How to pass parameters from Classic ASP to a com component

Question

I am developing an asp.net component that requires many parameters. It will be called from classic ASP. I can of course pass in 10-20 parameters, but I'd love to be a bit tidier.

I'm fairly confident I could pass in an array, but ideally I'd like to be able to pass in an object.

Is this possible?

I decided to do a little test. The Classic ASP:

Dim objDictionary
Set objDictionary = CreateObject("Scripting.Dictionary")

objDictionary.Add "startDate", startDate
objDictionary.Add "endDate", endDate

MyComponent.checkObj(objDictionary)

In my ASP.net component I have:

   public string checkObj(object config)
    {
        return "StartDate is " + config.startDate;
    }

Edit:

I have progressed the issue so I'm changing this: I created an abstract class and now it's checking against that and building perfectly. At run time I am now getting and error - Microsoft VBScript runtime error: Invalid procedure call or argument: 'checkObj' .

Is it possible to pass a collection into a com assembly?

Perhaps the problem is that the com component is receiving an object of type Scripting.Dictionary, and not the abstract class I created, but such a thing doesn't exist in .net?

Answer 1

you could try using a .net object in your asp page like System.Collections.ArrayList or System.Collections.Hashtable instead of that dictionary...

<%@ LANGUAGE="VBSCRIPT" %>
<%
dim netObj    
set netObj = server.createobject("System.Collections.Hashtable")
' or:
'set netObj = server.createobject("System.Collections.ArrayList")
%>

that should make things easier in your .net component

Answer 2

I wanted to do something similar and so created a wrapper class for .NET DataRow. You could use a HasTable/Dictionairy/Other Custom Implementation as your backing store if you want.

I expose my "properties" using an Indexer Property on my wrapper object, so working with a property in asp-classic would look like this:

Dim lngCustomerId
lngCustomerID = CLng(objectWrapper("CustomerId"))

I expose my wrapper using a COM Registered .NET assembly. My wrapper inherits from DynamicObject and exposes the following by a COM visible interface:

[ComVisible(true)]
[Guid("XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX")]
[InterfaceType(ComInterfaceType.InterfaceIsDual)]
public interface IDynamicModel
{
    dynamic this[string propertyName] { get; set; }
    bool TryGetMember(GetMemberBinder binder, out object result);
    bool TrySetMember(SetMemberBinder binder, object value);
}

I would think that TryGetMember and TrySetMember will not be necessary for your needs.

My wrapper class implementation looks like this:

[ComVisible(true)]
[Guid("YYYYYYYY-YYYY-YYYY-YYYY-YYYYYYYYYYYY")]
[ProgId("COMLIB.DynamicModel")]
[ClassInterface(ClassInterfaceType.None)]
public sealed class DynamicModel : DynamicObject, IDynamicModel
{
    #region indexer

    public dynamic this[string propertyName]
    {
        get
        {
            dynamic propertyValue;
            if (TryGetMember(propertyName, out propertyValue) != true)
            {
                propertyValue = null;
            }
            return propertyValue;
        }
        set
        {
            if (TrySetMember(propertyName, value) != true)
            {
                throw new ArgumentException("Cannot set property value");
            }
        }
    }

    #endregion indexer


    #region Fields

    private DataRow dataRow;

    #endregion Fields


    #region Properties

    public dynamic GetAsDynamic { get { return this; } }

    #endregion Properties


    #region CTOR Methods

    public DynamicModel()
        : base()
    {
        DataTable dataTable = new DataTable();
        this.dataRow = dataTable.NewRow();
    }

    public DynamicModel(DataRow dataRow)
        : base()
    {
        this.dataRow = dataRow;
    }

    #endregion CTOR Methods


    #region Dynamic Object Member Overrides

    public override bool TryGetMember(GetMemberBinder binder, out object columnValue)
    {
        bool result = false;
        columnValue = null;
        result = TryGetMember(binder.Name, out columnValue);
        return result;
    }

    public override bool TrySetMember(SetMemberBinder binder, object value)
    {
        bool result = false;
        result = TrySetMember(binder.Name, value);
        return result;
    }

    #endregion Dynamic Object Member Overrides


    #region Operations

    public bool TryGetMember(string columnName, out dynamic columnValue)
    {
        bool result = false;
        columnValue = null;
        if (dataRow != null && dataRow.Table.Columns.Contains(columnName))
        {
            columnValue = dataRow[columnName];
            result = true;
        }
        return result;
    }

    public bool TrySetMember(string columnName, dynamic columnValue)
    {
        bool result = false;
        if (dataRow != null && dataRow.Table.Columns.Contains(columnName) == true)
        {
            dataRow[columnName] = columnValue;
            result = true;
        }
        else
        {
            Type type = columnValue.GetType();
            DataColumn dataColumn = new DataColumn(columnName, type);
            result = TrySetDataColumn(dataColumn, type, columnValue);
        }
        return result;
    }

    private bool TrySetDataColumn(DataColumn dataColumn, Type type, object value)
    {
        bool result = false;
        dataRow.Table.Columns.Add(dataColumn);
        result = TrySetMember(dataColumn.ColumnName, value);
        return result;
    }

    #endregion Operations
}

I hope this helps.