Dynamic Data Custom Field Template updating a list

Question

I have a website using dynamic data and linq to sql. This website runs 3 'subsites' and has a list of categories with a many to many relationship.

I have 3 tables and hence 3 objects in my dbml; Website, Categories, and CategoriesToWebsites

What I am trying to do is create a field template such that on my Categories/Edit.aspx page I can edit a category and specify which website the category belongs in.

The field template is CategoriesToWebsites_Edit.ascx, which is basically a checkbox list bound to the list of websites.

Code below:

public partial class CategoriesToWebsitesEdit : FieldTemplateUserControl
{
    protected override void OnLoad(EventArgs e)
    {
        var dataSource = (LinqDataSource)this.FindDataSourceControl();

        dataSource.Inserting += OnInserting;
        dataSource.Updating += OnUpdating;
    }

    private void OnUpdating(object sender, LinqDataSourceUpdateEventArgs e)
    {
        var newCategory = (Category)e.NewObject;
        var oldCategory = (Category)e.OriginalObject;

        foreach(var listItem in WebsiteList.Items.Cast<ListItem>())
        {
            //check if website category already exists
            var categoryToWebsite = oldCategory.CategoriesToWebsites.FirstOrDefault(x => x.WebsiteId == Convert.ToInt32(listItem.Value));

            //website category exists
            if (categoryToWebsite != null)
            {
                // check if selected for removal, remove
                if (!listItem.Selected)
                {
                    newCategory.CategoriesToWebsites.Remove(categoryToWebsite);
                }
            }

            //we want to insert
            if (listItem.Selected)
            {
                //website category does not exist, add
                if (categoryToWebsite == null)
                {
                    //add selected website if not already exists
                    newCategory.CategoriesToWebsites.Add(new CategoriesToWebsite
                    {
                        WebsiteId = Convert.ToInt32(listItem.Value)
                    });
                }
            }


        }
    }

    private void OnInserting(object sender, LinqDataSourceInsertEventArgs e)
    {
        var category = (Category)e.NewObject;

        foreach(var listItem in WebsiteList.Items.Cast<ListItem>())
        {
            if(!listItem.Selected)
                continue;

            category.CategoriesToWebsites.Add(new CategoriesToWebsite
            {
                WebsiteId = Convert.ToInt32(listItem.Value)
            });
        }
    }

    protected override void OnDataBinding(EventArgs e)
    {
        var websiteRepository = new WebsiteRepository();
        var websites = websiteRepository.GetAll();

        var websiteCategories = (IEnumerable<CategoriesToWebsite>)FieldValue;

        foreach(var website in websites)
        {
            var currentWebsite = website;

            var listItem = new ListItem(website.Name, website.Id.ToString())
            {
                Selected = websiteCategories == null ? false : websiteCategories.Any(w => w.WebsiteId == currentWebsite.Id)
            };

            WebsiteList.Items.Add(listItem);
        }
    }
}

When I go to Categories/Insert.aspx to create a new category, it runs through the OnInserting code fine and saves it to db just fine, everything seems to be working here.

On Categories/Edit.aspx it goes through the code just as I expect, but does not seem to save anything.

What am I missing? - I'm not too familiar with Dynamic Data Field Templates so any guidance will be much appreciated

Answer 1

Apparently I was going about this slightly wrong. I was simply updating the object in the linq data source, which wasn't being saved. So instead I go straight to the repository:

private void OnUpdating(object sender, LinqDataSourceUpdateEventArgs e)
    {
        var newCategory = (Category)e.NewObject;
        var oldCategory = (Category)e.OriginalObject;

        var repository = new Repository<CategoriesToWebsite>();

        var ctw = repository.GetAll().Where(x => x.CategoryId == newCategory.Id);

        foreach (var listItem in WebsiteList.Items.Cast<ListItem>())
        {
            var current = ctw.FirstOrDefault(x => x.WebsiteId == Convert.ToInt32(listItem.Value));

            //current categoriesToWebsite exists
            if (current != null)
            {
                //if not selected, remove
                if (!listItem.Selected)
                    repository.Delete(current);
            }

            //does not exist
            else
            {
                //if selected, add
                if (listItem.Selected)
                    repository.Save(new CategoriesToWebsite()
                        {
                            CategoryId = newCategory.Id,
                            WebsiteId = Convert.ToInt32(listItem.Value)
                        }
                    );
            }
        }

        UnitOfWork.Current.SubmitChanges();
    }

I'm not sure if this is the proper way to do this since the field template here is doing some updating directly to the db. But it works.