStatus = Value
End Set
End Property
Public Overridable Property CboOperAcctCode() As String
Get
Return mCboOperAcctCode
End Get
Set(ByVal Value As String)
mCboOperAcctCode = Value
End Set
End Property
Public Overridable Property CboOperAcctDesc() As String
Get
Return mCboOperAcctDesc
End Get
Set(ByVal Value As String)
mCboOperAcctDesc = Value
End Set
End Property
Public Overridable Property CboOperRouteGrp() As String
Get
Return mCboOperRouteGrp
End Get
Set(ByVal Value As String)
mCboOperRouteGrp = Value
End Set
End Property
Public Overridable Property TxtAcctCode() As String
Get
Return mTxtAcctCode
End Get
Set(ByVal Value As String)
mTxtAcctCode = Value
PropertyHasChanged("TxtAcctCode")
End Set
End Property
Public Overridable Property TxtAcctDesc() As String
Get
Return mTxtAcctDesc
End Get
Set(ByVal Value As String)
mTxtAcctDesc = Value
PropertyHasChanged("TxtAcctDesc")
End Set
End Property
Public Overridable Property TxtRouteGrp() As String
Get
Return mTxtRouteGrp
End Get
Set(ByVal Value As String)
mTxtRouteGrp = Value
PropertyHasChanged("TxtRouteGrp")
End Set
End Property
Public Overridable Property OpgStatus() As String
Get
Return mOpgStatus
End Get
Set(ByVal Value As String)
mOpgStatus = Value
End Set
End Property
Public Overridable Property OpgSort() As String
Get
Return mOpgSort
End Get
Set(ByVal Value As String)
mOpgSort = Value
End Set
End Property
Public Overridable Property SortDirection() As ListSortDirection
Get
Return mSortDirection
End Get
Set(ByVal Value As ListSortDirection)
mSortDirection = Value
End Set
End Property
Public Overrides ReadOnly Property IsValid() As Boolean
Get
'Table level business rule is triggered here. This way the rule only runs once, when you check the validity of the BO.
ValidationRules.CheckRules("NoneChecked")
Return MyBase.IsValid
End Get
End Property
Public Overridable ReadOnly Property IsInvalid() As Boolean
Get
Return Not IsValid
End Get
End Property
#End Region
#Region " Validation Rules "
Protected Overrides Sub AddBusinessRules()
'NoneChecked
ValidationRules.AddRule(Of AcctSearchCriteriaBO, MyRuleArgs)(AddressOf AtLeastOneIsChecked, New MyRuleArgs("NoneChecked"))
End Sub
Private Shared Function AtLeastOneIsChecked(Of T As AcctSearchCriteriaBO, R As MyRuleArgs)(ByVal target As T, ByVal e As R) As Boolean
If Not (target.mChkAcctCode OrElse target.mChkAcctDesc OrElse target.mChkRouteGrp OrElse target.mChkStatus) Then
e.Description = "You must check at least one of the search criteria checkboxes."
Return False
Else
Return True
End If
End Function
#End Region
#Region " Factory Methods "
Public Shared Function NewAcctSearchCriteriaBO() As AcctSearchCriteriaBO
Return New AcctSearchCriteriaBO
End Function
#End Region
#Region " BusinessBase Overrides "
Protected Overrides Function GetIdValue() As Object
Return "AcctSearchCriteriaBO"
End Function
#End Region
End Class
Hope that helps.
Joe
Thank you Joe for posting your sample code here.
I have already built pretty much the same factory method of the ROC (like AcctList), embedded Criteria Class (like SearchCriteria), and the ERO (like AcctSearchCriteriaBO) that is used to be bound by search input controls in my project.
But the issue I'm having is that when the UI passes the AcctSearchCriteriaBO to the SearchCriteria is an empty object or only with its initial values. Therefore when the SearchCriteria is passed to the ROC(AcctList.GetAcctList) DP_Fetch method, it is also empty (doesn't have users' selection). I think my problem might be in the UI code as the BOs are defined almost the same as yours. I must have missed something somewhere in the UI.
This is the sample prototype UI code I used to pass the AcctSearchCriteriaBO (I will use the BO name in your example, for communication convenience):
Public Class AccountSearchControl
Private WithEvents mAcctSearchCriteriaBO As AcctSearchCriteriaBO = AcctSearchCriteriaBO.NewAcctSearchCriteriaBO
Private Sub Search_Click () Handles btnSearch.Click
AccountSearchCriteria.ValidateChildren()
AccountSearchResult.AcctListBindingSource.DataSource = AcctList.GetAcctList(mAcctSearchCriteriaBO)
End Sub
End Class
I do feel somthing is missed from the above code, but...
You said:
"When the user clicks search the screen is unbound into the BO and then the BO is passed to another BO as a parameter to its Fetch method. This way the Fetch method "knows" exactly what the user selected on the search screen."
I think this (the screen is unbound into the BO) is what I missed, therefore the factory method DOESN'T KNOW what the user selected.
What do I need to do to unbound the screen into the BO?
I have a few other questions regarding your sample:
1. The embedded Criteria class (there is more than 1) is given a new name of SearchCriteria and looks like this: >>>
Why do you need more than 1 embedded Criteria class? I thought the AcctSearchCriteriaBO encapsulated all the search criterias, is that not true?
2. In the following code
#Region " Factory Methods "
Public Shared Function NewAcctSearchCriteriaBO() As AcctSearchCriteriaBO
Return New AcctSearchCriteriaBO
End Function
#End Region
The code is all fine. But I'd like to know which way is preferred if I need to initialize some values for the AcctSearchCriteriaBO. Solution 1 : Add the initialization in the same function, something like this:
#Region " Factory Methods "
Public Shared Function NewAcctSearchCriteriaBO() As AcctSearchCriteriaBO
Dim obj As New AcctSearchCriteriaBO obj.TxtAcctCode = "9999"
Return obj
End Function
#End Region
Solution 2: use DP_Create method
#Region " Factory Methods "
Public Shared Function NewAcctSearchCriteriaBO() As AcctSearchCriteriaBO
Return DataPortal.Create(of AcctSearchCriteriaBO)
End Function
#End Region
Private Overloads Sub DataPortal_Create()
mTxtAcctCode = "9999"
End Sub
Thank you for your time.
Question #1 - simply means that I have other Criteria classes (with different names) that I can use to fetch the same list of Accts. The List BO is not always retrieved as the result of a Search screen.
Key Question:
I think this (the screen is unbound into the BO) is what I missed, therefore the factory method DOESN'T KNOW what the user selected.
You are correct - the web form does a postback and during the PageLoad of the postback you have to unbind the controls on the screen into your Search BO. In your case it would be best to set up a method (UnbindData or something) that is called when IsPostBack = True. In that method you simply set the porperties of the BO based on the values of the controls on the screen.
(I use 2 way databinding controls from Rick Strahl - so the unbinding happens "automatically" for me. But the method above accomplishes the same thing in a very clear way.)
Joe
Joe,
Thanks for your reply and advices.
Question #1 - Okay I see.
Key Question - Thanks for your suggestion to this key question. I think I probably didn't explain my issue clear in my last post and even in the original post of this thread.
My issue is:
The BO properties were updated, but the BO instance I created in the UI was not getting the updated property values (seems this is an even simpler problem). But I need to pass the BO instance with udpated property values ( = user inputs) into the GetList fatory method as parameter, and thereafter it is passed into Criteria class to do DP_Fetch method. Sorry for the confusion.
Here is what I did:
I called ValidateChildren() to trigger the setting of the BO properties based on the values of the controls on the screen, this is essentially doing the same thing as what the new method you suggested would do. Just instead of doing that in the method, the ValidateChildren() triggers the property setters in the BO, and I can see the properties are updated in the BO, but for some reason the BO instance I created in the UI code isn't getting those property values updated.
UI code looks something like this:
Public Class AccountSearchControl
Private WithEvents mAcctSearchCriteriaBO As AcctSearchCriteriaBO= _ AcctSearchCriteriaBO.NewAcctSearchCriteriaBO
Private Sub Search_Click () Handles btnSearch.Click
AccountSearchCriteria.ValidateChildren() AccountSearchResult.AcctListBindingSource.DataSource = AcctList.GetAcctList _(mAcctSearchCriteriaBO)
End Sub
End Class
Note:
My BO property getter and setter has CanReadProperty(), CanWriteProperty() and PropertyHasChanged(), may be there is something I don't know about having these in the getter and setter could change its behaviour?
Or am I way off to use the ValidateChildren() to trigger the setting of the BO properties?
Sorry for not expressing the issue clear enough in the pre posts, I hope I explained it clear now in this post.
I would appreciate any thoughts you have on this.
P.S. I also changed the topic of this thread to better describe the problem
1. Is ValidateChildren a method that you wrote? It does the unbinding? How?
2. Here is my Acct search form code: (State is a class that uses Session behind the scenes but allows for strong typing.)
Partial
Class AcctSearch
===============================================================================
This is the essential code on the Result page:
Partial
Class AcctResultsEnd Class
===============================================================================
My code looks a lot like yours. The basic difference is that when my form unbinds on postback my BO keeps its values. You need to debug your form and see why the BO gets the values set but then they disappear.
Joe
Joe,
1. ValidateChildren is not a method I wrote. It is:
Public Overrides Function ValidateChildren() As BooleanMember of: System.Windows.Forms.UserControl
2. Yeah, my code does look a lot like yours, mine is a windows application though.
The basic difference is that when my form unbinds on postback my BO keeps its values. You need to debug your form and see why the BO gets the values set but then they disappear. >>> You are absolutely right.
Note: I got the idea using ValidateChildren() to trigger the BO properties' setter by Rocky's post in following link
http://www.lhotka.net/Article.aspx?area=4&id=54b7097e-2eb5-476d-842b-98fde95c2006
I will post if I find anything in debugging.
The point of that article is to allow a dual-level validation scheme. One level is purely in the UI, the other is purely in the business object.
ValidateChildren() is there to validate the child controls in the UI. It has nothing really to do with the business object in any direct sense.
The assumption in the article you reference is that the UI allows entry of values that the object would never accept. In that case, the invalid value is in the UI, but not the object. The UI knows the value is bad, but leaves it on the screen for the user to see (probably along with an errorprovider indicator).
The code in the save button's click event first checks to see if ValidateChildren() returns true - which would indicate that there are no UI validation errors. If that check passes, we know that the values in the UI are in the object (since the UI liked the value, data binding put it in the business object automatically), and so the object's IsSavable property is checked.
Thanks Rocky for clarifying the usage of ValidationChildren() in your article, I have a better understanding of the purpose of that article now.
I tried, but I'm still not able to track down what the cause is that is making my BO properties disappear:
Recap of the scenario I'm trying to implement:
1. UI search control (with many user input controls on it) is bound to an Editable Businees Object Root
2. The BO has properties that are bound to each user input controls
3. Set BO properties with user inputs
4. Send the BO with user input values to the Criteria class
...
My problem resides in step 3, so let me step through what I did in step 3.
a. I called UIControl.ValidateChildren() from UI class to trigger the BO property setters.
The call stacks are as following:
Csla.dll!Csla.Core.BusinessBase.IEditableObject_BeginEdit() Line 650 Basic
> Csla.dll!Csla.Core.BusinessBase.CanWriteProperty(String propertyName = "ID", Boolean throwOnFalse = True)
> Csla.dll!Csla.Core.BusinessBase.CanWriteProperty(String propertyName = "ID")
> Csla.dll!Csla.Core.BusinessBase.VerifyAuthorizationCache()
> Csla.dll!Csla.Core.BusinessBase.get_AuthorizationRules()
> Csla.dll!Csla.Security.AuthorizationRules.HasWriteAllowedRoles(String propertyName = "ID")
> Csla.dll!Csla.Security.AuthorizationRules.get_InstanceRules()
> Csla.dll!Csla.Security.AuthorizationRulesManager.GetRolesForProperty(String propertyName = "ID")
> Csla.dll!Csla.Security.AuthorizationRules.HasWriteAllowedRoles(String propertyName = "ID")
> Csla.dll!Csla.Core.BusinessBase.PropertyHasChanged(String propertyName = "ID")
> Csla.dll!Csla.Core.BusinessBase.get_ValidationRules()
> Csla.dll!Csla.Core.BusinessBase.MarkDirty(Boolean suppressEvent = True)
> Csla.dll!Csla.Core.BindableBase.OnPropertyChanged(String propertyName = "ID")
> Csla.dll!Csla.Core.BindableBase.raise_PropertyChanged(Object sender = {Application.Business.MyBO}, System.ComponentModel.PropertyChangedEventArgs e = {System.ComponentModel.PropertyChangedEventArgs})
After these calls, in My BO class, the BO properties were updated
But right after the call of ValidationChildren(), if I do call the getter of the BO properties that were just updated, they already lost their updated values.
b. So If I do a test right after the UIControl.ValidateChildren() statement with something like
dim mSearchBO As SearchBO = SearchBO.NewInput
dim a As Int32
a = mSearchBO.ID
then a returns 0, which is its initial value
What did that happen? All the BO properties were not retained? What am I missing?
My BO property is set up like this:
Public
Property ID As Int32 GetCanReadProperty(
"ID", True) Return m_ID End Get Set (ByVal value As Int32)CanWriteProperty(
"ID", True) If m_ID <> value Thenm_ID = value
PropertyHasChanged("
ID") End If End Set End PropertyQuestions:
Am I completely off approaching this direction to implement my scenario? especially the part using ValidateChildren() to trigger BO property update
Is my BO property set up incorrectly? The calls to CanReadProperty, CanWriteProperty, and PropertyHasChanged, are they needed? (I tried to comment those line out but it didn't make difference)
Otherwise, why is this not working?
I appreciate any inputs/insights on this issue.
Why is there a step 3?
The whole point of data binding is so you don’t have to
set object properties – that’s done by data binding so you don’t
have to.
Rocky
RockfordLhotka: