Link list URL fields do not display when using FieldRenderingControl

Question

I'm creating a custom New Form for a Link list. Depending on the view depends which columns are displayed.

 for(int i = 0; i < spView.ViewFields.Count; i++)
                {
                    string fieldName = spView.ViewFields[i];
                    if (fieldName.Contains("LinkTitle"))
                        fieldName = "Title";


                    SPField field = spList.Fields.GetFieldByInternalName(fieldName);

                    if (field == null || field.FieldRenderingControl == null || field.Hidden)
                        continue;
                    Control cntrl = GetSharePointControls(field, spList, itemId);
                    if(cntrl == null) continue;
                   //Add control to webpart.
               }

Now to create the control I use the following code.

 internal static Control GetSharePointControls(SPField field, SPList list, int itemId)
    {
        // check if the field is a buildIn field, or can be rendered by a SharePoint Control
        if (field == null || field.FieldRenderingControl == null || field.Hidden) return null;

        Control ctrl = null;
        SPControlMode mode = SPControlMode.Invalid;

        if (itemId > 0)
            mode = SPControlMode.Edit;
        else
            mode = SPControlMode.New;


        var controlContext = SPContext.GetContext(System.Web.HttpContext.Current, itemId, list.ID,
                                                  SPContext.Current.Web);



        SPContext.Current.FormContext.SetFormMode(mode, true);
        controlContext.FormContext.SetFormMode(mode, true);


        try
        {
                BaseFieldControl webControl = field.FieldRenderingControl;
                webControl.ListId = list.ID;
                webControl.ControlMode = mode;
                webControl.ItemId = itemId;
                webControl.FieldName = field.Title;
                webControl.ID = GetControlID(field);

                webControl.RenderContext = controlContext;
                webControl.ItemContext = controlContext;

                ctrl = webControl;

            return ctrl;
        }

Now if I add a URL to a generic list, then this code works out the field is a URL field and displays the control correctly on the page. However, when using a Link list, the URL field type is a calculated column, which doesn't end up rendering on the page. I also found it strange that webControl.Visible = false; and if you change it in code to true, it still remains false.

I have also tried converting directly to a ComputedField instead of BaseFieldControl, but I end up with the same result. Has anyone else encountered this, or can see a fix for me? I might have to add extra logic for link lists, so that the field name URL is converted to a URLField.

Answer 1

I've solved my own question. (I seem to do that a lot on here).

The problem was that the URL field read in from my view had the internal name of UrlwMenu, where I actually wanted the internal name URL. Therefore I wrote a line of code that if field read in was UrlwMenu, then replace it with the Url field instead.

Also the line webControl.FieldName = field.Title should be

webControl.FieldName = field.InternalName

I found that when using Title if a column was renamed differently to the internal name some controls threw error messages of Cast Exceptions.