Inherit field editor control from SPUserField

Question

I need to implement AutoComplete feature for People Editor in custom field type derived from SPUserField. To do this, I have to customize both render template and field editor control (and other things).

As MSDN says, SPUSerfField is a field uses field editor control I cannot inherit from, but I need to implement switching from OOB People Editor Control to Custom People Editor.

So far, question is How can I inherit behavior of OOB UserFieldEditor to customize it in my own USerFieldEditorControl or somehow change basic behavior?

Answer 1

If you want to just inherit PeopleEditor you can do it, because it is a public class. Pasted from reflector:

[ValidationProperty("CommaSeparatedAccounts"), SharePointPermission(SecurityAction.InheritanceDemand, ObjectModel=true), AspNetHostingPermission(SecurityAction.InheritanceDemand, Level=AspNetHostingPermissionLevel.Minimal), SharePointPermission(SecurityAction.LinkDemand, ObjectModel=true), AspNetHostingPermission(SecurityAction.LinkDemand, Level=AspNetHostingPermissionLevel.Minimal)]
public class PeopleEditor : EntityEditorWithPicker {...}

So CustomPeopleEditor : Microsoft.SharePoint.WebControls.PeopleEditor will work just fine.

But in that linked article i can't find such a statement that you cannot inherit from it.

Answer 2

If someone needs, here is a way to implement this feature. While we cannot declaratively use UserFieldEditor Control in our CustomFieldEditor, we still can create it programmatically. To extend UserFieldEditor props, add whatever you need declaratively in your ascx page (InpuFormSection with some RadioButs in my case) and in your code-behind make this(Don't forget implement IFieldEditor interface):

protected UserFieldEditor Editor;

bool IFieldEditor.DisplayAsNewSection
    {
        get { return false; }
    }

protected override void OnInit(EventArgs e)
    {
        base.OnInit(e);

        Editor = (UserFieldEditor) Page.LoadControl("/_controltemplates/UserFieldEditor.ascx");
        Editor.DesignerInitialize();
        Controls.Add(Editor);
    }

void IFieldEditor.InitializeWithField(SPField field)
    {
        if (IsPostBack) return;
        Field = (MSTeamUserField) field;
        Editor.InitializeWithField(Field);
    }

    void IFieldEditor.OnSaveChange(SPField field, bool isNewField)
    {

        Field = (MSTeamUserField) field; // your custom field
        // apply your custom settings here
        Editor.OnSaveChange(field, isNewField); //Invoke UserFieldEditor OnSaveChange method 
    }

That's it! now you have your extended UserFieldEditorControl with all built-in settings.