Question

Firstly, I have created a custom list definition based on the Tasks list in Visual Studio. This feature also creates an instance of that list titled “My Workflow Tasks”. Secondly, I have developed a custom workflow, again using Visual Studio. When I want to add my new workflow, I am not able to set My Workflow Tasks list to be used for workflow tasks. It is not listed in the drop-down of available lists that can be used.

Why is that? Could anyone explain what needs to be done in order to make it available? Thanks.

Answer 1

Here is the code from AddWrkfl.aspx that populates the dropdown:

    <select id="TaskList" name="TaskList" style="<SharePoint:EncodedLiteral runat='server' text='<%$Resources:wss,AddWrkfl_ListSelectionControlsStyle%>' EncodeMethod='HtmlEncode'/>" size="1" align="absmiddle" onchange="OnChangeSelectTaskList();">
<%
foreach (SPList list in Web.Lists)
{
    if (list.BaseTemplate == SPListTemplateType.Tasks)
    {
%>
    <option value=<%SPHttpUtility.AddQuote(SPHttpUtility.HtmlEncode(list.ID.ToString()),Response.Output);%>>
    <% SPHttpUtility.HtmlEncode(list.Title,Response.Output); %>
    </option>
<%
    }
}
%>
    <option id="OptCreateNewTaskList" value="" />
    </select>

Based on this, the ListTemplate element of your custom list definition would need to have a Type attribute value of 107 in order to be displayed in the dropdown.

Alternatively, you could try associating your workflow to your list programmatically within a feature receiver:

SPWorkflowTemplate template = web.WorkflowTemplates.GetTemplateByName(
    "My Workflow", 
    System.Globalization.CultureInfo.CurrentCulture);
SPWorkflowAssociation association = SPWorkflowAssociation.CreateListAssociation(
    template,
    "My Instance",
    web.Lists["My Workflow Tasks"],
    web.Lists["Workflow History"]);
list.WorkflowAssociations.Add(association);